The modulation of physicochemical characterization of innovative liposomal platforms: the role of the grafted thermoresponsive polymers.

PubMed

Chountoulesi, Maria; Kyrili, Aimilia; Pippa, Natassa; Meristoudi, Anastasia; Pispas, Stergios; Demetzos, Costas

2017-05-01

This study is focused on chimeric advanced drug delivery systems and specifically on thermosensitive liposomes, combining lipids and thermoresponsive polymers. In this investigation, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) chimeric liposomal systems were prepared, incorporating the homopolymer C 12 H 25 -poly(N-isopropylacrylamide)-COOH (C 12 H 25 -PNIPAM-COOH) and the block copolymer poly(n-butylacrylate-b-N-isoropylacrylamide) (PnBA-PNIPAM), at six different molar ratios. Both of these polymers contain the thermoresponsive PNIPAM block, which exhibits lower critical solution temperature (LCST) at 32 °C in aqueous solutions, changing its nature from hydrophilic to hydrophobic above LCST. During the preparation of liposomes, the dispersions were observed visually, while after the preparation we studied the alterations of the physicochemical characteristics, by measuring the size, size distribution and ζ-potential of prepared liposomes. The presence of polymer, either C 12 H 25 -PNIPAM-COOH or PnBA-PNIPAM, resulted in liposomes exhibiting different physicochemical characteristics in comparison to conventional DPPC liposomes. At the highest percentage of the polymeric guest, chimeric liposomes were found to retain their size during the stability studies. The incorporation of the appropriate amount of these novel thermoresponsive polymers yields liposomal stabilization and imparts thermoresponsiveness, due to the functional PNIPAM block.

50th Anniversary Perspective: A Perspective on Polyelectrolyte Solutions

PubMed Central

2017-01-01

From the beginning of life with the information-containing polymers until the present era of a plethora of water-based materials in health care industry and biotechnology, polyelectrolytes are ubiquitous with a broad range of structural and functional properties. The main attribute of polyelectrolyte solutions is that all molecules are strongly correlated both topologically and electrostatically in their neutralizing background of charged ions in highly polarizable solvent. These strong correlations and the necessary use of numerous variables in experiments on polyelectrolytes have presented immense challenges toward fundamental understanding of the various behaviors of charged polymeric systems. This Perspective presents the author’s subjective summary of several conceptual advances and the remaining persistent challenges in the contexts of charge and size of polymers, structures in homogeneous solutions, thermodynamic instability and phase transitions, structural evolution with oppositely charged polymers, dynamics in polyelectrolyte solutions, kinetics of phase separation, mobility of charged macromolecules between compartments, and implications to biological systems. PMID:29296029

Coupling the Alkaline-Surfactant-Polymer Technology and the Gelation Technology to Maximize Oil Production

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

Malcolm Pitts; Jie Qi; Dan Wilson

2005-12-01

Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or reservoirs with different sand lenses with high permeability contrast. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more crude oil than waterflooding froin swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or reservoirs with high permeability contrast zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. Fluid-fluid interaction withmore » different gel chemical compositions and alkaline-surfactant-polymer solution with pH values ranging from 9.2 to 12.9 have been tested. Aluminum-polyacrylamide gels are not stable to alkaline-surfactant-polymer solutions at any pH. Chromium-polyacrylamide gels with polymer to chromium ion ratios of 25 or greater were stable to alkaline-surfactant-polymer solutions if solution pH was 10.6 or less. When the polymer to chromium ion was 15 or less, chromium-polyacrylamide gels were stable to alkaline-surfactant-polymer solutions with pH values up to 12.9. Chromium-xanthan gum gels were stable to alkaline-surfactant-polymer solutions with pH values of 12.9 at the polymer to chromium ion ratios tested. Silicate-polyacrylamide, resorcinol-formaldehyde, and sulfomethylated resorcinol-formaldehyde gels were also stable to alkaline-surfactant-polymer solutions with pH values ranging from 9.2 to 12.9. Iron-polyacrylamide gels were immediately destroyed when contacted with any of the alkaline-surfactant-polymer solutions with pH values ranging from 9.2 to 12.9. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses with the exception of the xanthan gum-chromium acetate gels. Aluminum-polyacrylamide flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9, either in linear corefloods or in dual separate radial core, common manifold corefloods. Chromium acetate-polyacrylamide flowing and rigid tonguing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid tonguing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Chromium acetate gels were stable to injection of alkaline-surfactant-polymer solutions at 72 F, 125 F and 175 F in linear corefloods. Chromium acetate-polyacrylamide gels maintained diversion capability after injection of an alkaline-surfactant-polymer solution in stacked; radial coreflood with a common well bore. Chromium acetate-polyacrylamide gel used to seal fractured core maintain fracture closure if followed by an alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection at 72, 125, and 175 F. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent alkaline-surfactant-polymer injected solution were observed. Aluminum citrate-polyacrylamide, resorcinol-formaldehyde, and the silicate-polyacrylamide gel systems did not produce significant incremental oil in linear corefloods. Both flowing and rigid tonguing chromium acetate-polyacrylamide gels and the xanthan gum-chromium acetate gel system produced incremental oil with the rigid tonguing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. Aluminum citrate-polyacrylamide gels, chromium acetate-polyacrylamide gels, silicate-polymer, and chromium-xanthan guin gels did not alter an alkaline-surfactant-polymer solution's ability to produce incremental oil. Incremental oil was reduced with the resorcinol-formaldehyde gel system. Total waterflood plus chemical flood oil recovery sequence recoveries were generally similar.« less

Significant Stability Enhancement in High-Efficiency Polymer:Fullerene Bulk Heterojunction Solar Cells by Blocking Ultraviolet Photons from Solar Light.

PubMed

Jeong, Jaehoon; Seo, Jooyeok; Nam, Sungho; Han, Hyemi; Kim, Hwajeong; Anthopoulos, Thomas D; Bradley, Donal D C; Kim, Youngkyoo

2016-04-01

Achievement of extremely high stability for inverted-type polymer:fullerene solar cells is reported, which have bulk heterojunction (BHJ) layers consisting of poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene-alt-3-fluorothieno[3,4-b]thiophene-2-carboxylate] (PTB7-Th) and [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM), by employing UV-cut filter (UCF) that is mounted on the front of glass substrates. The UCF can block most of UV photons below 403 nm at the expense of ≈20% reduction in the total intensity of solar light. Results show that the PTB7-Th:PC 71 BM solar cell with UCF exhibits extremely slow decay in power conversion efficiency (PCE) but a rapidly decayed PCE is measured for the device without UCF. The poor device stability without UCF is ascribed to the oxidative degradation of constituent materials in the BHJ layers, which give rise to the formation of PC 71 BM aggregates, as measured with high resolution and scanning transmission electron microscopy and X-ray photoelectron spectroscopy. The device stability cannot be improved by simply inserting poly(ethylene imine) (PEI) interfacial layer without UCF, whereas the lifetime of the PEI-inserted PTB7-Th:PC 71 BM solar cells is significantly enhanced when UCF is attached.

Investigation of Resin Systems for Improved Ablative Materials

DTIC Science & Technology

1966-04-01

condensed rings, Boron linear chain of rings Carboranes B-P Resins Polymers Containing Si-O Silicon Si -C Si -N Furan Derivatives Furfural Base Furfural ...8217 Adsorption Theory of Adhesion’ presented at the 144th American Chemical Society Meeting, held in Los Angeles, April 1963. 15. Freeman, J. H. , L. W

Coupling the Alkaline-Surfactant-Polymer Technology and The Gelation Technology to Maximize Oil Production

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

Malcolm Pitts; Jie Qi; Dan Wilson

2005-12-01

Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or reservoirs with different sand lenses with high permeability contrast. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more crude oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or reservoirs with high permeability contrast zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. Fluid-fluid interaction withmore » different gel chemical compositions and alkaline-surfactant-polymer solution with pH values ranging from 9.2 to 12.9 have been tested. Aluminum-polyacrylamide gels are not stable to alkaline-surfactant-polymer solutions at any pH. Chromium-polyacrylamide gels with polymer to chromium ion ratios of 25 or greater were stable to alkaline-surfactant-polymer solutions if solution pH was 10.6 or less. When the polymer to chromium ion was 15 or less, chromium-polyacrylamide gels were stable to alkaline-surfactant-polymer solutions with pH values up to 12.9. Chromium-xanthan gum gels were stable to alkaline-surfactant-polymer solutions with pH values of 12.9 at the polymer to chromium ion ratios tested. Silicate-polyacrylamide, resorcinol-formaldehyde, and sulfomethylated resorcinol-formaldehyde gels were also stable to alkaline-surfactant-polymer solutions with pH values ranging from 9.2 to 12.9. Iron-polyacrylamide gels were immediately destroyed when contacted with any of the alkaline-surfactant-polymer solutions with pH values ranging from 9.2 to 12.9. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses with the exception of the xanthan gum-chromium acetate gels. Aluminum-polyacrylamide flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9, either in linear corefloods or in dual separate radial core, common manifold corefloods. Chromium acetate-polyacrylamide flowing and rigid tonguing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid tonguing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Chromium acetate gels were stable to injection of alkaline-surfactant-polymer solutions at 72 F, 125 F and 175 F in linear corefloods. Chromium acetate-polyacrylamide gels maintained diversion capability after injection of an alkaline-surfactant-polymer solution in stacked; radial coreflood with a common well bore. Chromium acetate-polyacrylamide gel used to seal fractured core maintain fracture closure if followed by an alkaline-surfactant-polymer solution. Chromium acetatexanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection at 72, 125, and 175 F. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent alkaline-surfactant-polymer injected solution were observed. Aluminum citrate-polyacrylamide, resorcinol-formaldehyde, and the silicate-polyacrylamide gel systems did not produce significant incremental oil in linear corefloods. Both flowing and rigid tonguing chromium acetate-polyacrylamide gels and the xanthan gum-chromium acetate gel system produced incremental oil with the rigid tonguing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. Aluminum citrate-polyacrylamide gels, chromium acetate-polyacrylamide gels, silicate-polymer, and chromium-xanthan gum gels did not alter an alkaline-surfactant-polymer solution's ability to produce incremental oil. Incremental oil was reduced with the resorcinol-formaldehyde gel system. Total waterflood plus chemical flood oil recovery sequence recoveries were generally similar. Performance and produced polymer evaluation of four alkaline-surfactant-polymer projects concluded that only one of the projects could have benefited from combining the alkaline-surfactant-polymer and gelation technologies. Cambridge, the 1993 Daqing, Mellott Ranch, and the Wardlaw alkaline-surfacant-polymer floods were studied. An initial gel treatment followed by an alkaline-surfactant-polymer flood in the Wardlaw field would have been a benefit due to reduction of fracture flow.« less

Ultrahigh molecular weight aromatic siloxane polymers

NASA Technical Reports Server (NTRS)

Ludwick, L. M.

1982-01-01

The condensation of a diol with a silane in toluene yields a silphenylene-siloxane polymer. The reaction of stiochiometric amounts of the diol and silane produced products with molecular weights in the range 2.0 - 6.0 x 10 to the 5th power. The molecular weight of the product was greatly increased by a multistep technique. The methodology for synthesis of high molecular weight polymers using a two step procedure was refined. Polymers with weight average molecular weights in excess of 1.0 x 10 to the 6th power produced by this method. Two more reactive silanes, bis(pyrrolidinyl)dimethylsilane and bis(gamma butyrolactam)dimethylsilane, are compared with the dimethyleminodimethylsilane in ability to advance the molecular weight of the prepolymer. The polymers produced are characterized by intrinsic viscosity in tetrahydrofuran. Weight and number average molecular weights and polydispersity are determined by gel permeation chromatography.

Chlorination of Side Chains: A Strategy for Achieving a High Open Circuit Voltage Over 1.0 V in Benzo[1,2-b:4,5-b']dithiophene-Based Non-Fullerene Solar Cells

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

Chao, Pengjie; Mu, Zhao; Wang, Huan

Here, a benzo[1,2-b:4,5-b']dithiophene-based donor material with chlorine atoms substituted on its side chains, named PBClT, was designed and developed for application in non-fullerene solar cells to enhance the open-circuit voltage ( V oc) without decreasing charge carrier transfer in the corresponding blend films. The results demonstrated that the chlorinated PBClT polymer was an efficient donor in non-fullerene polymer solar cells (PSCs) and exhibited a blue-shifted absorbance, resulting in more complementary light absorption with non-fullerene acceptors, such as ITIC. In addition, the chlorine substitution decreased the HOMO level of PBClT, and as a result, the V oc of the corresponding solarmore » cell increased dramatically to 1.01 V, which is much higher than that of the non-chlorine analog, PTB7-Th, with a V oc of approximately 0.82 V. The 2D-GIWAX results illustrated that the PBClT/ITIC blend film exhibited a “face-on” orientation, which suggested that the chlorine substituents on the side chains favored π-π stacking in the direction perpendicular to the electron flow in photovoltaic devices. Furthermore, the PBClT/ITIC blend film showed a π-π stacking distance of 3.85 Å, which was very close to that of its non-chlorine analog blend film with a distance of approximately 3.74 Å. Based on this result, the introduction of multiple chlorine atoms on the conjugated side chains not only adjusted the energy level of the low-band-gap polymer through the electron withdrawing ability of the chlorine atoms but also subtly avoided obvious morphological changes that could result from strong steric hindrance in the main chain of the polymers. The PBClT/ITIC-based PSCs exhibited a maximum PCE of 8.46% with a V oc of 1.01 V, which is an increase in the PCE of approximately 22% compared to the PTB7-Th-based device based on our parallel experiments.« less

Chlorination of Side Chains: A Strategy for Achieving a High Open Circuit Voltage Over 1.0 V in Benzo[1,2-b:4,5-b']dithiophene-Based Non-Fullerene Solar Cells

DOE PAGES

Chao, Pengjie; Mu, Zhao; Wang, Huan; ...

2018-04-23

Here, a benzo[1,2-b:4,5-b']dithiophene-based donor material with chlorine atoms substituted on its side chains, named PBClT, was designed and developed for application in non-fullerene solar cells to enhance the open-circuit voltage ( V oc) without decreasing charge carrier transfer in the corresponding blend films. The results demonstrated that the chlorinated PBClT polymer was an efficient donor in non-fullerene polymer solar cells (PSCs) and exhibited a blue-shifted absorbance, resulting in more complementary light absorption with non-fullerene acceptors, such as ITIC. In addition, the chlorine substitution decreased the HOMO level of PBClT, and as a result, the V oc of the corresponding solarmore » cell increased dramatically to 1.01 V, which is much higher than that of the non-chlorine analog, PTB7-Th, with a V oc of approximately 0.82 V. The 2D-GIWAX results illustrated that the PBClT/ITIC blend film exhibited a “face-on” orientation, which suggested that the chlorine substituents on the side chains favored π-π stacking in the direction perpendicular to the electron flow in photovoltaic devices. Furthermore, the PBClT/ITIC blend film showed a π-π stacking distance of 3.85 Å, which was very close to that of its non-chlorine analog blend film with a distance of approximately 3.74 Å. Based on this result, the introduction of multiple chlorine atoms on the conjugated side chains not only adjusted the energy level of the low-band-gap polymer through the electron withdrawing ability of the chlorine atoms but also subtly avoided obvious morphological changes that could result from strong steric hindrance in the main chain of the polymers. The PBClT/ITIC-based PSCs exhibited a maximum PCE of 8.46% with a V oc of 1.01 V, which is an increase in the PCE of approximately 22% compared to the PTB7-Th-based device based on our parallel experiments.« less

Discovery of thalicthuberine as a novel antimitotic agent from nature that disrupts microtubule dynamics and induces apoptosis in prostate cancer cells

PubMed Central

2018-01-01

ABSTRACT We report for the first time the mechanism of action of the natural product thalicthuberine (TH) in prostate and cervical cancer cells. TH induced a strong accumulation of LNCaP cells in mitosis, severe mitotic spindle defects, and asymmetric cell divisions, ultimately leading to mitotic catastrophe accompanied by cell death through apoptosis. However, unlike microtubule-binding drugs (vinblastine and paclitaxel), TH did not directly inhibit tubulin polymerization when tested in a cell-free system, whereas it reduced cellular microtubule polymer mass in LNCaP cells. This suggests that TH indirectly targets microtubule dynamics through inhibition of a critical regulator or tubulin-associated protein. Furthermore, TH is not a major substrate for P-glycoprotein (Pgp), which is responsible for multidrug resistance in numerous cancers, providing a rationale to further study TH in cancers with Pgp-mediated treatment resistance. The identification of TH's molecular target in future studies will be of great value to the development of TH as potential treatment of multidrug-resistant tumors. PMID:28749250

Structure-Stability Relationships of Polymers Based on Thermogravimetric Analysis Data. Part 1. Polyaliphatics, Polyalicyclics, Spiro Polymers and Phenylene-R-Polymers

DTIC Science & Technology

1974-12-01

Polymerization 13 9. Polymers with Bridged Ring Systems 14 10. Spiro Polymers 14 11. Polyphenylene s 16 12. Phenol - Formaldehyde Resins 17 13. Polyphenylene... Formaldehyde Resins A wide variety of phenol- formaldehyde resins , cured with various curing agents, has been evaluated. The Tdec’s (N 2 ), which...415 0 570 415 540C 2- 410 0 -CHI - 0- c-Ci.f-CCH = 1-eC.- 390 540 0 (Phenol- Formaldehyde Resins ) -CVH- (aliph.) 390 / F_ 535 0 - CHL" (epoxy

[Biodegradable catheters for fistula prevention in hypospadias. Experimental preliminary study].

PubMed

Ramos, J L; Aldazabal, P; Zuza, E; Sarasúa, J R; Arrieta, A; Villanueva, A; Eizaguirre, I

2013-04-01

Continuous technical innovations are not enough to resolve the high incidence of fistula after hypospadias repair. A urethral catheter-tutor made of reabsorbable polymeric biomaterial (RPB) which could be left in situ long enough could reduce the complications. To investigate in an animal model differents RPB to be used in urology. CRL Wistar rats, males, divided into 5 equal groups according to the used polymers: polylactide; lactic-coprolactone copolymer; lactic-glycolic copolymer; simulated; control silicones. Three individuals were sacrificed per group at 4th, 10th and 16th week. In all animals (exceptuating the simulated group), biomaterial was fixed to the bladder wall bylaparotomy. Animals remained in individual housing and kept under daily control of hematuria during the first 15 days and weekly weight and urine control for pH and lactate. After being slaughtered, remaining polymer was collected for chemical analysis and bladder tissue for hystologic study. There was no mortality, hematuria nor other clinical signs. The bladder wall showed a mild foreign body reaction. The values of lactate and pH in urine did not reach toxic levels. Lactic-glycolic was totally reabsorbed by the 10th week and had the lowest degree of calcification. Polylactide and lactic-coprolactone remained intact. The model of urinary bladder has proven useful for studying the degradation of bioresorbable polymers. The analyzed polymers have spent long time to be reabsorbed, so we will have to study new others.

Polymer and Surface Science in Europe, Israel, and Egypt: Some Observations,

DTIC Science & Technology

1981-11-25

BASCOM N UNCLASSIFIED ONRL-9 6-8 AL EndE~EE~hE 2.2 11 . 111 111111.5 1 . 4 ! 1 4 f ADA൑ 8 5 9 R-6-81 COND LDOW OFFICE Of, N A L POLYMER AND SURFACE...FORM 1 . REPORT NUMBER 12. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Polymer and...support or as participation in "sandwich" study programs. Under the sandwich system the student interrupts his studies after 1 to 2 yrs to spend 6 to 12

Department of Defense Weapon System Acquisition Policy: A System Dynamics Model and Analysis.

DTIC Science & Technology

1982-09-01

dimensionless) PRPRD = Perceived Pressure for R&D (dimensionless) PU - Programs in Progress (programs) RPRD - Raw Pressure for R&D (dimensionless) TDPP - Time...ECAP) TH9 Pressure Ra Pressure_.- for Acquisition ( TDPP ) TH25 4for Acquisition (DPFAO) TH22D (DPPFAO) TH21 US Intelligence \\ - 7 Delay Time / efense...DIBP, DPPFAQ. K) TH22 A CPPFAG.K=DLINF3(RPFAG.KTCPP) TH23 A CPFAQ.K=MAX (DIBPCPPFAQ.K) TH24 C TDPP =12 TH25 C TCPP-24 TH26 CPFAQ Congressional Pressure

TGF-Beta Gene Polymorphisms in Food Allergic versus Non-Food Allergic Eosinophilic Esophagitis

DTIC Science & Technology

2012-10-01

successful EoE therapy in 60-98% of subjects. Indeed, th e majority of children with EoE have specific IgE to foods but they often continue to ingest...sensitized children with EoE and the TGFb1 genes. W e hypothesize that in EoE there is a gene polymorphism (TGFb1) environment (food) interaction that...esophageal stricture form ation is an im portant complication of remodeling in EoE (6-12% of children ; 33% of adults), identif ying genetic polym orphisms in

Synthesis of polymer nanostructures with conductance switching properties

DOEpatents

Su, Kai; Nuraje, Nurxat; Zhang, Lingzhi; Matsui, Hiroshi; Yang, Nan Loh

2015-03-03

The present invention is directed to crystalline organic polymer nanoparticles comprising a conductive organic polymer; wherein the crystalline organic polymer nanoparticles have a size of from 10 nm to 200 nm and exhibits two current-voltage states: (1) a high resistance current-voltage state, and (2) a low resistance current-voltage state, wherein when a first positive threshold voltage (V.sub.th1) or higher positive voltage, or a second negative threshold voltage (V.sub.th2) or higher negative voltage is applied to the nanoparticle, the nanoparticle exhibits the low-resistance current-voltage state, and when a voltage less positive than the first positive threshold voltage or a voltage less negative than the second negative threshold voltage is applied to the nanoparticle, the nanoparticle exhibits the high-resistance current-voltage state. The present invention is also directed methods of manufacturing the nanoparticles using novel interfacial oxidative polymerization techniques.

Stable T-bet(+)GATA-3(+) Th1/Th2 hybrid cells arise in vivo, can develop directly from naive precursors, and limit immunopathologic inflammation.

PubMed

Peine, Michael; Rausch, Sebastian; Helmstetter, Caroline; Fröhlich, Anja; Hegazy, Ahmed N; Kühl, Anja A; Grevelding, Christoph G; Höfer, Thomas; Hartmann, Susanne; Löhning, Max

2013-01-01

Differentiated T helper (Th) cell lineages are thought to emerge from alternative cell fate decisions. However, recent studies indicated that differentiated Th cells can adopt mixed phenotypes during secondary immunological challenges. Here we show that natural primary immune responses against parasites generate bifunctional Th1 and Th2 hybrid cells that co-express the lineage-specifying transcription factors T-bet and GATA-3 and co-produce Th1 and Th2 cytokines. The integration of Th1-promoting interferon (IFN)-γ and interleukin (IL)-12 signals together with Th2-favoring IL-4 signals commits naive Th cells directly and homogeneously to the hybrid Th1/2 phenotype. Specifically, IFN-γ signals are essential for T-bet(+)GATA-3(+) cells to develop in vitro and in vivo by breaking the dominance of IL-4 over IL-12 signals. The hybrid Th1/2 phenotype is stably maintained in memory cells in vivo for months. It resists reprogramming into classic Th1 or Th2 cells by Th1- or Th2-promoting stimuli, which rather induce quantitative modulations of the combined Th1 and Th2 programs without abolishing either. The hybrid phenotype is associated with intermediate manifestations of both Th1 and Th2 cell properties. Consistently, hybrid Th1/2 cells support inflammatory type-1 and type-2 immune responses but cause less immunopathology than Th1 and Th2 cells, respectively. Thus, we propose the self-limitation of effector T cells based on the stable cell-intrinsic balance of two opposing differentiation programs as a novel concept of how the immune system can prevent excessive inflammation.

Polymer Chemistry

NASA Technical Reports Server (NTRS)

Williams, Martha; Roberson, Luke; Caraccio, Anne

2010-01-01

This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

Ultrasonography and clinical outcome comparison of extracorporeal shock wave therapy and corticosteroid injections for chronic plantar fasciitis: A randomized controlled trial

PubMed Central

Lai, Ta-Wei; Ma, Hsiao-Li; Lee, Meng-Shiunn; Chen, Po-Ming; Ku, Ming-Chou

2018-01-01

Objectives: Extracorporeal shockwave therapy (ESWT) and corticosteroid injection (CSI) are treatment options for plantar fasciitis. Their clinical outcome comparison remains a debate. Also, the thickness changes of the plantar fascia on objective evaluation under the medium energy ESWT and CSI therapy are elusive. Methods: A total of 97 patients with chronic plantar fasciitis were enrolled in the randomized prospective trial. Forty-seven patients received extracorporeal shock wave therapy (ESWT), and fifty patients received corticosteroid injection (CSI). The thickness of the plantar fascia was evaluated respectively before ESWT and CSI, and at the 4th and 12th week after ESWT and CSI by ultrasonography. Pain level and clinical outcomes were recorded using visual analogue scale (VAS) and 100-points scoring systems. Correlation analysis was performed between the thickness change and clinical outcome. Results: Under ultrasonography, we observed more increase of plantar fascia thickness of ESWT group than CSI group at 4th week (p=0.048). VAS of plantar fasciitis patients receiving ESWT was lower than those who received corticosteroid injection (0.001 and p<0.001, at 4th and 12th week). On the assessment of 100-points scoring systems, the pain level of patients with ESWT was lower than those with CSI at the 12th week (p<0.001). On the other hand, the increase of plantar fascia thickness at 4th week was positively correlated with the decrease of VAS score at 12th week follow-up (R=0.302, P=0.039). Conclusions: At 4th week after treatment, the thickness of plantar fascia increased. Then it decreased gradually, but not to the baseline at 12th week. On the pain level outcome at 12th week, extracorporeal shockwave therapy (ESWT) was more efficient than corticosteroid injection (CSI) on chronic plantar fasciitis. The more change of plantar fascia after ESWT, the more efficient on clinical outcome. PMID:29504578

Ultrasonography and clinical outcome comparison of extracorporeal shock wave therapy and corticosteroid injections for chronic plantar fasciitis: A randomized controlled trial.

PubMed

Lai, Ta-Wei; Ma, Hsiao-Li; Lee, Meng-Shiunn; Chen, Po-Ming; Ku, Ming-Chou

2018-03-01

Extracorporeal shockwave therapy (ESWT) and corticosteroid injection (CSI) are treatment options for plantar fasciitis. Their clinical outcome comparison remains a debate. Also, the thickness changes of the plantar fascia on objective evaluation under the medium energy ESWT and CSI therapy are elusive. A total of 97 patients with chronic plantar fasciitis were enrolled in the randomized prospective trial. Forty-seven patients received extracorporeal shock wave therapy (ESWT), and fifty patients received corticosteroid injection (CSI). The thickness of the plantar fascia was evaluated respectively before ESWT and CSI, and at the 4 th and 12 th week after ESWT and CSI by ultrasonography. Pain level and clinical outcomes were recorded using visual analogue scale (VAS) and 100-points scoring systems. Correlation analysis was performed between the thickness change and clinical outcome. Under ultrasonography, we observed more increase of plantar fascia thickness of ESWT group than CSI group at 4 th week (p=0.048). VAS of plantar fasciitis patients receiving ESWT was lower than those who received corticosteroid injection (0.001 and p⟨0.001, at 4 th and 12 th week). On the assessment of 100-points scoring systems, the pain level of patients with ESWT was lower than those with CSI at the 12 th week (p⟨0.001). On the other hand, the increase of plantar fascia thickness at 4 th week was positively correlated with the decrease of VAS score at 12 th week follow-up (R=0.302, P=0.039). At 4 th week after treatment, the thickness of plantar fascia increased. Then it decreased gradually, but not to the baseline at 12 th week. On the pain level outcome at 12 th week, extracorporeal shockwave therapy (ESWT) was more efficient than corticosteroid injection (CSI) on chronic plantar fasciitis. The more change of plantar fascia after ESWT, the more efficient on clinical outcome.

Bubble Dynamics in Polymer Solutions Undergoing Shear.

DTIC Science & Technology

1985-04-01

cavitation bubble in water has been established as the fundamental theoretical approach to understanding this phenomenon. LA_ Laser -induced...cavitation inception. 1-2 Polymer effects on cavity appearance. 2-1 Spherical laser -induced bubble dynamics. 2-2 Vapor cavity jet formation. 2-3 Bubble...distilled water. 2-6B Nonspherical bubble dynamics in dilute polymer. 3-1 Closed-loop hydraulic cavitation tunnel. 3-2 Laser system optical components. 3-3

Carbon nanoparticle doped micro-patternable nano-composites for wearable sensing applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Khosla, Ajit

2017-04-01

This talk focuses on preparation, characterization and micropatterning of electrically conducting KETJENBLACK carbon black nanoparticle (80 nm-diameter) doped Polydimethylsiloxane (PDMS) by employing extrusion mixing. Previously, we had reported fabrication of various micropatternable nanocomposites for wearable sensing applications vis solvent assisted ultrasonic mixing technique[1-16] . Extrusion mixing has an advantage as no organic solvents are used and homogenous dispersion of carbon nanoparticles is observed, which is confirmed by SEM analysis. The developed nanocomposite can be micropatterened using standard microfabrication techniques. It is also observed that percolation threshold occurs at 0.51 wt% of carbon nanoparticles in polymer matrix. Examples of developed nano-composites for wearable sensing applications for precision medicine will also be discussed. References: 1.http://summit.sfu.ca/item/12017 A. Khosla. Micropatternable multifunctional nanocomposite polymers for flexible soft MEMS applications. Diss. Applied Science: School of Engineering Science, 2011. 2. A. Khosla ; B. L. Gray; Fabrication of multiwalled carbon nanotube polydimethylsiloxne nanocomposite polymer flexible microelectrodes for microfluidics and MEMS. Proc. SPIE 7642, Electroactive Polymer Actuators and Devices (EAPAD) 2010, 76421V (April 09, 2010); doi:10.1117/12.847292. 3. Ang Li ; Ajit Khosla ; Connie Drewbrook ; Bonnie L. Gray; Fabrication and testing of thermally responsive hydrogel-based actuators using polymer heater elements for flexible microvalves. Proc. SPIE 7929, Microfluidics, BioMEMS, and Medical Microsystems IX, 79290G (February 14, 2011); doi:10.1117/12.873197. 4. Khosla, A. and Gray, B. L. (2010), Preparation, Micro-Patterning and Electrical Characterization of Functionalized Carbon-Nanotube Polydimethylsiloxane Nanocomposite Polymer. Macromol. Symp., 297: 210-218. doi:10.1002/masy.200900165 5. A. Khosla ; D. Hilbich ; C. Drewbrook ; D. Chung ; B. L. Gray; Large scale micropatterning of multi-walled carbon nanotube/polydimethylsiloxane nanocomposite polymer on highly flexible 12×24 inch substrates. Proc. SPIE 7926, Micromachining and Microfabrication Process Technology XVI, 79260L (February 15, 2011); doi:10.1117/12.876738. 6. A. Khosla, and Bonnie L. Gray. "(Invited) Micropatternable Multifunctional Nanocomposite Polymers for Flexible Soft NEMS and MEMS Applications." ECS Transactions 45.3 (2012): 477-494. doi: 10.1149/1.3700913 7. Khosla, Ajit. "Nanoparticle-doped electrically-conducting polymers for flexible nano-micro Systems." Electrochemical Society Interface 21.3-4 (2012): 67-70. 8. Ajit Khosla; Smart garments in chronic disease management: progress and challenges. Proc. SPIE 8548, Nanosystems in Engineering and Medicine, 85482O (October 24, 2012); doi:10.1117/12.979667. 9. D. Chung ; A. Khosla ; B. L. Gray; Screen printable flexible conductive nanocomposite polymer with applications to wearable sensors. Proc. SPIE 9060, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2014, 90600U (April 16, 2014); doi:10.1117/12.2046548. 10. Daehan Chung ; Sam Seyfollahi ; Ajit Khosla ; Bonnie Gray ; Ash Parameswaran ; Ramani Ramaseshan ; Kirpal Kohli; Initial experiments with flexible conductive electrodes for potential applications in cancer tissue screening. Proc. SPIE 7929, Microfluidics, BioMEMS, and Medical Microsystems IX, 79290Z (February 14, 2011); doi:10.1117/12.875563. 11. A. Khosla ; B. L. Gray; New technologies for large-scale micropatterning of functional nanocomposite polymers. Proc. SPIE 8344, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2012, 83440W (April 26, 2012); doi:10.1117/12.915178. 12. A. Khosla, B.L. Gray, Preparation, characterization and micromolding of multi-walled carbon nanotube polydimethylsiloxane conducting nanocomposite polymer, Materials Letters, Volume 63, Issues 13-14, 31 May 2009, Pages 1203-1206, ISSN 0167-577X, http://dx.doi.org/10.1016/j.matlet.2009.02.043. 13. Giassa, M., Khosla, A., Gray, B. et al. J Electron Test (2010) 26: 139. doi:10.1007/s10836-009-5125-3 14.Ozhikandathil, Jayan, Ajit Khosla, and Muthukumaran Packirisamy. "Electrically Conducting PDMS Nanocomposite Using In Situ Reduction of Gold Nanostructures and Mechanical Stimulation of Carbon Nanotubes and Silver Nanoparticles." ECS Journal of Solid State Science and Technology 4.10 (2015): S3048-S3052. doi:10.1149/2.0091510jss 15. Kassegne, Sam, Maria Vomero, Roberto Gavuglio, Mieko Hirabayashi, Emre Özyilmaz, Sebastien Nguyen, Jesus Rodriguez, Eda Özyilmaz, Pieter van Niekerk, and Ajit Khosla. "Electrical impedance, electrochemistry, mechanical stiffness, and hardness tunability in glassy carbon MEMS μECoG electrodes." Microelectronic Engineering 133 (2015): 36-44. 16. A. Khosla ; B. L. Gray; Fabrication and properties of conductive micromoldable thermosetting polymer for electronic routing in highly flexible microfluidic systems. Proc. SPIE 7593, Microfluidics, BioMEMS, and Medical Microsystems VIII, 759314 (February 17, 2010); doi:10.1117/12.840911.

Highlights of 10th plasma chemistry meeting

NASA Technical Reports Server (NTRS)

Kitamura, K.; Hashimoto, H.; Hozumi, K.

1981-01-01

The chemical structure is given of a film formed by plasma polymerization from pyridine monomers. The film has a hydrophilic chemical structure, its molecular weight is 900, and the molecular system is C55H50N10O3. The electrical characteristics of a plasma polymerized film are described. The film has good insulating properties and was successfully applied as video disc coating. Etching resistance properties make it possible to use the film as a resist in etching. The characteristics of plasma polymer formed from monomers containing tetramethyltin are discussed. The polymer is in film form, displays good adhesiveness, is similar to UV film UV 35 in light absorption and is highly insulating.

International SAMPE Symposium and Exhibition, 35th, Anaheim, CA, Apr. 2-5, 1990, Proceedings. Books 1 2

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

Janicki, G.; Bailey, V.; Schjelderup, H.

The present conference discusses topics in the fields of ultralightweight structures, producibility of thermoplastic composites, innovation in sandwich structures, composite failure processes, toughened materials, metal-matrix composites, advanced materials for future naval systems, thermoplastic polymers, automated composites manufacturers, advanced adhesives, emerging processes for aerospace component fabrication, and modified resin systems. Also discussed are matrix behavior for damage tolerance, composite materials repair, testing for damage tolerance, composite strength analyses, materials workplace health and safety, cost-conscious composites, bismaleimide systems, and issues facing advanced composite materials suppliers.

Water-Compatible Polymer Concrete Materials for use in Rapid Repair Systems for Airport Runways

DTIC Science & Technology

1981-03-01

resin systems, resorcinol phenol- formaldehyde (RPF), urea - formaldehyde (UF), melamine - formaldehyde (MF), and furfuryl alcohol (FA), were selected for...type polymer systems. Phenol- formaldehyde (PF), melamine - formaldehyde (MF), urea -formalde- hyde (UF), and furfuryl alcohol (FA) monomers contain OH and...1-1.5) (1-2) Urea - formaldehyde NH2 CONH2 - HCHO Liquid 7150 (1.0) (1.5-2.5) Melamine - formaldehyde NH2 C:NC(NH2 ):NC(N’H2

Influence of Crosslinking on the Mechanical Properties of High TG Polymers

DTIC Science & Technology

1976-07-01

with UV light has been previously described (48). In brief, benzoin was used as the initiator (0.3 percent), acrylic acid anhydride (AAA) as the labile...1.9 1.0 1.8 0.8 1.7 110 4M (th)x 10 1.0 2.0 1.0 2.0 1.0 2.0 4M- -(E) x 10 0.9 1.2 0.9 1.3 0.7 1.2 1.7 EA: 100 ml Benzoin : 0.4 g 22 Table 3. PEA...L) x 10 4.1 9.0 4.0 10.0 2.4 - - c (wg)x 104 5.7 8.7 3.5 8.4 2.7 - - M-c (E) x 10 1.2 2.1 1.0 2.1 0.8 1.0 1.3 EA: 100 ml Benzoin : 0.4 g Table 4. PEA

Networks 90: Polymer Networks Group Meeting (10th) and IUPAC international Symposium on Polymer Networks (10th) Held in Jerusalem on 20-25 May 1990. Programme and Abstracts

DTIC Science & Technology

1990-05-25

INCLUDING ORIENTATIONAL INTERACTIONS BETWEEN CHAIN SEGMENTS B. Deloche, E.T. Samulski (France, USA) CHAIN SEGMENT ORDERING IN STRAINED BIMODAL P-2 PDMS...theory of elastomers is difficult because it requires a detailed study of many body interactions . A theory of elasticity must address the following: (1...a Kirchhoff matrix which describes the connectivity of the network (Kc) or the linear chains (Ku). The nonbonded interactions are handled with the

Laminated Object Manufacturing-Based Design Ceramic Matrix Composites

DTIC Science & Technology

2001-04-01

components for DoD applications. Program goals included the development of (1) a new LOM based design methodology for CMC, (2) optimized preceramic polymer ...3.1.1-20 3.1.1-12 Detail of LOM Composites Forming System w/ glass fiber/ polymer laminate................ 3.1.1-21 3.1.1-13...such as polymer matrix composites have faced similar barriers to implementation. These barriers have been overcome through the development of suitable

Universal size properties of a star-ring polymer structure in disordered environments

NASA Astrophysics Data System (ADS)

Haydukivska, K.; Blavatska, V.

2018-03-01

We consider the complex polymer system, consisting of a ring polymer connected to the f1-branched starlike structure, in a good solvent in the presence of structural inhomogeneities. In particular cases f1=1 and f1=2 , such a system restores the synthesized tadpole-shaped polystyrenes [Doi et al., Macromolecules 46, 1075 (2013), 10.1021/ma302511j]. We assume that structural defects are correlated at large distances x according to a power law x-a. Applying the direct polymer renormalization approach, we evaluate the universal size characteristics such as the ratio of the radii of gyration of star-ring and star topologies, and compare the effective sizes of single arms in complex structures and isolated polymers of the same total molecular weight. The nontrivial impact of disorder on these quantities is analyzed.

Processing and Dynamic Failure Characterization of Novel Impact Absorbing Transparent Interpenetrating Polymer Networks (t-IPN)

DTIC Science & Technology

2014-02-01

samples were placed into the oven for the same curing treatment as before. The scanning electron microscope (SEM) photo in Figure 19 shows a typical...Interpenetrating Polymer Networks with Polyurethane and Methacrylate-based Polymers,’ S. A . Bird , PhD Dissertation, Department of Polymer and Fiber Engineering...Jajam, H. V. Tippur, S. A . Bird , and M. L. Auad, Proceedings of the 50th SES Annual Technical Meeting and ASME-AMD Summer Meeting, Providence, RI

Extending the lanthanide-terephthalate system: Isolation of an unprecedented Tb(III)-based coordination polymer with high potential porosity and luminescence properties

NASA Astrophysics Data System (ADS)

Le Natur, François; Calvez, Guillaume; Freslon, Stéphane; Daiguebonne, Carole; Bernot, Kevin; Guillou, Olivier

2015-04-01

A novel coordination polymer with chemical formula {[Tb(bdc)1.5(H2O)]ṡ(DMF)(H2O)}∞ (1) has been synthesized by reaction between 1,4-benzene-dicarboxylic acid (H2bdc) and di-cationic hexanuclear entity [Tb6O(OH)8(NO3)6(H2O)12]2+ in an ethylene glycol (EG)/N,N-dimethylformamide (DMF) mixture. This compound has been obtained as single crystals by slow evaporation in air at room temperature. If the hexanuclear entity is destroyed during the reaction, the coordination polymer that is obtained is original and presents promising potential micro-porosity and luminescent properties. It crystallizes in the monoclinic system, space group C12/c1 (No. 15) with the cell parameters a = 23.7540(1) Å, b = 10.5390(4) Å, c = 19.7580(3) Å, β = 125.8100(1)° and Z = 8.

Solid-State Sensor and Actuator Workshop Held at Hilton Head Island, South Carolina on June 6-9, 1988

DTIC Science & Technology

1988-01-01

Stable Photoresist’, Polym. Figure 71 Eng. Sci. 26 1101(1986) 2) W.E. Feely, " Microplastic Structures, SPIE 631 48(1986) Figure 12 15 A Miniature...unhulbt k- beanils than i ntrini fl t iilins. polys5tilicin sea led cavities fo r re’.i t rain~d uc cr arrays," in Technical Die I IFF IFDN1 p 2;3. I...the The experience with thermal sealing indicates that glass. Sufficient charge transfer occurs to allow th, sea . of glass to metl form when tile metal

Anti-IL-23 receptor monoclonal antibody prevents CD4+ T cell-mediated colitis in association with decreased systemic Th1 and Th17 responses.

PubMed

Imamura, Emiko; Taguchi, Katsunari; Sasaki-Iwaoka, Haruna; Kubo, Satoshi; Furukawa, Shigetada; Morokata, Tatsuaki

2018-04-05

Experimental colitis studies, including T cell-mediated colitis, indicate that IL-23 rather than IL-12 orchestrates intestinal inflammation in inflammatory bowel disease (IBD). Previous studies have identified the roles of IL-12 and IL-23 using mice deficient for their specific subunits, p35 and p19, respectively. However, these studies do not completely reflect the difference in roles between IL-12 and IL-23, especially since the discovery of novel IL-12 family cytokines, which also include p35 or p19 subunits. Here, to clarify the contribution of IL-12 and IL-23 in T cell-mediated colitis, we compared the efficacy of a monoclonal antibody (mAb) to an IL-23-specific receptor subunit with that of an anti-IL-12/23p40 mAb in a naive CD4 + T cell transfer model of experimental colitis, which is associated with enhanced Th1 and Th17 responses. Both antibodies almost completely prevented the development of colitis and showed reduced associated histological changes, including mucosal hyperplasia, infiltration of inflammatory cells and loss of goblet cells. The anti-IL-23 receptor mAb inhibited not only the systemic Th17-response but also the Th1-response, both of which were up-regulated in this model. These results suggest that IL-23, but not IL-12, signaling is critical for the development of colitis. Blockade of IL-23 signaling is a promising therapeutic approach for IBD. Copyright © 2018 Elsevier B.V. All rights reserved.

Feasibility and Biocompatibility of 3D-Printed Photopolymerized and Laser Sintered Polymers for Neuronal, Myogenic, and Hepatic Cell Types.

PubMed

Rimington, Rowan P; Capel, Andrew J; Player, Darren J; Bibb, Richard J; Christie, Steven D R; Lewis, Mark P

2018-06-13

The integration of additive manufacturing (AM) technology within biological systems holds significant potential, specifically when refining the methods utilized for the creation of in vitro models. Therefore, examination of cellular interaction with the physical/physicochemical properties of 3D-printed polymers is critically important. In this work, skeletal muscle (C 2 C 12 ), neuronal (SH-SY5Y) and hepatic (HepG2) cell lines are utilized to ascertain critical evidence of cellular behavior in response to 3D-printed candidate polymers: Clear-FL (stereolithography, SL), PA-12 (laser sintering, LS), and VeroClear (PolyJet). This research outlines initial critical evidence for a framework of polymer/AM process selection when 3D printing biologically receptive scaffolds, derived from industry standard, commercially available AM instrumentation. C 2 C 12 , SH-SY5Y, and HepG2 cells favor LS polymer PA-12 for applications in which cellular adherence is necessitated. However, cell type specific responses are evident when cultured in the chemical leachate of photopolymers (Clear-FL and VeroClear). With the increasing prevalence of 3D-printed biointerfaces, the development of rigorous cell type specific biocompatibility data is imperative. Supplementing the currently limited database of functional 3D-printed biomaterials affords the opportunity for experiment-specific AM process and polymer selection, dependent on biological application and intricacy of design features required. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Wagyu- versus Angus-sired calves on feedlot performance, carcass characteristics, and tenderness.

PubMed

Radunz, A E; Loerch, S C; Lowe, G D; Fluharty, F L; Zerby, H N

2009-09-01

Wagyu-sired (n = 20) and Angus-sired (n = 19) steers and heifers were used to compare the effects of sire breed on feedlot performance, carcass characteristics, and meat tenderness. Calves were weaned at 138 +/- 5 d of age and individually fed a finishing diet consisting of 65% whole corn, 20% protein/vitamin/mineral supplement, and 15% corn silage on a DM basis. Heifers and steers were slaughtered at 535 and 560 kg of BW, respectively. Carcasses were ribbed between the 12th and 13th (USDA grading system) and the 6th and 7th ribs (Japanese grading system) to measure fat thickness, LM area (LMA), and intramuscular fat (IMF). Two steaks were removed from the 12th rib location and aged for 72 h and 14 d to determine Warner-Bratzler shear force and cooking loss. Sire breed x sex interactions were not significant (P > 0.05). Angus-sired calves had greater (P < 0.05) ADG and DMI than Wagyu. Wagyu-sired calves had improved (P < 0.05) feed efficiency than Angus. Sire breed did not affect (P > 0.20) HCW, 12th-rib fat, or USDA yield grade. Carcasses of Wagyu had greater (P = 0.0001) marbling scores at the 12th rib than those of Angus (770.9 vs. 597.3 +/- 41.01, respectively). Carcasses of Wagyu also had greater (P < 0.02) 12th-rib IMF and 6th-rib IMF than Angus, resulting in a greater proportion of carcasses grading Prime (65.0 vs. 21.1%; P = 0.006). Carcasses from Wagyu tended (P = 0.08) to have greater LMA at the 12th rib, whereas Angus carcasses had greater (P < 0.05) LMA at the 6th rib. Steaks from Angus and Wagyu had similar (P > 0.50) tenderness at aging times of 72 h and 14 d. Cooking loss was greater (P < 0.01) for Angus than Wagyu steaks at 72 h and 14 d. Using Wagyu sires vs. Angus sires on British-based commercial cows combined with early weaning management strategies has the potential to produce a product with greater marbling, but is unlikely to significantly enhance tenderness.

Flexible, highly efficient all-polymer solar cells

PubMed Central

Kim, Taesu; Kim, Jae-Han; Kang, Tae Eui; Lee, Changyeon; Kang, Hyunbum; Shin, Minkwan; Wang, Cheng; Ma, Biwu; Jeong, Unyong; Kim, Taek-Soo; Kim, Bumjoon J.

2015-01-01

All-polymer solar cells have shown great potential as flexible and portable power generators. These devices should offer good mechanical endurance with high power-conversion efficiency for viability in commercial applications. In this work, we develop highly efficient and mechanically robust all-polymer solar cells that are based on the PBDTTTPD polymer donor and the P(NDI2HD-T) polymer acceptor. These systems exhibit high power-conversion efficiency of 6.64%. Also, the proposed all-polymer solar cells have even better performance than the control polymer-fullerene devices with phenyl-C61-butyric acid methyl ester (PCBM) as the electron acceptor (6.12%). More importantly, our all-polymer solar cells exhibit dramatically enhanced strength and flexibility compared with polymer/PCBM devices, with 60- and 470-fold improvements in elongation at break and toughness, respectively. The superior mechanical properties of all-polymer solar cells afford greater tolerance to severe deformations than conventional polymer-fullerene solar cells, making them much better candidates for applications in flexible and portable devices. PMID:26449658

Research notes : polymer concrete bridge deck overlays : Deschutes River Bridge (Biggs), Maupin Bridge (Maupin) : final report.

DOT National Transportation Integrated Search

1995-07-01

This report documents the construction and performance of two thin polymer concrete (with polyester/styrene resins) bridge deck overlays. The overlays were constructed in Biggs and Maupin, Oregon in June 1993. Construction of the overlays was less th...

Composite membranes from photochemical synthesis of ultrathin polymer films

NASA Astrophysics Data System (ADS)

Liu, Chao; Martin, Charles R.

1991-07-01

THERE has recently been a resurgence of interest in synthetic membranes and membrane-based processes1-12. This is motivated by a wide variety of technological applications, such as chemical separations1-7, bioreactors and sensors8,9, energy conversion10,11 and drug-delivery systems12. Many of these technologies require the ability to prepare extremely thin, defect-free synthetic (generally polymeric) films, which are supported on microporous supports to form composite membranes. Here we describe a method for producing composite membranes of this sort that incorporate high-quality polymer films less than 50-nm thick. The method involves interfacial photopolymerization of a thin polymer film on the surface of the microporous substrate. We have been able to use this technique to synthesize a variety of functionalized ultrathin films based on electroactive, photoactive and ion-exchange polymers. We demonstrate the method here with composite membranes that show exceptional gas-transport properties.

Nasal delivery of chitosan-coated poly(lactide-co-glycolide)-encapsulated honeybee (Apis mellifera) venom promotes Th 1-specific systemic and local intestinal immune responses in weaned pigs.

PubMed

Lee, Jin-A; Kim, Yun-Mi; Kim, Tae-Hoon; Lee, Sang-Ho; Lee, Cho-A; Cho, Cheong-Weon; Jeon, Jong-Woon; Park, Jin-Kyu; Kim, Sang-Ki; Jung, Bock-Gie; Lee, Bong-Joo

2016-10-01

Nasal delivery is a convenient and acceptable route for drug administration, and has been shown to elicit a much more potent local and systemic response compared with other drug delivery routes. We previously demonstrated that rectal administration of poly(lactide-co-glycolide)-encapsulated honeybee venom (P-HBV) could enhance systemic Th 1-specific immune responses. We therefore synthesized chitosan-coated P-HBV (CP-HBV) and then evaluated the immune-boosting efficacy of nasally administered CP-HBV on systemic and local intestinal immunity compared with non-chitosan-coated P-HBV. The nasally delivered CP-HBV effectively enhanced Th 1-specific responses, eliciting a significant increase in the CD3(+)CD4(+)CD8(-) Th cell population, lymphocyte proliferation capacity, and expression of Th 1 cytokines (IFN-γ, IL-12, and IL-2) in peripheral blood mononuclear cells. Furthermore, these immune-boosting effects persisted up to 21days post CP-HBV administration. Nasal administration of CP-HBV also led to an increase of not only the CD4(+) Th 1 and IFN-γ secreting CD4(+) Th 1 cell population but also Th 1-specific cytokines and transcription factors, including IL-12, IFN-γ, STAT4, and T-bet, in isolated mononuclear cells from the spleen and ileum. Copyright © 2016 Elsevier B.V. All rights reserved.

Methylhydridopolysilazane and its Pyrolytic Conversion to Si3N4/SiC Ceramics

DTIC Science & Technology

1993-04-20

development of inorganic and organometallic polymers as preceramic materials for the synthesis of silicon carbide ( SiC ) and silicon nitride (Si 3N 4...disproportionation in the pyrolysis of preceramic polymers . The lack of a -50 ppm resonance in the CP-MAS NMR spectra of the MHPS systems is 12...1992); Chem. Abstr. 1992, 116, 220226g. 6. (a) Semen, J.; Loop, J.G., "A Preceramic Polymer Route to Molded SiC Ceramic Parts," Ceram. Eng. Sci. Proc

Enhanced Delivery of Plasmid Encoding Interleukin-12 Gene by Diethylene Triamine Penta-Acetic Acid (DTPA)-Conjugated PEI Nanoparticles.

PubMed

Dehshahri, Ali; Sadeghpour, Hossein; Keykhaee, Maryam; Khalvati, Bahman; Sheikhsaran, Fatemeh

2016-05-01

Recombinant therapeutic proteins have been considered as an efficient category of medications used for the treatment of various diseases. Despite their effectiveness, there are some reports on the systemic adverse effects of recombinant therapeutic proteins limiting their wide clinical applications. Among different cytokines used for cancer immunotherapy, interleukin-12 (IL-12) has shown great ability as a powerful antitumor and antiangiogenic agent. However, significant toxic reactions following the systemic administration of IL-12 have led researchers to seek for alternative approaches such as the delivery and local expression of the IL-12 gene inside the tumor tissues. In order to transfer the plasmid encoding IL-12 gene, the most extensively investigated polycationic polymer, polyethylenimine (PEI), was modified by diethylene triamine penta-acetic acid (DTPA) to modulate the hydrophobic-hydrophilic balance of the polymer as well as its toxicity. DTPA-conjugated PEI derivatives were able to form complexes in the size range around 100-180 nm with great condensation ability and protection of the plasmid against enzymatic degradation. The highest gene transfer ability was achieved by the DTPA-conjugated PEI at the conjugation degree of 0.1 % where the level of IL-12 production increased up to twofold compared with that of the unmodified PEI. Results of the present study demonstrated that modulation of the surface positive charge of PEI along with the improvement of the polymer hydrophobic balance could be considered as a successful strategy to develop safe and powerful nanocarriers.

12 CFR 261a.5 - Request for access to records.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Federal Reserve System, 20th Street and Constitution Avenue, NW., Washington, DC 20551. (2) If you request... 261a.5 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE... writing to the Inspector General, Board of Governors of the Federal Reserve System, 20th Street and...

Fasciola hepatica reinfection potentiates a mixed Th1/Th2/Th17/Treg response and correlates with the clinical phenotypes of anemia

PubMed Central

Perez-Crespo, Ignacio; Chillón-Marinas, Carlos; Khoubbane, Messaoud; Quesada, Carla; Reguera-Gomez, Marta; Mas-Coma, Santiago; Fresno, Manuel; Gironès, Núria

2017-01-01

Background Fascioliasis is a severe zoonotic disease of worldwide extension caused by liver flukes. In human fascioliasis hyperendemic areas, reinfection and chronicity are the norm and anemia is the main sign. Herein, the profile of the Th1/Th2/Th17/Treg expression levels is analyzed after reinfection, correlating them with their corresponding hematological biomarkers of morbidity. Methodology/Principal findings The experimental design reproduces the usual reinfection/chronicity conditions in human fascioliasis endemic areas and included Fasciola hepatica primo-infected Wistar rats (PI) and rats reinfected at 8 weeks (R8), and at 12 weeks (R12), and negative control rats. In a cross-sectional study, the expression of the genes associated with Th1 (Ifng, Il12a, Il12b, Nos2), Th2 (Il4, Arg1), Treg (Foxp3, Il10, Tgfb, Ebi3), and Th17 (Il17) in the spleen and thymus was analyzed. After 20 weeks of primary infection, PI did not present significant changes in the expression of those genes when compared to non-infected rats (NI), but an increase of Il4, Arg1 and Ifng mRNA in the spleen was observed in R12, suggesting the existence of an active mixed Th1/Th2 systemic immune response in reinfection. Foxp3, Il10, Tgfb and Ebi3 levels increased in the spleen in R12 when compared to NI and PI, indicating that the Treg gene expression levels are potentiated in chronic phase reinfection. Il17 gene expression levels in R12 in the spleen increased when compared to NI, PI and R8. Gene expression levels of Il10 in the thymus increased when compared to NI and PI in R12. Ifng expression levels in the thymus increased in all reinfected rats, but not in PI. The clinical phenotype was determined by the fluke burden, the rat body weight and the hemogram. Multivariate mathematical models were built to describe the Th1/Th2/Th17/Treg expression levels and the clinical phenotype. In reinfection, two phenotypic patterns were detected: i) one which includes only increased splenic Ifng expression levels but no Treg expression, correlating with severe anemia; ii) another which includes increased splenic Ifng and Treg expression levels, correlating with a less severe anemia. Conclusions/Significance In animals with established F. hepatica infection a huge increase in the immune response occurs, being a mixed Th2/Treg associated gene expression together with an expression of Ifng. Interestingly, a Th17 associated gene expression is also observed. Reinfection in the chronic phase is able to activate a mixed immune response (Th1/Th2/Th17/Treg) against F. hepatica but T and B proliferation to mitogens is strongly suppressed in all infected rats vs control in the advanced chronic phase independently of reinfection The systemic immune response is different in each group, suggesting that suppression is mediated by different mechanisms in each case. Immune suppression could be due to the parasite in PI and R8 rats and the induction of suppressive cells such as Treg in R12. This is the first study to provide fundamental insight into the immune profile in fascioliasis reinfection and its relation with the clinical phenotypes of anemia. PMID:28362822

Multidetector thermal field-flow fractionation as a novel tool for the microstructure separation of polyisoprene and polybutadiene.

PubMed

Greyling, Guilaume; Pasch, Harald

2014-11-01

For the first time, it is demonstrated that thermal field-flow fractionation (ThFFF) is an efficient tool for the fractionation of polyisoprene (PI) and polybutadiene (PB) with regard to molecular microstructure. ThFFF analysis of 1,4- and 3,4-PI as well as 1,4- and 1,2-PB samples in tetrahydrofuran (THF), THF/cyclohexane, and cyclohexane reveals that isomers of the same polymer family having similar molar masses exhibit different Soret coefficients depending on microstructure for each solvent. The separation according to microstructure is found to be based on the cooperative influence of the normal and the thermal diffusion coefficient. Of the three solvents, cyclohexane has the greatest influence on the fractionation of the isomers. In order to determine the distribution of isomeric structures in the PI and PB samples, the samples are fractionated by ThFFF in cyclohexane and subsequently analyzed by (1) H NMR. The isomeric distributions determined from NMR data correlate well with ThFFF retention data of the samples and thus further highlight the unique fractionating capabilities of ThFFF. The interplay of the normal and thermal diffusion coefficients that are influenced by temperature and the mobile phase opens the way to highly selective fractionations without the drawbacks of column-based separation methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of polymer charge on the shear yield stress of silica aggregated with adsorbed cationic polymers.

PubMed

Zhou, Ying; Yu, Hai; Wanless, Erica J; Jameson, Graeme J; Franks, George V

2009-08-15

Flocs were produced by adding three cationic polymers (10% charge density, 3.0x10(5) g/mol molecular weight; 40% charge density, 1.1x10(5) g/mol molecular weight; and 100% charge density, 1.2x10(5) g/mol molecular weight) to 90 nm diameter silica particles. The shear yield stresses of the consolidated sediment beds from settled and centrifuged flocs were determined via the vane technique. The polymer charge density plays an important role in influencing the shear yield stresses of sediment beds. The shear yield stresses of sediment beds from flocs induced by the 10% charged polymer were observed to increase with an increase in polymer dose, initial solid concentration and background electrolyte concentration at all volume fractions. In comparison, polymer dose has a marginal effect on the shear yield stresses of sediment beds from flocs induced by the 40% and 100% charged polymers. The shear yield stresses of sediments from flocs induced by the 40% charged polymer are independent of salt concentration whereas the addition of salt decreases the shear yield stresses of sediments from flocs induced by the 100% charged polymer. When flocculated at the optimum dose for each polymer (12 mg/g silica for the 10% charged polymer at 0.03 M NaCl, 12 mg/g for 40% and 2 mg/g for 100%), shear yield stress increases as polymer charge increases. The effects observed are related to the flocculation mechanism (bridging, patch attraction or charge neutralisation) and the magnitude of the adhesive force. Comparison of shear and compressive yield stresses show that the network is only slightly weaker in shear than in compression. This is different than many other systems (mainly salt and pH coagulation) which have shear yield stress much less than compressive yield stress. The existing models relating the power law exponent of the volume fraction dependence of the shear yield stress to the network fractal structure are not satisfactory to predict all the experimental behaviour.

Immobilization of Trametes hirsuta laccase into poly(3,4-ethylenedioxythiophene) and polyaniline polymer-matrices

NASA Astrophysics Data System (ADS)

Wang, Xiaoju; Sjöberg-Eerola, Pia; Immonen, Kirsi; Bobacka, Johan; Bergelin, Mikael

The immobilization of Trametes hirsuta laccase (ThL) in the poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) matrices was carried out in order to study the catalytic effect of ThL in different biocathode structures in a biofuel cell application. By using 2,2‧-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a mediator compound, the immobilized ThL in both polymer matrices, exhibited catalytic activity for the reduction of oxygen into water. The amount of ThL was adjustable in the PEDOT matrix by controlling the working parameters, such as the charge density used in the electropolymerization of EDOT monomer and the ThL concentration used in the electropolymerization electrolyte. In the PEDOT biocathode structure, the utilization of porous material as the PEDOT supporting template was studied in order to improve the current density generated per unit area/volume. Reticulated vitreous carbon foam (RVC foam) was chosen as the PEDOT supporting template material and the biocathodes were manufactured by in situ entrapment of ThL into PEDOT films polymerized on the RVC foam. These biocathodes possessed a high cathodic open circuit potential and produced a large current density, reaching 1 mA cm -3 at 0.45 V when 19.5 μg ml -1 of ThL was used in the electrolyte. The performance of these biocathodes was extremely sensitive to variations in pH and the optimal working pH was around 4.2. The biocathode reserved 80%, 50%, and 30% of the catalytic activity after storage in a +4 °C buffer solution for 1 day, 1 week, and 1 month, respectively. The PANI matrix was prepared in a form of printable ink where ThL was in situ entrapped in the PANI matrix during the laccase activated polymerization of aniline using a chemical batch reactor method. Different amounts of the ThL-containing printable PANI ink were then applied on carbon paper and the performance of the ink was subsequently electrochemically characterized. In this way, not only two different polymer matrices, but also two different matrix manufacturing procedures could be compared.

35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

NASA Astrophysics Data System (ADS)

Son, In-Hyuk; Shin, Woo-Cheol; Lee, Yong-Kul; Lee, Sung-Chul; Ahn, Jin-Gu; Han, Sang-Il; kweon, Ho-Jin; Kim, Ju-Yong; Kim, Moon-Chan; Park, Jun-Yong

A polymer electrolyte membrane fuel cell (PEMFC) system is developed to power a notebook computer. The system consists of a compact methanol-reforming system with a CO preferential oxidation unit, a 16-cell PEMFC stack, and a control unit for the management of the system with a d.c.-d.c. converter. The compact fuel-processor system (260 cm 3) generates about 1.2 L min -1 of reformate, which corresponds to 35 We, with a low CO concentration (<30 ppm, typically 0 ppm), and is thus proven to be capable of being targetted at notebook computers.

International Conference on Electronic Processes in Organic Materials (6th) Held in Gurzuf, Crimea, Ukraine, on September 25-29, 2006

DTIC Science & Technology

2006-09-29

MEH-PPV and blends MEH-PPV/fullerene derivative to investigate the charge transfer process . Microstructure - properties correlation of blends polymer...liquid crystals 4. Nonlinear properties of organic structures and composites 5. Electronic processes within polymer composites 6. Nanostructures. Polymer...P.A.Kondratenko, Yu.M.Lopatkin, TN.Sakun. SPECTROSCOPIC PROPERTIES AND PROCESSES OF PHOTODISSOCIATION OF DYES ....... 32 D.-Q. Feng, D. Wisbey, Y. Ta4 Ya. B

Effect of strain rate on mechanical properties of melt-processed soy flour composite filler and styrene-butadiene blends

USDA-ARS?s Scientific Manuscript database

Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dispersion of soy flour with styrene-butadiene rubber latex, dried, and cryogenically ground into powders. Upon crosslinking, th...

Ber-H2 (CD30) Immunohistochemical Staining of Human Fetal Tissues

PubMed Central

2005-01-01

OBJECTIVE: CD30 antigen has long been considered to be restricted to the tumour cells of Hodgkin's disease and of anaplastic large cell lymphoma as well as to T and B activated lymphocytes. It is now apparent that the range of normal and neoplastic cells, which may express CD30 antigen, is much wider than was at first thought. In order to gain insight into the physiological function of CD30 antigen, we studied the distribution of its expression in the tissues of fetuses from week 8th to week 16th. MATERIALS AND METHODS: We investigated the immunohistochemical expression of CD30 antigen in paraffin-embedded tissue samples representing all systems from 30 fetuses after therapeutic abortion at 8th to 10th and 12th to 16th week of gestation, respectively, using the monoclonal antibody Ber-H2. RESULTS: Our results demonstrated that CD30 is expressed early in human fetal development (8th to 10th week of gestation) in several fetal tissues derived from all three germ layers (gastrointestinal tract, special glands of the postpharyngeal foregut, urinary, musculoskeletal, reproductive, nervous, endocrine systems), with the exception of the skin and hematolymphoid system (thymus), in which the antigen is expressed later on (10th week onwards). Expression of CD30 was restricted to the hematolymphoid system in the 12-16 weeks of gestation. No expression of the marker was observed in the respiratory and cardiovascular systems during the entire period examined. CONCLUSIONS: CD30 antigen is of importance in cell development, and proliferation. It is also pathway-related to terminal differentiation in many fetal tissues and organs. PMID:16244703

Soy matrix drug delivery systems obtained by melt-processing techniques.

PubMed

Vaz, Cláudia M; van Doeveren, Patrick F N M; Reis, Rui L; Cunha, António M

2003-01-01

The aim of this study was to develop new soy protein drug delivery matrix systems by melt-processing techniques, namely, extrusion and injection moulding. The soy matrix systems with an encapsulated drug (theophylline, TH) were previously compounded by extrusion performed at two different pH values, (i) pH 4 (SIpDtp) and (ii) pH 7 (SIDtp), and further injection-moulded into a desired shape. During the extrusion process the matrixes SIDtp were also cross-linked with glyoxal (0.6X-SIDtp) and reinforced with a bioactive filler, hydroxylapatite (SI-HADtp). The obtained mouldings were used to study the drug-release mechanisms from the plastic soy-TH matrixes. In an isotonic saline solution (ISS) buffered at pH 5.0 (200 mM acetate buffer), the resulting release kinetics could be described using the Fick's second law of diffusion. Because the diffusion coefficients were found to be constant and the boundary conditions to be stationary, these systems are drug-diffusion controlled. Conversely, the dominant phenomena in an isotonic saline solution buffered at pH 7.4 (200 mM Tris/HCl buffer) are more complex. In fact, because of the higher polymer solubility, the resulting matrix is time-variant. So, the drug release is affected by swelling, drug diffusion, and polymer dissolution, being faster when compared to ISS-200 mM acetate buffer, pH 5.0. The changes in the formulation composition affecting the correspondent release rates were also investigated. At pH 7.4, increasing the cross-linking degree of the polymer matrix (via reaction with glyoxal or heat treatment) or decreasing the net charge (extruding at pH near its isoelectric point) led to lower release rates. The incorporation of ceramic filler caused the opposite effect. Because of the low solubility of the matrix at pH 5.0, no significant variations were detected with variations in the selected formulations. These systems, based on a nonstandard protein-based material, seem to be very promising to be used as carriers for drug delivery.

Documentation of Assessment Instrumentation--The NORC/CRESST 12th Grade Science Assessment, Item Databases, and Test Booklets. Project 2.6: Analytic Models To Monitor Status & Progress of Learning & Performance & Their Antecedents: The School Science Assessment Project.

ERIC Educational Resources Information Center

Bock, H. Darrell

The hardware and software system used to create the National Opinion Research Center/Center for Research on Evaluation, Standards, and Student Testing (NORC/CRESST) item databases and test booklets for the 12th-grade science assessment are described. A general description of the capabilities of the system is given, with some specific information…

(Networking + Integrating) * (Systems + Society). Proceedings of the Annual Canadian Conference of Information Science (12th, Toronto, Ontario, May 14-16, 1984) = (Reseaux + Integration) * (Systemes + Societe). Comptes rendus de la conference annuelle Canadienne des sciences de l'information (12th, Toronto, Ontario, 14-16 mai, 1984).

ERIC Educational Resources Information Center

Canadian Association for Information Science, Ottawa (Ontario).

Seventeen papers from the 1984 annual conference of the Canadian Association for Information Science (CAIS) are presented in four broad topic areas. The first group, which focuses on changing roles in information access, includes the keynote address by Charles Meadow, "Integrating Access to Information Utilities: Promises, Problems, and…

European scientific notes. Volume 38. Number 1. Monthly publication

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

Shaffer, L.E.

1984-01-01

Topics include: Gender-mixed Crews on Dutch Combat Ships; Max-Planck-Institute for Psycholinguistics; Cancer Therapy with Magnetism; 9th European Underwater Biomedical Society Convention; International Center for Genetic Engineering and Biotechnology; Biotechnological Route to Polyphenylene; 2nd Romania-US Seminar on Polymer Chemistry; Statistical Climatology; A Code for Generating Dynamic Models of Robots; Fifth Generation Computing Systems; New Data Logger; Erosion by Liquid and Solid Impact, ELSI VI; Physical Chemistry of the Solid State -- Metals and alloys; NATO Buys a New Oceanographic Research Vessel; Oceanexpo/Oceantropigues 1984; Progress in Development of Wave Energy to Generate Electricity; IAPSO Symposia and Oceanography at the 18th IUGG; Newmore » Decision Support System; High Energy Channeling Research in Switzerland; Muon-Catalyzed Fusion; 2nd International Symposium on Acoustic Remote Sensing of the Atmosphere and Ocean; and Support of Science Research by the British Military.« less

Thermal Relaxation Processes and Stability in Poled Electro-Optic Polymers

DTIC Science & Technology

1994-06-30

34, Gordon Research Conference on Dielectric Phenomena, Holderness School, NH July 31-August 5, 1994. 2. K.D. Singer, R. Dureiko, J. Khaydarov , and R...Fuerst, "Relaxation in Poled Electro- optic Polymers", 4th Iketani Conference, Hawaii, May 17-20, 1994. 3. J.H. Andrews, J.D.V. Khaydarov , and K.D. Singer...Dureiko, J. Khaydarov , and R. Fuerst, "Relaxation Phenomena in Poled Electro-Optic Polymers", Proc. Mat. Res. Soc. 328, 499 (1994). 5. R.A. Fuerst, "Thermal

4TH Mediterranean Workshop and Tropical Meeting "Novel Optical Materials and Applications" NOMA 99.

DTIC Science & Technology

1999-07-19

If excitons have anharmonicity, the combination of large oscillator strength and the anharmonicity leads to large optical nonlinearity. Numerous...almost all NLO-polymers have a large optical loss compared with passive WG polymers. In these hybrid structures, only an active part for signal...quasi- phase matching based on chirality. I .::;~~~~~~~~a -: . .: 1 2 :: : , : •:•: :.?- ?i•;-•’’’::: .. AZOBENZENE POLYMERS FOR OPTICAL INFORMATION

Synthesis and Characterisation of Biocompatible Polymer-Conjugated Magnetic Beads for Enhancement Stability of Urease.

PubMed

Doğaç, Yasemin Ispirli; Teke, Mustafa

2016-04-01

We reported natural polymer-conjugated magnetic featured urease systems for removal of urea effectively. The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70 °C), pH stability (4.0-9.0), operational stability (0-250 min), reusability (18 times) and storage stability (24 weeks) were studied for characterisation of the urease-encapsulated biocompatible polymer-conjugated magnetic beads. Also, the surface groups and chemical structure of the magnetic beads were determined by using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The all urease-encapsulated magnetic beads protected their stability of 30-45 % relative activity at 70 °C. A significant increase was observed at their pH stability compared with the free urease for both acidic and alkaline medium. Besides this, their repeatability activity were approximately 100 % during 4(th) run. They showed residual activity of 50 % after 16 weeks. The importance of this work is enhancement stability of immobilised urease by biocompatible polymer-conjugated magnetic beads for the industrial application based on removal of urea.

A novel dextran polymer hydrogel local antimicrobial therapy in dogs: A pilot study

PubMed Central

Reed, Travis P.; Thomas, Leslie A.; Weeren, F. Robert; Ruth, Jeffrey D.; Anders, Brendan B.

2016-01-01

Our purpose was to evaluate physical, laboratory, and/or radiographic abnormalities associated with a novel dextran polymer hydrogel local antimicrobial agent impregnated with amikacin and clindamycin in dogs having tibial plateau leveling osteotomy implants removed due to suspected surgical site infection. A total of 28 client-owned dogs were enrolled and 20 completed the study. Routine plate explantation and bacterial cultures were performed and the polymer hydrogel was applied to the surgery site. No systemic antimicrobials were used after surgery. Serum biochemistry, hematology, urinalysis, physical examinations, and radiographs were monitored before surgery and up to 12 wk after surgery. Sixteen of the 20 dogs (80%) had a positive bacterial culture, 44% of which were methicillin resistant. There were no significant alterations of laboratory values, physical examination, or radiographs to indicate adverse reactions to the polymer hydrogel. There were no signs of inflammation or infection in any patient at the 12-week postoperative recheck. PMID:26834272

A pH/enzyme-responsive polymer film consisting of Eudragit FS 30 D and arabinoxylane as a potential material formulation for colon-specific drug delivery system.

PubMed

Rabito, Mirela Fulgencio; Reis, Adriano Valim; Freitas, Adonilson dos Reis; Tambourgi, Elias Basile; Cavalcanti, Osvaldo Albuquerque

2012-01-01

Polymer film based on pH-dependent Eudragit FS 30 D acrylic polymer in association with arabinoxylane, a polysaccharide issued from gum psyllium, was produced by way of solvent casting. Physical-chemical characterization of the polymer film samples was performed by means of thermogravimetry (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Furthermore, water-equilibrium swelling index (I(s)) and weight loss of the films in KCl buffer solution of pH 1.2, in KH(2)PO(4) buffer solution of pH 5.0, or in KH(2)PO(4) buffer solution of pH 5.0 consisting of 4% enzyme Pectinex 3X-L (w/v) were also carried out for the film characterization. No chemical interactions between the Eudragit FS 30 D and the arabinoxylane polymer chains were evidenced, thus suggesting that the film-forming polymer structure was obtained from a physical mixture of both polymers. The arabinoxylane-loader films showed a more pronounced weight loss after their immersion in buffer solution containing enzyme Pectinex 3X-L. The introduction of the arabinoxylane makes the film more susceptible to undergo an enzymatic degradation. This meant that the enzyme-dependent propriety issued from the arabinoxylane has been imprinted into the film formulation. This type of polymer film is an interesting system for applications in colon-specific drug delivery system.

Initiated chemical vapor deposition polymers for high peak-power laser targets

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

Baxamusa, Salmaan H.; Lepro, Xavier; Lee, Tom

2016-12-05

Here, we report two examples of initiated chemical vapor deposition (iCVD) polymers being developed for use in laser targets for high peak-power laser systems. First, we show that iCVD poly(divinylbenzene) is more photo-oxidatively stable than the plasma polymers currently used in laser targets. Thick layers (10–12 μm) of this highly crosslinked polymer can be deposited with near-zero intrinsic film stress. Second, we show that iCVD epoxy polymers can be crosslinked after deposition to form thin adhesive layers for assembling precision laser targets. The bondlines can be made as thin as ~ 1 μm, approximately a factor of 2 thinner thanmore » achievable using viscous resin-based adhesives. These bonds can withstand downstream coining and stamping processes.« less

External electro-optic sampling utilizing a poled polymer asymmetric Fabry Perot cavity as an electro-optical probe tip

NASA Astrophysics Data System (ADS)

Chen, Kaixin; Zhang, Hongbo; Zhang, Daming; Yang, Han; Yi, Maobin

2002-09-01

External electro-optic sampling utilizing a poled polymer asymmetry Fabry-Perot cavity as electro-optic probe tip has been demonstrated. Electro-optical polymer spin coated on the high-reflectivity mirror (HRM) was corona poled. Thus, an asymmetric F-P cavity was formed based on the different reflectivity of the polymer and HRM and it converted the phase modulation that originates from electro-optic effect of the poled polymer to amplitude modulation, so only one laser beam is needed in this system. The principle of the sampling was analyzed by multiple reflection and index ellipsoid methods. A 1.2 GHz microwave signal propagating on coplanar waveguide transmission line was sampled, and the voltage sensitivity about 0.5 mV/ Hz was obtained.

Characterization and Clinical Implication of Th1/Th2/Th17 Cytokines Produced from Three-Dimensionally Cultured Tumor Tissues Resected from Breast Cancer Patients

PubMed Central

Kiyomi, Anna; Makita, Masujiro; Ozeki, Tomoko; Li, Na; Satomura, Aiko; Tanaka, Sachiko; Onda, Kenji; Sugiyama, Kentaro; Iwase, Takuji; Hirano, Toshihiko

2015-01-01

OBJECTIVES: Several cytokines secreted from breast cancer tissues are suggested to be related to disease prognosis. We examined Th1/Th2/Th17 cytokines produced from three-dimensionally cultured breast cancer tissues and related them with patient clinical profiles. METHODS: 21 tumor tissues and 9 normal tissues surgically resected from breast cancer patients were cultured in thermoreversible gelatin polymer–containing medium. Tissue growth and Th1/Th2/Th17 cytokine concentrations in the culture medium were analyzed and were related with hormone receptor expressions and patient clinical profiles. RESULTS: IL-6 and IL-10 were expressed highly in culture medium of both cancer and normal tissues. However, IFN-γ, TNF-α, IL-2, and IL-17A were not detected in the supernatant of the three-dimensionally cultured normal mammary gland and are seemed to be specific to breast cancer tissues. The growth abilities of hormone receptor–negative cancer tissues were significantly higher than those of receptor-positive tissues (P = 0.0383). Cancer tissues of stage ≥ IIB patients expressed significantly higher TNF-α levels as compared with those of patients with stage < IIB (P = 0.0096). CONCLUSIONS: The tumor tissues resected from breast cancer patients can grow in the three-dimensional thermoreversible gelatin polymer culture system and produce Th1/Th2/Th17 cytokines. Hormone receptor–positive cancer tissues showed less growth ability. TNF-α is suggested to be a biomarker for the cancer stage. PMID:26310378

Materials for Concentrator Photovoltaic Systems: Optical Properties and Solar Radiation Durability

NASA Astrophysics Data System (ADS)

French, R. H.; Rodríguez-Parada, J. M.; Yang, M. K.; Lemon, M. F.; Romano, E. C.; Boydell, P.

2010-10-01

Concentrator photovoltaic (CPV) systems are designed to operate over a wide range of solar concentrations, from low concentrations of ˜1 to 12 Suns to medium concentrations in the range from 12 to 200 Suns, to high concentration CPV systems going up to 2000 Suns. Many transparent optical materials are used for a wide variety of functions ranging from refractive and reflective optics to homogenizers, encapsulants and even thermal management. The classes of materials used also span a wide spectrum from hydrocarbon polymers (HCP) and fluoropolymers (FP) to silicon containing polymers and polyimides (PI). The optical properties of these materials are essential to the optical behavior of the system. At the same time radiation durability of these materials under the extremely wide range of solar concentrations is a critical performance requirement for the required lifetime of a CPV system. As part of our research on materials for CPV we are evaluating the optical properties and solar radiation durability of various polymeric materials to define the optimum material combinations for various CPV systems.

Responsive Boronic Acid-Decorated (Co)polymers: From Glucose Sensors to Autonomous Drug Delivery.

PubMed

Vancoillie, Gertjan; Hoogenboom, Richard

2016-10-19

Boronic acid-containing (co)polymers have fascinated researchers for decades, garnering attention for their unique responsiveness toward 1,2- and 1,3-diols, including saccharides and nucleotides. The applications of materials that exert this property are manifold including sensing, but also self-regulated drug delivery systems through responsive membranes or micelles. In this review, some of the main applications of boronic acid containing (co)polymers are discussed focusing on the role of the boronic acid group in the response mechanism. We hope that this summary, which highlights the importance and potential of boronic acid-decorated polymeric materials, will inspire further research within this interesting field of responsive polymers and polymeric materials.

Responsive Boronic Acid-Decorated (Co)polymers: From Glucose Sensors to Autonomous Drug Delivery

PubMed Central

Vancoillie, Gertjan; Hoogenboom, Richard

2016-01-01

Boronic acid-containing (co)polymers have fascinated researchers for decades, garnering attention for their unique responsiveness toward 1,2- and 1,3-diols, including saccharides and nucleotides. The applications of materials that exert this property are manifold including sensing, but also self-regulated drug delivery systems through responsive membranes or micelles. In this review, some of the main applications of boronic acid containing (co)polymers are discussed focusing on the role of the boronic acid group in the response mechanism. We hope that this summary, which highlights the importance and potential of boronic acid-decorated polymeric materials, will inspire further research within this interesting field of responsive polymers and polymeric materials. PMID:27775572

COUPLING THE ALKALINE-SURFACTANT-POLYMER TECHNOLOGY AND THE GELATION TECHNOLOGY TO MAXIMIZE OIL PRODUCTION

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

Malcolm Pitts; Jie Qi; Dan Wilson

2005-04-01

Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A priormore » fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent alkaline-surfactant-polymer injected solution were observed. Aluminum citrate-polyacrylamide, resorcinol-formaldehyde, and the silicate-polyacrylamide gel systems did not produce significant incremental oil in linear corefloods. Both flowing and rigid flowing chromium acetate-polyacrylamide gels and the xanthan gum-chromium acetate gel system produced incremental oil with the rigid flowing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. None of the gels tested appeared to alter alkaline-surfactant-polymer solution oil recovery. Total waterflood plus chemical flood oil recovery sequence recoveries were all similar.« less

Mechanical Systems. Competency Statements/Objectives and Reference Guide.

ERIC Educational Resources Information Center

North Carolina State Dept. of Public Instruction, Raleigh. Div. of Vocational Education.

This curriculum guide provides competency statements/objectives for an 11th- to 12th-grade trade and industrial education course in mechanical systems. The first half of the guide consists of competency statements for the 53 units of the curriculum. Each competency statement consists of a terminal objective and specific objectives for each unit,…

12 CFR 261a.5 - Request for access to record.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Reserve System, 20th and Constitution Avenue NW., Washington, DC 20551. (2) A request by a current Board... Constitution Avenue NW., Washington, DC 20551. (3) A request by a current Board employee for information other... Information Office, Board of Governors of the Federal Reserve System, 20th and Constitution Avenue NW...

Multifunctional Nanofibers Comprised of Conducting and Ferroelectric Polymer Composites

DTIC Science & Technology

2015-08-04

8th Ibero-American Congress on Sensors-Ibersensor2012, Isla Verde , Puerto Rico, October 2012. 2. Devices and sensors based on PVDF-TrFE/SWCNT’s...composites, M. Bonilla, I. Ramos and N.J. Pinto, 8th Ibero-American Congress on Sensors-Ibersensor2012, Isla Verde , Puerto Rico, October 2012. 3

Marshalling Corporate Resources for Public and K-12 Technical Education Outreach and Engagement

NASA Astrophysics Data System (ADS)

Wynne, James

2011-03-01

In 1988, the Education Task Force of the Business Roundtable recommended that American corporations invest in pre-college education. Prior to that date, corporate investment was targeted at higher education. IBM and other corporations responded by encouraging their employees and their corporate philanthropic organizations to develop programs aimed at enhancing pre-college education. The IBM TJ Watson Research Center initiated a Local Education Outreach program, active for these past 23 years, that marshals the resources of our science-rich institution to enhance STEM education in our local schools. We have broad and deep partnerships between the Research Center and local school districts, including New York City. We have just completed our 19th consecutive year of Family Science Saturdays, which brings 4th and 5th grade children, along with their parents, to our Research Center for hands-on workshops in topics like States of Matter, Polymer Science, Kitchen Chemistry, and Sound and Light. The workshops are staffed by IBM volunteers, assisted by local high school student ``Peer Teachers.'' Since 1990, the IBM Corporation has joined with a coalition of other companies, professional engineering societies, and government agencies to sponsor the annual Engineers Week (EWeek) campaign of technical education outreach, serving as Corporate Chair in 1992, 2001, and 2008. In recent years, we have annually recruited around 5000 IBM volunteers to reach out to more than 200,000 K-12 students in order to increase their awareness and appreciation of technical careers and encourage them to continue their studies of STEM (science, technology, engineering, and mathematics). The speaker, who helped found the APS Forum on Education (FED) and served as FED Councillor for 8 years, will review these and other programs for Public and K-12 Technical Education Outreach and Engagement.

CERTAIN SPECIFIC FEATURES OF THE HIGHER NERVOUS ACTIVITY OF FULLY GROWN ANIMALS IRRADIATED ANTENATALLY WITH IONIZING RADIATION. I. THE INFLUENCE OF IONIZING RADIATION ON THE OFFSPRING

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

Piontkovskii, I.A.

1958-09-01

Irradiation of pregnant female aniamals and women with ionizing radiation may cause the appearance of a variety of congenital deformities in the offspring and may interfere with their postnatal development. L. Hicks points out the particular sensitivity of the nervous system of the embryo to ionizing radiation. Thus irradiation of rats on the 9th, 11th, 12th, and 13th days of prenatal development may cause, in addition to somatic deformities, anencephaly (on the 9th day), hydrocephaly (on the 11th day), microcephaly (on the 12th13th day), failure of development of the subcortical structures, the corpora callosa and so on. The influence ofmore » ionizing radiation on the nervous system during antenatal irradiation has been studied mainly morphologically. There are no indications in the literature of the state of the higher nervous activity of fully grown animals exposed at various periods of their antenatal development to the action of ionizing radiation. The effect of ionizing radiation, applied in various doses and at different stages of embryonic development, on the state of the higher nervous activity of animals was studied. (auth)« less

40 CFR 721.10072 - Benzene, 1,1′-methylenebis[4-isocyanato-, polymer with benzenedicarboxylic acid, butyl dialkyl...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-isocyanato-, polymer with benzenedicarboxylic acid, butyl dialkyl ester, poly[oxy(methyl-1,2-ethanediyl)], .alpha.-hydro-.omega.-hydroxy-, oxirane, alkyl-, polymer with oxirane, ether with propanepolyol and...-isocyanato-, polymer with benzenedicarboxylic acid, butyl dialkyl ester, poly[oxy(methyl-1,2-ethanediyl...

Investigation of micro-injection molding based on longitudinal ultrasonic vibration core.

PubMed

Qiu, Zhongjun; Yang, Xue; Zheng, Hui; Gao, Shan; Fang, Fengzhou

2015-10-01

An ultrasound-assisted micro-injection molding method is proposed to improve the rheological behavior of the polymer melt radically, and a micro-injection molding system based on a longitudinal ultrasonic vibration core is developed and employed in the micro-injection molding process of Fresnel lenses. The verification experiments show that the filling mold area of the polymer melt is increased by 6.08% to 19.12%, and the symmetric deviation of the Fresnel lens is improved 15.62% on average. This method improved the filling performance and replication quality of the polymer melt in the injection molding process effectively.

High thermal conductivity in electrostatically engineered amorphous polymers

PubMed Central

Shanker, Apoorv; Li, Chen; Kim, Gun-Ho; Gidley, David; Pipe, Kevin P.; Kim, Jinsang

2017-01-01

High thermal conductivity is critical for many applications of polymers (for example, packaging of light-emitting diodes), in which heat must be dissipated efficiently to maintain the functionality and reliability of a system. Whereas uniaxially extended chain morphology has been shown to significantly enhance thermal conductivity in individual polymer chains and fibers, bulk polymers with coiled and entangled chains have low thermal conductivities (0.1 to 0.4 W m−1 K−1). We demonstrate that systematic ionization of a weak anionic polyelectrolyte, polyacrylic acid (PAA), resulting in extended and stiffened polymer chains with superior packing, can significantly enhance its thermal conductivity. Cross-plane thermal conductivity in spin-cast amorphous films steadily grows with PAA degree of ionization, reaching up to ~1.2 W m−1 K−1, which is on par with that of glass and about six times higher than that of most amorphous polymers, suggesting a new unexplored molecular engineering strategy to achieve high thermal conductivities in amorphous bulk polymers. PMID:28782022

Nanoparticle-assisted high photoconductive gain in polymer/fullerene matrix

PubMed Central

Chen, Hsiang-Yu; Lo, Michael K. F.; Yang, Guanwen; Monbouquette, Harold G.; Yang, Yang

2014-01-01

Polymer/inorganic nanocrystal composites1–10 offer an attractive means to combine the merits of organic and inorganic materials into novel electronic and photonic systems. However, many applications of these composites are limited by the solubility11 and distribution of nanocrystals (NCs) in polymer matrices. Here, a high photoconductive gain has been achieved by blending cadmium telluride (CdTe) nanoparticles (NPs) into a polymer/fullerene matrix followed by a solvent annealing12 process. The NP surface capping ligand, N-phenyl-N’-methyldithiocarbamate, renders the NPs highly soluble in the polymer blend thereby enabling high nanocrystal loadings. An external quantum efficiency (EQE) as high as ~8000% (at 350nm) is reached at −4.5V. Hole-dominant devices coupled with AFM images are studied to uncover the probable mechanism. We observe a higher concentration of CdTe NPs is located near the cathode/polymer interface. These NPs with trapped electrons assist hole injection into the polymer under reverse bias, which contributes to greater than 100% EQE. PMID:18772915

Searching for low percolation thresholds within amphiphilic polymer membranes: The effect of side chain branching

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

Dorenbos, G., E-mail: dorenbos@ny.thn.ne.jp

Percolation thresholds for solvent diffusion within hydrated model polymeric membranes are derived from dissipative particle dynamics in combination with Monte Carlo (MC) tracer diffusion calculations. The polymer backbones are composed of hydrophobic A beads to which at regular intervals Y-shaped side chains are attached. Each side chain is composed of eight A beads and contains two identical branches that are each terminated with a pendant hydrophilic C bead. Four types of side chains are considered for which the two branches (each represented as [C], [AC], [AAC], or [AAAC]) are splitting off from the 8th, 6th, 4th, or 2nd A bead,more » respectively. Water diffusion through the phase separated water containing pore networks is deduced from MC tracer diffusion calculations. The percolation threshold for the architectures containing the [C] and [AC] branches is at a water volume fraction of ∼0.07 and 0.08, respectively. These are much lower than those derived earlier for linear architectures of various side chain length and side chain distributions. Control of side chain architecture is thus a very interesting design parameter to decrease the percolation threshold for solvent and proton transports within flexible amphiphilic polymer membranes.« less

Consumer Education--Home Economics. Performance Objectives. Criterion Measures. Home Economics.

ERIC Educational Resources Information Center

Duval County School Board, Jacksonville, FL.

Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives for an 18-week consumer education-home economics course for 10th, 11th, and 12th grade students. Purposes listed for the course are to develop an understanding of the American market system, and how the individual affects…

15 CFR 200.107 - WWV-WWVH-WWVB broadcasts.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., and 20, MHz (WWV) and 2.5, 5, 10, and 15 MHz (WWVH); (2) standard time signals; (3) time intervals; (4...) Omega Navigation System status reports; (9) geophysical alerts; and (10) marine storm warnings. NIST... correction is “plus” 0.3 second. If the ninth, 10th, 11th, and 12th ticks are doubled, the correction is...

15 CFR 200.107 - WWV-WWVH-WWVB broadcasts.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., and 20, MHz (WWV) and 2.5, 5, 10, and 15 MHz (WWVH); (2) standard time signals; (3) time intervals; (4...) Omega Navigation System status reports; (9) geophysical alerts; and (10) marine storm warnings. NIST... correction is “plus” 0.3 second. If the ninth, 10th, 11th, and 12th ticks are doubled, the correction is...

15 CFR 200.107 - WWV-WWVH-WWVB broadcasts.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., and 20, MHz (WWV) and 2.5, 5, 10, and 15 MHz (WWVH); (2) standard time signals; (3) time intervals; (4...) Omega Navigation System status reports; (9) geophysical alerts; and (10) marine storm warnings. NIST... correction is “plus” 0.3 second. If the ninth, 10th, 11th, and 12th ticks are doubled, the correction is...

15 CFR 200.107 - WWV-WWVH-WWVB broadcasts.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., and 20, MHz (WWV) and 2.5, 5, 10, and 15 MHz (WWVH); (2) standard time signals; (3) time intervals; (4...) Omega Navigation System status reports; (9) geophysical alerts; and (10) marine storm warnings. NIST... correction is “plus” 0.3 second. If the ninth, 10th, 11th, and 12th ticks are doubled, the correction is...

15 CFR 200.107 - WWV-WWVH-WWVB broadcasts.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., and 20, MHz (WWV) and 2.5, 5, 10, and 15 MHz (WWVH); (2) standard time signals; (3) time intervals; (4...) Omega Navigation System status reports; (9) geophysical alerts; and (10) marine storm warnings. NIST... correction is “plus” 0.3 second. If the ninth, 10th, 11th, and 12th ticks are doubled, the correction is...

Thermodynamics and Phase Behavior of Miscible Polymer Blends in the Presence of Supercritical Carbon Dioxide

NASA Astrophysics Data System (ADS)

Young, Nicholas Philip

The design of environmentally-benign polymer processing techniques is an area of growing interest, motivated by the desire to reduce the emission of volatile organic compounds. Recently, supercritical carbon dioxide (scCO 2) has gained traction as a viable candidate to process polymers both as a solvent and diluent. The focus of this work was to elucidate the nature of the interactions between scCO2 and polymers in order to provide rational insight into the molecular interactions which result in the unexpected mixing thermodynamics in one such system. The work also provides insight into the nature of pairwise thermodynamic interactions in multicomponent polymer-polymer-diluent blends, and the effect of these interactions on the phase behavior of the mixture. In order to quantify the strength of interactions in the multicomponent system, the binary mixtures were characterized individually in addition to the ternary blend. Quantitative analysis of was made tractable through the use of a model miscible polymer blend containing styrene-acrylonitrile copolymer (SAN) and poly(methyl methacrylate) (dPMMA), a mixture which has been considered for a variety of practical applications. In the case of both individual polymers, scCO2 is known to behave as a diluent, wherein the extent of polymer swelling depends on both temperature and pressure. The solubility of scCO 2 in each polymer as a function of temperature and pressure was characterized elsewhere. The SAN-dPMMA blend clearly exhibited lower critical solution temperature behavior, forming homogeneous mixtures at low temperatures and phase separating at elevated temperature. These measurements allowed the determination of the Flory-Huggins interaction parameter chi23 for SAN (species 2) and dPMMA (species 3) as a function of temperature at ambient pressure, in the absence of scCO2 (species 1). Characterization of the phase behavior of the multicomponent (ternary) mixture was also carried out by SANS. An in situ SANS environment was developed to allow measurement of blend miscibility in the presence of scCO2. The pressure-temperature phase behavior of the system could be mapped by approaching the point of phase separation by spinodal decomposition through pressure increases at constant temperature. For a roughly symmetric mixture of SAN and dPMMA, the temperature at which phase separation occurred could be decreased by over 125 °C. The extent to which the phase behavior of the multicomponent system could be tuned motivated further investigation into the interactions present within the homogeneous mixtures. Analysis of the SANS results for homogeneous mixtures was undertaken using a new multicomponent formalism of the random phase approximation theory. The scattering profiles obtained from the scCO2-SAN-dPMMA system could be predicted with reasonable success. The success of the theoretical predictions was facilitated by directly employing the interactions found in the binary experiments. Exploitation of the condition of homogeneity with respect to chemical potential allowed determination of interaction parameters for scCO2-SAN and 2-dPMMA within the multicomponent mixture (chi12 and chi13, respectively). Studying this system over a large range of the supercritical regime yielded insight on the nature of interactions in the system. Near the critical point of scCO 2, chi12 and chi13 increase monotonically as a function of pressure. Conversely, at elevated temperature away from the critical point, the interaction parameters are found to go through a minimum as a pressure increases. Analysis of the critical phenomenon associated with scCO2 suggests that the observed dependence of chi12 and chi13 on pressure are related to the magnitude of scCO 2 density fluctuations and the proximity of the system to the so-called density fluctuation ridge. By tuning the system parameters of the multicomponent mixture, the phase behavior can be altered through the balance of pairwise interactions been the constituent species. The presence of scCO2 in the mixtures appears to eliminate the existence of the metastable state that epitomizes most polymer-polymer mixtures. Thus it is shown that knowledge of the individual pairwise interactions in such multicomponent mixtures can greatly influence the resulting phase behavior, and provide insight into the design of improved functional materials with decreased environmental impacts.

Expression of the IL-23/Th17 pathway in lesions of hidradenitis suppurativa.

PubMed

Schlapbach, Christoph; Hänni, Tanja; Yawalkar, Nikhil; Hunger, Robert E

2011-10-01

Hidradenitis suppurativa is a debilitating chronic disease primarily affecting intertriginous skin of the axillae, perineum, and inframammary regions. The pathogenesis of this inflammatory disease is still poorly understood. Recently, increased attention has been paid to the role of the immune system. Since the interleukin 12 (IL-12)/T helper 1 (Th1) and the IL-23/Th17 pathways are believed to be crucially involved in the pathogenesis of multiple chronic inflammatory diseases, we investigated the expression and cellular source of IL-12, IL-23, and IL-17 in hidradenitis suppurativa. Ten patients with hidradenitis suppurativa were included in the study. Tissue samples were obtained from lesional skin and compared with healthy skin as a control. Expression of IL-12, IL-23, and IL-17 was analyzed by semiquantitative real-time polymerase chain reaction and immunohistochemistry, and the cellular source of these cytokines was determined by double immunofluorescence. IL-12 and IL-23 were found to be abundantly expressed by macrophages infiltrating papillary and reticular dermis of lesional skin. In accordance with the high expression of IL-23 and its important role in the development of T helper 17 (Th17) cells, IL-17-producing T helper cells were found to distinctly infiltrate lesional dermis. The sample size was small. Our findings suggest that the IL-23/Th17 pathway is expressed in hidradenitis suppurativa and further support involvement of the immune system. Moreover, targeting the IL-12/IL-23-common subunit p40 with novel monoclonal antibodies may represent a new option for the treatment of this recalcitrant disease. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Fabrication of Polyvinylpyrrolidone Fibers by Means of Rotary Forcespinning Method

NASA Astrophysics Data System (ADS)

Andjani, D.; Sriyanti, I.; Fauzi, A.; Edikresnha, D.; Munir, M. M.; Khairurrijal

2018-05-01

Fibers made from polymer materials have been widely developed as a carrier medium of active ingredients in drug delivery systems. In this research, PVP polymer was chosen because of its wide and safe use in the medical field. The purpose of this study was to produce PVP fibers that can later be applied as a carrier of active ingredients in drug delivery systems. The rotary forcespinning (RFS) method was chosen to shorten the time of production and to overcome the limitations of electrospinning method such as the use of high voltage and dielectric solutions. The PVP solution was varied in several concentrations (8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, and 18 wt%) to achieve the best fibers morphology. The morphology and the diameter of fibers were analyzed using a digital microscope. From the microscope images, it can be shown that beaded fibers were formed when the concentration of polymer in the precursor solution was low. The number of beads decreased as the concentration of polymer increased. Beads-free fibers were fully formed at above certain polymer concentration.

Assembly of 4-, 6- and 8-connected Cd(II) pseudo-polymorphic coordination polymers: Synthesis, solvent-dependent structural variation and properties

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

Li, Zhao-Hao; Xue, Li-Ping, E-mail: lpxue@163.com; Miao, Shao-Bin

2016-08-15

The reaction of Cd(NO{sub 3}){sub 2}·4H{sub 2}O, 2,5-thiophenedicarboxylic acid (H{sub 2}tdc) and 1,2-bis(imidazol-1′-yl)methane (bimm) by modulating solvent systems yielded three highly connected pseudo-polymorphic coordination polymers based on different dinuclear [Cd{sub 2}(CO{sub 2}){sub 2}] subunits bridged by carboxylate groups. Single crystal structural analyses reveal structural variation from 4-connected 2D sql layer, 6-connected 2-fold interpenetrated 3D pcu to 8-connected 3D bcu-type network in compounds 1–3. The structural dissimilarity in the structures dependent on the coordination environments of Cd(II) ions and linking modes of mixed ligand influenced by different solvent systems during the synthesis process. Moreover, thermogravimetric and photoluminescence behaviors of 1–3 weremore » also investigated for the first time, and all the complexes emit blue luminescence in the solid state. - Graphical abstract: Key Topic. Different solvent systems modulated three Cd(II) pseudo-polymorphic coordination polymers based on thiophene-2,5-dicarboxylate and 1,2-bis(imidazol-1′-yl)methane mixed ligands. Display Omitted - Highlights: • Three solvent-dependent Cd(II) pseudo-polymorphic coordination polymers have been synthesized. • Structural variation from 4-connected 2D layer, 6-connected 2-fold interpenetrated 3D net to 8-connected 3D net. • All complexes emit blue luminescence.« less

Systemic Resistance to Powdery Mildew in Brassica napus (AACC) and Raphanus alboglabra (RRCC) by Trichoderma harzianum TH12

PubMed Central

Alkooranee, Jawadayn Talib; Yin, Yongtai; Aledan, Tamarah Raad; Jiang, Yingfen; Lu, Guangyuan; Wu, Jiangsheng; Li, Maoteng

2015-01-01

Trichoderma harzianum TH12 is a microbial pesticide for certain rapeseed diseases. The mechanism of systemic resistance induced by TH12 or its cell-free culture filtrate (CF) in Brassica napus (AACC) and Raphanus alboglabra (RRCC) to powdery mildew disease caused by ascomycete Erysiphe cruciferarum was investigated. In this study, we conducted the first large-scale global study on the cellular and molecular aspects of B. napus and R. alboglabra infected with E. cruciferarum. The histological study showed the resistance of R. alboglabra to powdery mildew disease. The growth of fungal colonies was not observed on R. alboglabra leaves at 1, 2, 4, 6, 8, and 10 days post-inoculation (dpi), whereas this was clearly observed on B. napus leaves after 6 dpi. In addition, the gene expression of six plant defense-related genes, namely, PR-1, PR-2 (a marker for SA signaling), PR-3, PDF 1.2 (a marker for JA/ET signaling), CHI620, and CHI570, for both genotypes were analyzed in the leaves of B. napus and R. alboglabra after treatment with TH12 or CF and compared with the non-treated ones. The qRT-PCR results showed that the PR-1 and PR-2 expression levels increased in E. cruciferarum-infected leaves, but decreased in the TH12-treated leaves compared with leaves treated with CF. The expression levels of PR-3 and PDF1.2 decreased in plants infected by E. cruciferarum. However, expression levels increased when the leaves were treated with TH12. For the first time, we disclosed the nature of gene expression in B. napus and R. alboglabra to explore the resistance pathways in the leaves of both genotypes infected and non-infected by powdery mildew and inoculated or non-inoculated with elicitor factors. Results suggested that R. alboglabra exhibited resistance to powdery mildew disease, and the application of T. harzianum and its CF are a useful tool to facilitate new protection methods for resist or susceptible plants. PMID:26540161

Systemic Resistance to Powdery Mildew in Brassica napus (AACC) and Raphanus alboglabra (RRCC) by Trichoderma harzianum TH12.

PubMed

Alkooranee, Jawadayn Talib; Yin, Yongtai; Aledan, Tamarah Raad; Jiang, Yingfen; Lu, Guangyuan; Wu, Jiangsheng; Li, Maoteng

2015-01-01

Trichoderma harzianum TH12 is a microbial pesticide for certain rapeseed diseases. The mechanism of systemic resistance induced by TH12 or its cell-free culture filtrate (CF) in Brassica napus (AACC) and Raphanus alboglabra (RRCC) to powdery mildew disease caused by ascomycete Erysiphe cruciferarum was investigated. In this study, we conducted the first large-scale global study on the cellular and molecular aspects of B. napus and R. alboglabra infected with E. cruciferarum. The histological study showed the resistance of R. alboglabra to powdery mildew disease. The growth of fungal colonies was not observed on R. alboglabra leaves at 1, 2, 4, 6, 8, and 10 days post-inoculation (dpi), whereas this was clearly observed on B. napus leaves after 6 dpi. In addition, the gene expression of six plant defense-related genes, namely, PR-1, PR-2 (a marker for SA signaling), PR-3, PDF 1.2 (a marker for JA/ET signaling), CHI620, and CHI570, for both genotypes were analyzed in the leaves of B. napus and R. alboglabra after treatment with TH12 or CF and compared with the non-treated ones. The qRT-PCR results showed that the PR-1 and PR-2 expression levels increased in E. cruciferarum-infected leaves, but decreased in the TH12-treated leaves compared with leaves treated with CF. The expression levels of PR-3 and PDF1.2 decreased in plants infected by E. cruciferarum. However, expression levels increased when the leaves were treated with TH12. For the first time, we disclosed the nature of gene expression in B. napus and R. alboglabra to explore the resistance pathways in the leaves of both genotypes infected and non-infected by powdery mildew and inoculated or non-inoculated with elicitor factors. Results suggested that R. alboglabra exhibited resistance to powdery mildew disease, and the application of T. harzianum and its CF are a useful tool to facilitate new protection methods for resist or susceptible plants.

Big Data: Big Confusion? Big Challenges?

DTIC Science & Technology

2015-05-01

ENERGY. ·•1•·•1•· ~ CISCO ~ ~ ~~ Carolinas HcalthCarc System ........•••••••............•••••••••••••••••••••.......................•. 12th Annual...making operational efficiency • Generating new data sources • Predictive analytics • Market research (AMA Survey top 5) 12th Annual

Laser based synthesis of nanofunctionalized particulates for pulmonary based controlled drug delivery applications

NASA Astrophysics Data System (ADS)

Singh, R. K.; Kim, W.-S.; Ollinger, M.; Craciun, V.; Coowantwong, I.; Hochhaus, G.; Koshizaki, N.

2002-09-01

There is an urgent need to develop controlled drug release systems for the delivery of drugs via the pulmonary route. A key issue in pulmonary dry delivery systems is to reduce the amount of biodegradable polymers that are added to control the drug release. We have synthesized nanofunctionalized drug particles using the pulsed laser deposition on particles (PLDP) (e.g. budesonide) in an effort to control the architecture and thickness of a nanoscale polymer coating on the drug particles. In vitro studies indicated that the dry half-life release for budesonide can be enhanced from 1.2 to over 60 min by a nanoscale coating on the drug particle. Extensive studies have been conducted to characterize the bonding and composition of the polymer film deposited on drug particles.

Fabrication of CA/TPU Helical Nanofibers and its Mechanism Analysis

NASA Astrophysics Data System (ADS)

Wu, Huihui; Zhao, Shihang; Han, Lei

2018-04-01

To explore the mechanism of cellulose acetate (CA)/thermoplastic polyurethane (TPU) on the fabrication of helical nanofibers, a series of experiments were conducted to find the optimum spinning conditions. The experimental results show that the CA (14 wt%, DMAc/acetone, 1/2 volume ratio)/TPU2 (18 wt%, DMAc/acetone, 3/1 volume ratio) system can fabricate helical nanofibers effectively via co-electrospinning. We focus on the interfacial interaction between the polymer components induced by the polymer structure and intrinsic properties, including solution properties, hydrogen bonding, and miscibility behavior of the two solutions. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) are employed to investigate the interfacial interaction between the two phases of the polymer system. The analysis results provide the explanation of the experimental results that the CA/TPU system has the potential for producing helical nanofibers effectively. This study based on the interfacial interaction between polymer components provides an insight into the mechanism of CA/TPU helical fiber formation and introduces a richer choice of materials for the application of helical fibers.

Nanoimprinting-induced nanomorphological transition in polymer solar cells: enhanced electrical and optical performance.

PubMed

Jeong, Seonju; Cho, Changsoon; Kang, Hyunbum; Kim, Ki-Hyun; Yuk, Youngji; Park, Jeong Young; Kim, Bumjoon J; Lee, Jung-Yong

2015-03-24

We have investigated the effects of a directly nanopatterned active layer on the electrical and optical properties of inverted polymer solar cells (i-PSCs). The capillary force in confined molds plays a critical role in polymer crystallization and phase separation of the film. The nanoimprinting process induced improved crystallization and multidimensional chain alignment of polymers for more effective charge transfer and a fine phase-separation between polymers and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) to favor exciton dissociation and increase the generation rate of charge transfer excitons. Consequently, the power conversion efficiency with a periodic nanostructure was enhanced from 7.40% to 8.50% and 7.17% to 9.15% in PTB7 and PTB7-Th based i-PSCs, respectively.

Energy Systems - Present, Future: Extra Terrestrials, Grades 7, 8, 9,/Science.

ERIC Educational Resources Information Center

National Science Teachers Association, Washington, DC.

The 12 lessons presented in this guide are structured so that they may be integrated into science lessons in 7th-, 8th-, or 9th-grades. Suggestions are made for extension of study. Lessons are approached through classroom role-playing of outer space visitors who seek to understand energy conversion principles used on Earth. Major emphasis is…

Comparison of toxicity rankings of six aircraft cabin polymers by lethality and by incapacitation in rats.

PubMed

Sanders, D C; Endecott, B R; Chaturvedi, A K

1992-10-01

Polymeric aircraft cabin materials have the potential to produce toxic gases in fires. Lethality (LC50) in animal models is a standard index to rank polymers on the basis of their combustion toxicity. However, the use of times-to-incapacitation (ti) may be more realistic for predicting relative escape times from a fire. Therefore, LC50 and ti for polymers, polyamide (I), polystyrene (II), Nylon 6/6 (III), polysulfone (IV), polyethylene (V) and chlorinated polyethylene (VI), of different chemical classes were determined and compared. Male rats, 12/fuel loading, were exposed to the pyrolysis products from selected weights of each polymer for 30 min in a 265-L combustion/exposure system, and LC50 values were determined following a 14-d observation period. For each polymer, ti was measured at 16 g and at its respective LC50 using the inability of rats (n greater than or equal to 12) to walk in rotating cages as a criterion for incapacitation. LC50 (45.7-87.5 mg/L) of the polymers had the order of I less than II approximately III less than IV less than V less than VI, while their ti (6.6-21.1 min) at 16 g (60 mg/L) had the order of III approximately I less than V approximately II less than VI less than IV. Based on ti at LC50, polymers were grouped into III & V; I, II & VI; and IV. LC50 and ti did not exhibit the same relative toxic hazard rankings for these polymers; ti were also not equal at the LC50 concentrations. These findings demonstrate the possible involvement of different mechanisms of action for the combustion products of these polymers at the selected end points.

Electrospinning Applications in Mechanochemistry and Multi-Functional Hydrogel Materials

DTIC Science & Technology

2012-01-01

Price, G. J., Annu. Rev. Mater. Sci. 1999, 29, 295-326. 11. Koda , S.; Mori, H.; Matsumoto, K.; Nomura, H., Polymer 1994, 35 (1), 30-33. 
13
 12...Polymer Science: Polymer Letters Edition 1980, 18 (12), 757-760. 14. Koda , S.; Mori, H.; Matsumoto, K.; Nomura, H., Polymer 1994, 35 (1), 30-33

40 CFR 721.10400 - Oxirane, 2-ethyl-, polymer with oxirane, mono-C12-14-sec-alkyl ethers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Oxirane, 2-ethyl-, polymer with... Significant New Uses for Specific Chemical Substances § 721.10400 Oxirane, 2-ethyl-, polymer with oxirane...) The chemical substance identified as oxirane, 2-ethyl-, polymer with oxirane, mono-C12-14-sec-alkyl...

How do we extract the three chi's that describe a compressible blend from SANS ?

NASA Astrophysics Data System (ADS)

Gujrati, P. D.; Rane, Sagar

2000-03-01

We demonstrate that a lattice model of a compressible blend is characterized by three bare chi parameters; chi-01 (between void and polymer1), chi-02 (between void and polymer2) and chi-12 (between polymer1 and polymer2). We propose a methodology to extract the corresponding three effective chi's from the scattering intensity and additional information on the compressibility and partial molar volumes. We have also defined and obtained a single effective chi for the blend (without RPA) and compared this single effective chi with the other three effective chi's. In all calculations, the athermal part was removed exactly resulting in an interaction part which remains finite over the entire composition regime. From thermodynamics, we know that this single chi is not the same as chi-12, and we shall determine when the two are close or similar. We have also obtained the values of the three chi's at the critical point for different systems to display their utility. We have carried out the calculations in different ensembles and find that the value of chi's depend on the ensemble chosen.

The effects of space radiation on a chemically modified graphite-epoxy composite material

NASA Technical Reports Server (NTRS)

Reed, S. M.; Herakovich, C. T.; Sykes, G. F.

1986-01-01

The effects of the space environment on the engineering properties and chemistry of a chemically modified T300/934 graphite-epoxy composite system are characterized. The material was subjected to 1.0 x 10 to the 10th power rads of 1.0 MeV electron irradiation under vacuum to simulate 30 years in geosynchronous earth orbit. Monotonic tension tests were performed at room temperature (75 F/24 C) and elevated temperature (250 F/121 C) on 4-ply unidirectional laminates. From these tests, inplane engineering and strength properties (E sub 1, E sub 2, Nu sub 12, G sub 12, X sub T, Y sub T) were determined. Cyclic tests were also performed to characterize energy dissipation changes due to irradiation and elevated temperature. Large diameter graphite fibers were tested to determine the effects of radiation on their stiffness and strength. No significant changes were observed. Dynamic-mechanical analysis demonstrated that the glass transition temperature was reduced by 50 F(28 C) after irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated material. The chemical modification of the epoxy did not aid in producing a material which was more radiation resistant than the standard T300/934 graphite-epoxy system. Irradiation was found to cause crosslinking and chain scission in the polymer. The latter produced low molecular weight products which plasticize the material at elevated temperatures and cause apparent material stiffening at low stresses at room temperature.

25th Anniversary Article: Ordered Polymer Structures for the Engineering of Photons and Phonons

PubMed Central

Lee, Jae-Hwang; Koh, Cheong Yang; Singer, Jonathan P; Jeon, Seog-Jin; Maldovan, Martin; Stein, Ori; Thomas, Edwin L

2014-01-01

The engineering of optical and acoustic material functionalities via construction of ordered local and global architectures on various length scales commensurate with and well below the characteristic length scales of photons and phonons in the material is an indispensable and powerful means to develop novel materials. In the current mature status of photonics, polymers hold a pivotal role in various application areas such as light-emission, sensing, energy, and displays, with exclusive advantages despite their relatively low dielectric constants. Moreover, in the nascent field of phononics, polymers are expected to be a superior material platform due to the ability for readily fabricated complex polymer structures possessing a wide range of mechanical behaviors, complete phononic bandgaps, and resonant architectures. In this review, polymer-centric photonic and phononic crystals and metamaterials are highlighted, and basic concepts, fabrication techniques, selected functional polymers, applications, and emerging ideas are introduced. PMID:24338738

Passive and electro-optic polymer photonics and InP electronics integration

NASA Astrophysics Data System (ADS)

Zhang, Z.; Katopodis, V.; Groumas, P.; Konczykowska, A.; Dupuy, J.-.; Beretta, A.; Dede, A.; Miller, E.; Choi, J. H.; Harati, P.; Jorge, F.; Nodjiadjim, V.; Dinu, R.; Cangini, G.; Vannucci, A.; Felipe, D.; Maese-Novo, A.; Keil, N.; Bach, H.-.; Schell, Martin; Avramopoulos, H.; Kouloumentas, Ch.

2015-05-01

Hybrid photonic integration allows individual components to be developed at their best-suited material platforms without sacrificing the overall performance. In the past few years a polymer-enabled hybrid integration platform has been established, comprising 1) EO polymers for constructing low-complexity and low-cost Mach-Zehnder modulators (MZMs) with extremely high modulation bandwidth; 2) InP components for light sources, detectors, and high-speed electronics including MUX drivers and DEMUX circuits; 3) Ceramic (AIN) RF board that links the electronic signals within the package. On this platform, advanced optoelectronic modules have been demonstrated, including serial 100 Gb/s [1] and 2x100 Gb/s [2] optical transmitters, but also 400 Gb/s optoelectronic interfaces for intra-data center networks [3]. To expand the device functionalities to an unprecedented level and at the same time improve the integration compatibility with diversified active / passive photonic components, we have added a passive polymer-based photonic board (polyboard) as the 4th material system. This passive polyboard allows for low-cost fabrication of single-mode waveguide networks, enables fast and convenient integration of various thin-film elements (TFEs) to control the light polarization, and provides efficient thermo-optic elements (TOEs) for wavelength tuning, light amplitude regulation and light-path switching.

Mirror symmetry breaking of silicon polymers--from weak bosons to artificial helix.

PubMed

Fujiki, Michiya

2009-01-01

From elemental particles to human beings, matter and living worlds in our universe are dissymmetric with respect to mirror symmetry. Since the early 19th century, the origin of biomolecular handedness has been puzzling scientists. Nature's elegant bottom-up preference, however, sheds light on new concepts of generating, amplifying, and switching artificial polymers, supramolecules, liquid crystals, and organic crystals that can exhibit ambidextrous circular dichroism in the UV/Visible region with efficiency in production under milder ambient conditions. In the 1920s, Kipping, who first synthesized polysilanes with phenyl groups, had much interest in the handedness of inorganic and organic substances from 1898 to 1909 in his early research life. Polysilanes--which are soluble Si-Si bonded chain-like near-UV chromophores that carry a rich variety of organic groups--may become a bridge between animate and inanimate polymer systems. The present account focuses on several mirror symmetry breaking phenomena exemplified in polysilanes carrying chiral and/or achiral side groups, which are in isotropic dilute solution, as polymer particles dispersed in solution, and in a double layer film immobilized at the solid surface, and subtle differences in the helix, by dictating ultimately ultraweak chiral forces at subatomic, atomic, and molecular levels. Copyright 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Formative Assessment for College Readiness: Measuring Skill and Growth in Five Key Cognitive Strategies Associated with Postsecondary Success

ERIC Educational Resources Information Center

Conley, David; Lombardi, Allison; Seburn, Mary; McGaughy, Charis

2009-01-01

This study reports the preliminary results from a field test of the College-readiness Performance Assessment System (C-PAS), a large-scale, 6th-12th grade criterion-referenced assessment system that utilizes classroom-embedded performance tasks to measure student progress toward the development of key cognitive skills associated with success in…

A clinical evaluation of the ProNOVA XR polymer-free sirolimus eluting coronary stent system in the treatment of patients with de novo coronary artery lesions (EURONOVA XR I study)☆

PubMed Central

Legutko, Jacek; Zasada, Wojciech; Kałuża, Grzegorz L.; Heba, Grzegorz; Rzeszutko, Lukasz; Jakala, Jacek; Dragan, Jacek; Klecha, Artur; Giszterowicz, Dawid; Dobrowolski, Wojciech; Partyka, Łukasz; Jayaraman, Swaminathan; Dudek, Dariusz

2013-01-01

Aims Evaluation of safety and efficacy of ProNOVA XR, a new generation of polymer-free sirolimus eluting stents (SES), utilizing a pharmaceutical excipient for timed release of sirolimus from the XR platform. Methods and results Safety and efficacy of ProNOVA XR coronary stent system was examined in EURONOVA prospective, single arm, multi-center registry of 50 patients with de novo native coronary lesions up to 28 mm in length in arteries between 2.25 and 4 mm. At 6-month, in-stent late lumen loss by QCA was 0.45 ± 0.41 mm and in-stent neointimal volume obstruction in the IVUS sub-study was 14 ± 11%. One-year clinical follow-up revealed a favorable safety profile, with 2% of in-hospital MACE and 6.4% of MACE from hospital discharge up to 12 months (including 1 cardiac death >30 days after stent implantation and 2 TLRs). According to the ARC definition, there was no definite or probable stent thrombosis and 1 possible stent thrombosis (2%) up to 12 months of clinical follow-up. Conclusions In this preliminary evaluation, ProNOVA XR polymer-free sirolimus eluting stent system appeared safe with an early promise of adequate effectiveness in the treatment of de novo coronary lesions in up to 12 months of clinical, angiographic and IVUS follow-up. PMID:23992999

12 CFR 269b.111 - Filing of charges.

Code of Federal Regulations, 2014 CFR

2014-01-01

... to the Secretary of the Federal Reserve System Labor Relations Panel, 20th Street and Constitution... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Filing of charges. 269b.111 Section 269b.111 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM...

12 CFR 269b.111 - Filing of charges.

Code of Federal Regulations, 2012 CFR

2012-01-01

... to the Secretary of the Federal Reserve System Labor Relations Panel, 20th Street and Constitution... 12 Banks and Banking 4 2012-01-01 2012-01-01 false Filing of charges. 269b.111 Section 269b.111 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM...

12 CFR 269b.111 - Filing of charges.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of the Federal Reserve System Labor Relations Panel, 20th Street and Constitution Avenue NW... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Filing of charges. 269b.111 Section 269b.111 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM...

Detecting the Hormonal Pathways in Oilseed Rape behind Induced Systemic Resistance by Trichoderma harzianum TH12 to Sclerotinia sclerotiorum.

PubMed

Alkooranee, Jawadayn Talib; Aledan, Tamarah Raad; Ali, Ali Kadhim; Lu, Guangyuan; Zhang, Xuekun; Wu, Jiangsheng; Fu, Chunhua; Li, Maoteng

2017-01-01

Plants have the ability to resist pathogen attack after infection or treatment with biotic and abiotic elicitors. In oilseed rape plant Brassica napus AACC and in the artificially synthesized Raphanus alboglabra RRCC, the root-colonizing Trichoderma harzianum TH12 fungus triggers induced systemic resistance (ISR), and its culture filtrate (CF) triggers a systemic acquired resistance (SAR) response against infection by the Sclerotinia sclerotiorum. Salicylic acid (SA) and jasmonic acid/ethylene (JA/ET) are plant hormone signals that play important roles in the regulation of ISR and SAR. In this study, at six different time points (1, 2, 4, 6, 8 and 10 days post-infection [dpi]), six resistance genes were used as markers of signaling pathways: JA/ET signaling used AOC3, PDF1.2 and ERF2 genes, while PR-1, TGA5 and TGA6 genes were used as markers of SA signaling. The results of quantitative real-time polymerase chain reaction (qRT-PCR) showed that AOC3, PDF1.2 and ERF2 expression levels in infected leaves of AACC and RRCC increase at 1 and 2 dpi with S. sclerotiorum or inoculation with TH12. PR-1, TGA5 and TGA6 expression levels increased at 8 and 10 dpi in infected leaves. PR-1, TGA5 and TGA6 expression levels increased early in plants treated with CF in both of the healthy genotypes. Furthermore, induction of SA- and JA/ET-dependent defense decreased disease symptoms in infected leaves at different times. The results suggest that the RRCC genotype exhibits resistance to disease and that the ability of TH12 and its CF to induce systemic resistance in susceptible and resistant oilseed rape genotypes exists. In addition, the results indicate for the first time that in RRCC the SA signaling pathway is involved in resistance to necrotrophic pathogens.

Optical mass memory system (AMM-13). AMM-13 system segment specification

NASA Technical Reports Server (NTRS)

Bailey, G. A.

1980-01-01

The performance, design, development, and test requirements for an optical mass data storage and retrieval system prototype (AMM-13) are established. This system interfaces to other system segments of the NASA End-to-End Data System via the Data Base Management System segment and is designed to have a storage capacity of 10 to the 13th power bits (10 to the 12th power bits on line). The major functions of the system include control, input and output, recording of ingested data, fiche processing/replication and storage and retrieval.

Situational analysis and future directions of AYUSH: An assessment through 5-year plans of India.

PubMed

Samal, Janmejaya

2015-01-01

AYUSH is an acronym for Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homeopathy. These are the six indigenous systems of medicine practiced in India. A department called Department of Indian System of medicine was created in March 1995 and renamed to AYUSH in November 2003 with a focus to provide increased attention for the development of these systems. Very recently, in 2014, a separate ministry was created under the union Government of India, which is headed by a minister of state. Planning regarding these systems of medicine was a part of 5-year planning process since 1951. Since then many developments have happened in this sector albeit the system was struggling with a great degree of uncertainty at the time of 1(st)5-year plan. A progressive path of development could be observed since the first to the 12(th)5-year plan. It was up to the 7(th)plan the growth was little sluggish and from 8(th)plan onward the growth took its pace and several innovative development processes could be observed thereafter. The system is gradually progressing ahead with a vision to be a globally accepted system, as envisaged in 11(th)5-year plan. Currently, AYUSH system is a part of mainstream health system implemented under National Rural Health Mission (NRHM). NRHM came into play in 2005 but implemented at ground level in 2006 and introduced the scheme of "Mainstreaming of AYUSH and revitalization of local health traditions" to strengthen public health services. This scheme is currently in operation in its second phase, since 1(st)April 2012, with the 12(th)5-year plan. The scheme was primarily brought in to operation with three important objectives; choice of treatment system to the patients, strengthen facility functionally and strengthen the implementation of national health programmes, however, in some places it seems to be a forced medical pluralism owing to a top-down approach by the union government without considerable involvement of the concerned community. In this study, the 5-year planning documents have been reviewed, from the 1(st)plan to 12(th)plan, to enable reflection and throw some light into the future directions of AYUSH system.

Conference on Stochastic Processes and Their Applications (12th) held at Ithaca, New York on 11-15 Jul 83,

DTIC Science & Technology

1983-07-15

RD- R136 626 CONFERENCE ON STOCHASTIC PROCESSES AND THEIR APPLICATIONS (12TH> JULY 11 15 1983 ITHACA NEW YORK(U) CORNELL UNIV ITHACA NY 15 JUL 83...oscillator phase Instability" 2t53 - 3s15 p.m. M.N. GOPALAN, Indian Institute of Technoloy, Bombay "Cost benefit analysis of systems subject to inspection...p.m. W. KLIEDANN, Univ. Bremen, Fed. Rep. Germany "Controllability of stochastic systems 8sO0 - lOsO0 p.m. RECEPTION Johnson Art Museum ’q % , t

Overwhelming Force, Indecisive Victory: The German Invasion of Yugoslavia, 1941

DTIC Science & Technology

1993-05-13

It was a system of large units that depended primarily on animal draft power for transportation that resulted in low march speed and lack of...STUBOL* 12 3D BOMBER REGT SKOPLJE* 13 63D BOMBER GROUP PZTROVAC 30 D017 13 64TH BOMBER GROUP PSTROVAC 30 DOl0 14 5TH FIGHTER RIGT NIS* 15 35TH...FIGHTER GROUP KOSANCIC 15 HAWKER FURY 16 36TH FIGHTER GROUP REZANOVACKA KOSA 15 HAWKER FURY 17 4TH BOMBER AIR BDE LJUBIC* 18 1ST BOMBER RIGT NOVI SAD* 19

Phase-Equilibria and Nanostructure Formation in Charged Rigid-Rod Polymers and Carbon Nanotubes

DTIC Science & Technology

2002-11-10

or liquid crystalline) and the crystalline polymer state. The form-I crystal solvate, identi- fied as a cocrystal of the protonated polymer and the...dissolution temperature, below 100 °C.12,13 The form-II crystal solvate, considered a polymer-solvent cocrystal in which the polymer is deprotonated,11,12...solvate that is a cocrystal of protonated PBZT and PPA anions. As previously mentioned, the fact that these two extreme cases result in similar

Integrated Analysis Tools for Determination of Structural Integrity and Durability of High temperature Polymer Matrix Composites

DTIC Science & Technology

2008-08-18

fidelity will be used to reduce the massive experimental testing and associated time required for qualification of new materials. Tools and...develping a model of the thermo-oxidative process for polymer systems, that incorporates the effects of reaction rates, Fickian diffusion, time varying...degradation processes. Year: 2005 Month: 12 Not required at this time . AIR FORCE OFFICE OF SCIENTIFIC KESEARCH 04 SEP 2008 Page 2 of 2 DTIC Data

76 FR 50811 - Seventeenth Meeting: EUROCAE WG-72: RTCA Special Committee 216: Aeronautical Systems Security...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-16

.... Agenda Tuesday, September 6th (Pre-Meeting Events) 9 a.m. to 12 p.m. Optional--DHS National Cybersecurity... cooperation. 11:15 a.m.-12 p.m., DHS Briefing on the Cybersecurity Control System Security (CSSP) Program. 1 p...

Astronomy Education through the NSF GK-12 Program

NASA Astrophysics Data System (ADS)

Jensen, A. G.

2004-05-01

The National Science Foundation's GK-12 program encourages graduate students in science to be active in public education at the middle school and high school levels. As a GK-12 fellow at the University of Colorado-Boulder (CU), I worked with a local 8th-grade science teacher and his students during the 2003-2004 school year. In the Boulder Valley School District, 8th-grade science covers Earth history, meteorology, astronomy, and oceanography. There are many special challenges for this school district and 8th-grade education in Colorado, including a large number of English as a second language (ESL) students and the administration of standardized tests during March, before students have completed much of the relevant material. As a GK-12 Fellow, my responsibilities included work with the Earth history Full Option Science System (FOSS) kit, guest lecturing, aid in hands-on exercises, and the creation of new activities and assignments. Astronomy activities accomplished through this program include sunspot viewing and a field trip to the Colorado Scale Model Solar System on the CU campus. The GK-12 program at CU will continue for at least two more years, possibly placing future GK-12 fellows who are astronomy grad students into classes that are astronomy- or physics-specific.

Effect of body mass index on functional outcomes following arthroplasty procedures.

PubMed

Polat, Gokhan; Ceylan, Hasan Huseyin; Sayar, Safak; Kucukdurmaz, Fatih; Erdil, Mehmet; Tuncay, Ibrahim

2015-12-18

To evaluate the body mass index (BMI) change in arthroplasty patients and its impact on the patients' functional results. Between October 2010 and May 2013, 606 patients who were operated due to gonarthrosis, coxarthrosis, aseptic loosening of the total knee and hip prosthesis were evaluated prospectively. Patients were operated by three surgeons in three medical centers. Patients who were between 30-90 years of age and who were underwent total knee arthroplasty, total hip arthroplasty, revision knee arthroplasty, or revision hip arthroplasty were included in the study. We excluded the patients who cannot tolerate our standard postoperative rehabilitation program. Additionally, patients who had systemic inflammatory diseases, diabetes mellitus, or endochrinopathies were excluded from the study. The remaining 513 patients comprised our study group. Preoperative functional joint scores, height, weight and BMI of all patients were recorded. We used the Knee Society Score (KSS) for knee and Harris Hip Score (HHS) for hip patients. Postoperative functional scores were measured at 1(st), 6(th) and 12(th) months and recorded separately at outpatient visits. The mean age of the patients was 64.7 (range: 30-90) years (207 males/306 females) and the mean follow-up duration was 14.3 (range: 12-26) mo. We found that arthroplasty patients had weight gain and had an increase in BMI at the postoperative 1(st), 6(th) and 12(th) months. The mean BMI of the patients was 27.7 preoperatively, 27.8 at the postoperative 1(st) month, 28.1 at the 6(th) month and 28.6 at the 12(th) month (P < 0.01). At the last visit, the mean postoperative HHS of the hip arthroplasty patients was 82.2 ± 7.12 (preoperatively, 52.3; 1(st) month, 78.2; 6(th) month, 81.1; 12(th) month, 82.2), and the mean KSS of the knee arthroplasty patients was 79.3 ± 4.31 (preoperatively, 35.8; 1(st) month, 75.2; 6(th) month, 79.1; 12(th) month, 79.3). Worse functional results were noted in the patients who had a BMI increase, however, this correlation was statistically significant only at the postoperative 6(th) month (P = 0.03). To prevent the negative functional effects of this weight gain during the postoperative period, arthroplasty patients should be advised for weight control and risky patients should consult with a dietician.

Direct Measurements of Long-Range Repulsive Interactions in the L_α phase of Polymer-Coated Highly Flexible Membranes

NASA Astrophysics Data System (ADS)

Warriner, Heidi E.; Safinya, Cyrus R.

1997-03-01

Using two complimentary techniques, we have measured repulsive interactions in the L_α phase of very flexible membranes composed of the surfactant C12E5 and small amounts of polymer-lipids derived from polyethylene glycol (PEG-DMPE 5000, PEG-DMPE 2000 and PEG-DMPE 550). In the first method, the lamellar repeat distance of samples in equilibrium with a dextran solution of known osmotic pressure is determined, yielding a direct measurement of pressure versus distance. These data immediately differentiate the repulsive interaction between flexible polymer-decorated membranes from polymer-brush forces found in rigid lamellar systems. In the second method, fits to high-resolution x-ray data yield the η parameter, proportional to (κB)-1\\over2, where B is the layer compressional modulus and κ is the bending rigidity of a single membrane. Combining the two types of data to eliminate B, one can quantitatively determine the κ of a decorated membrane as a function of polymer-lipid concentration. For the bare C12E5 membrane, where κ is known , a direct comparison of the compressibility modulus values derived via the two methods is also possible. This work supported by NSF-DMR-9624091; PRF-31352-AC7 CULAR-STB/UC:96-118.

Catalytic molecularly imprinted polymer membranes: development of the biomimetic sensor for phenols detection.

PubMed

Sergeyeva, T A; Slinchenko, O A; Gorbach, L A; Matyushov, V F; Brovko, O O; Piletsky, S A; Sergeeva, L M; Elska, G V

2010-02-05

Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)-catechol-urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes' structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers-biomimics with the optimized composition comprised 0.063 mM, while the linear range of the sensor comprised 0.063-1 mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols detection the developed sensor system is characterized by simplicity of operation, compactness, and low cost. Copyright 2009 Elsevier B.V. All rights reserved.

Electrical study on Carboxymethyl Cellulose-Polyvinyl alcohol based bio-polymer blend electrolytes

NASA Astrophysics Data System (ADS)

Saadiah, M. A.; Samsudin, A. S.

2018-04-01

The present work deals with the formulation of bio-materials namely carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) for bio-polymer blend electrolytes (BBEs) system which was successfully carried out with different ratio of polymer blend. The biopolymer blend was prepared via economical & classical technique that is solution casting technique and was characterized by using impedance spectroscopy (EIS). The ionic conductivity was achieved to optimum value 9.12 x 10-6 S/cm at room temperature for sample containing ratio 80:20 of CMC:PVA. The highest conducting sample was found to obey the Arrhenius behaviour with a function of temperature. The electrical properties were analyzed using complex permittivity ε* and complex electrical modulus M* for BBEs system and it shows the non-Debye characteristics where no single relaxation time has observed.

Nonlinear optical properties of organic materials V; Proceedings of the 5th Meeting, San Diego, CA, July 22-24, 1992

NASA Astrophysics Data System (ADS)

Williams, David J.

The present volume on nonlinear optical properties of organic materials discusses organic nonlinear optics, polymers for nonlinear optics, characterization of nonlinear properties, photorefractive and second-order materials, harmonic generation in organic materials, and devices and applications. Particular attention is given to organic semiconductor-doped polymer glasses as novel nonlinear media, heterocyclic nonlinear optical materials, loss measurements in electrooptic polymer waveguides, the phase-matched second-harmonic generation in planar waveguides, electrooptic measurements in poled polymers, transient effects in spatial light modulation by nonlinearity-absorbing molecules, the electrooptic effects in organic single crystals, surface acoustic wave propagation in an organic nonlinear optical crystal, nonlinear optics of astaxanthin thin films; and advanced high-temperature polymers for integrated optical waveguides. (No individual items are abstracted in this volume)

Propeller-shaped acceptors for high-performance non-fullerene solar cells: Importance of the rigidity of molecular geometry

DOE PAGES

Wu, Qinghe; Zhao, Donglin; Yang, Jinghui; ...

2017-01-06

This study describes the synthesis and application of βTPB6 and βTPB6-C as electron acceptors for organic solar cells. Compound βTPB6 contains four covalently bonded PDIs with a BDT-Th core at the β-position. The free rotation of PDIs renders βTPB6 with varying molecular geometries. The cyclization of βTPB6 yields βTPB6-C with high rigidity of the molecular geometry and enlarged conjugated skeleton. The inverted solar cells based on βTPB6-C and PTB7-Th as the donor polymer exhibited the highest efficiency of 7.69% with V oc of 0.92 V, J sc of 14.9 mAcm –2, and FF of 0.56, which is 31% higher thanmore » that for βTPB6 based devices. The larger fraction of βTPB6-C and PTB7-Th than that of βTPB6:PTB7-Th in a blend film takes a face-on orientation packing pattern for π-systems that benefits the charge transport and hence higher PCE value than that for βTPB6:PTB7-Th. It was also found that a proper DIO:DPE additive further enhances this trend, which results in an increase of the PCE value for βTPB6-C:PTB7-Th while decreasing the PCE value for βTPB6:PTB7-Th.« less

Propeller-shaped acceptors for high-performance non-fullerene solar cells: Importance of the rigidity of molecular geometry

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

Wu, Qinghe; Zhao, Donglin; Yang, Jinghui

This study describes the synthesis and application of βTPB6 and βTPB6-C as electron acceptors for organic solar cells. Compound βTPB6 contains four covalently bonded PDIs with a BDT-Th core at the β-position. The free rotation of PDIs renders βTPB6 with varying molecular geometries. The cyclization of βTPB6 yields βTPB6-C with high rigidity of the molecular geometry and enlarged conjugated skeleton. The inverted solar cells based on βTPB6-C and PTB7-Th as the donor polymer exhibited the highest efficiency of 7.69% with V oc of 0.92 V, J sc of 14.9 mAcm –2, and FF of 0.56, which is 31% higher thanmore » that for βTPB6 based devices. The larger fraction of βTPB6-C and PTB7-Th than that of βTPB6:PTB7-Th in a blend film takes a face-on orientation packing pattern for π-systems that benefits the charge transport and hence higher PCE value than that for βTPB6:PTB7-Th. It was also found that a proper DIO:DPE additive further enhances this trend, which results in an increase of the PCE value for βTPB6-C:PTB7-Th while decreasing the PCE value for βTPB6:PTB7-Th.« less

How Do Teacher Evaluation Ratings on Kentucky's Professional Growth and Effectiveness System Relate to Student Achievement?

ERIC Educational Resources Information Center

Masters, Jim

2017-01-01

The purpose of this study was to determine if a teacher's Professional Growth and Effectiveness System (PGES) rating is an effective indicator for student achievement. Participants in the study were 9th through 12th grade English 10, Biology, U.S. History and Algebra 2 teachers and students enrolled in their courses. The teacher participants'…

40 CFR 721.10286 - Formaldehyde, polymer with .alpha.- (2-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly...

Code of Federal Regulations, 2013 CFR

2013-07-01

...-aminomethylethyl)- .omega. - (2 - aminomethylethoxy)poly[ oxy(methyl - 1,2 - ethanediyl)] and 4 - (1,1... Specific Chemical Substances § 721.10286 Formaldehyde, polymer with .alpha.- (2-aminomethylethyl)- .omega... formaldehyde, polymer with .alpha.-(2-aminomethylethyl)-.omega.-(2-aminomethylethoxy)poly[oxy(methyl-1,2...

Exploring the Thermal and Mechanochemical Reactivity of 1,2-Oxazine Hetero-Diels-Alder Adducts for Stimuli-Responsive Polymers

NASA Astrophysics Data System (ADS)

Church, Derek C.

Stimuli-responsive materials is an area of significant research with a broad scope of applications in fields such as drug delivery, self-healing materials, and lithography. The ideal stimuli-responsive polymer construct is engineered in such a way that the desired activation occurs only when the proper stimuli is spatially and temporally applied. Light-, pH-, redox-, thermal-, mechanical- and enzymatic-stimuli have successfully been harnessed to trigger various responses in polymeric materials. The continued growth of this field relies upon the development of new stimuli-responsive chemical motifs. To this end, my research has focused on the potential of 1,2-oxazines as a new stimuli-responsive moiety within the context of polymer systems. These compounds have been demonstrated to undergo a thermally induced [4 + 2] cycloreversion to release a diene and nitrosocarbonyl dienophile. My research has sought to study and harness the thermal reversibility of this adduct and the subsequent breakdown of the dienophile component to trigger processes such as depolymerization of a polymer chain as well as releasing the therapeutically relevant gaseous small molecule, nitroxyl (HNO). Collectively, these constructs can achieve slow, sustained activation at physiologically relevant temperatures or rapid activation at higher temperatures by exogenous means such as the use of photothermal dyes. I have also looked at the propensity of 1,2-oxazines to undergo mechanochemical activation in solution under strong elongational fields. A fundamental understanding of not only how polymer topology may affect mechanophore activation in general but also the regiochemical application of force across the oxazine itself was explored.

77 FR 74473 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-14

... polymer. building materials. P-13-0022 10/12/2012 1/9/2013 CBI (S) Surface (G) protection agent Perfluoroacrylate for use in polymer. building materials. P-13-0023 10/12/2012 1/9/2013 CBI (G) Coating (G) Siloxanes and additive. silicones, substituted alkyl group-terminated, alkoxylated, polymers with...

40 CFR 721.10286 - Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega.-(2- aminomethylethoxy)poly[ oxy...

Code of Federal Regulations, 2014 CFR

2014-07-01

...-aminomethylethyl)- .omega.-(2- aminomethylethoxy)poly[ oxy(methyl- 1,2-ethanediyl)] and 4-(1,1-dimethylethyl)phenol... Specific Chemical Substances § 721.10286 Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega... formaldehyde, polymer with .alpha.-(2- aminomethylethyl)-.omega.-(2- aminomethylethoxy)poly[oxy(methyl- 1,2...

40 CFR 721.10286 - Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega.-(2-aminomethylethoxy) poly[oxy...

Code of Federal Regulations, 2012 CFR

2012-07-01

...-aminomethylethyl)- .omega.-(2-aminomethylethoxy) poly[oxy(methyl-1,2-ethanediyl)] and 4-(1,1-dimethylethyl)phenol... Specific Chemical Substances § 721.10286 Formaldehyde, polymer with .alpha.-(2-aminomethylethyl)- .omega... formaldehyde, polymer with .alpha.-(2-aminomethylethyl)-.omega.-(2-aminomethylethoxy)poly[oxy(methyl-1,2...

Experimental test of the variability of G using Viking lander ranging data

NASA Technical Reports Server (NTRS)

Hellings, R. W.; Adams, P. J.; Anderson, J. D.; Keesey, M. S.; Lau, E. L.; Standish, E. M.; Canuto, V. M.; Goldman, I.

1983-01-01

Results are presented from the analysis of solar-system astrometric data, notably the range data to the Viking landers on Mars. A least-squares fit of the parameters of the solar system model to these data limits a simple time variation in the effective Newtonian gravitational constant to (2 + or - 4) x 10 to the -12th/yr and a rate of drift of atomic clocks relative to the implicit clock of relativistic dynamics to (1 + or - 8) x 10 to the -12th/yr. The error limits quoted are the result of uncertainties in the masses of the asteroids.

Theory of Passive Polymer Translocation Through Amphiphilic Membranes

NASA Astrophysics Data System (ADS)

Werner, Marco; Bathmann, Jasper; Baulin, Vladimir; Sommer, Jens-Uwe; ITN-SNAL''Smart Nano-ObjectsAlteration of Lipid-Bilayers''Team

We propose a theoretical framework for examining the translocation of flexible polymers through amphiphilic membranes: A generic model for monomer-membrane interactions is formulated and the Edwards equation is employed for calculating the free energy landscape of a polymer in a membrane environment. By the example of homopolymers it is demonstrated that polymer adsorption and the symmetry of conformations with respect to the membrane's mid-plane trigger passive polymer translocation in a narrow window of polymer hydrophobicity. We demonstrate that globular conformations can be taken into account by means of a screening of the external potential, which leads to excellent agreement of predicted translocation times with dynamic lattice Monte Carlo (MC) simulations. The work opens a theoretical road-map on how to design translocating flexible polymers by referring to universal phenomena only: adsorption and conformational symmetry. As confirmed by MC simulations on amphiphilic polymers, promising candidates of translocating polymers in practice are short-block amphiphilic copolymers, which in the limit of small block sizes resemble homopolymers on a coarse grained level. We gratefully thank the European Union's funding of the Initial Training Network SNAL (Grant agreement no. 608184) under the 7th Framework Programme.

Model Compound Studies of Rigid Rod Aromatic Heterocyclic Polymer Systems, the X-Ray Crystal Structure of 2,6-Diphenylbenzo (1,2-d; 5,4-d’) Diimidazole Tetrahydrate, C2OH14N4. 4H2O, a Model System for the Study of Polymer-Water Interaction in Polybenzimidazoles.

DTIC Science & Technology

1983-07-01

Marilyn Hunsaker and W. Wade Adams Polyimer Branch Nonmetallic Division Albert V. Fratini University of Dayton Research Institute 300 College Park...U. CONTRACT OR GRANT NUMUER(e) M. Hunsaker, and W. W. Adams , Air Force Wright I atudrcnrc Aeronautical Laboratories, Materials Laboratory F33615-81-C...Scientist. Co-authors were Marilyn Hunsaker and W. W. Adams , Materials Laboratory (AFWAL/MLHP); and Dr. Albert V. Fratini, University of Dayton Research

Polymer powders for selective laser sintering (SLS)

NASA Astrophysics Data System (ADS)

Schmid, Manfred; Amado, Antonio; Wegener, Konrad

2015-05-01

Selective Laser Sintering (SLS) is close to be accepted as a production technique (Additive Manufacturing). However, one problem limiting employment of SLS for additive manufacturing in a wide-ranging industrial scope is the narrow variety of applicable polymers. The commonly applied SLS powder to date is polyamide 12 (PA 12). PA 12 or ccompounds of PA 12 (dry blends) are approximately 90 % of complete industrial consumption. The remaining small quantity is distributed on polyamide 11 (PA11) and some other `exotic' polymers (TPU, PEBA, P(E)EK). Industry is awaiting commodity polymers like polypropylene (PP) or polyethylene (PE) crucial to open new market segments. But several approaches launching those polymers failed. But what are the reasons for the difficulties in developing new SLS powders? The contribution is to answer this and highlights the combination of intrinsic and extrinsic polymer properties necessary to generate a polymer powder promising for SLS application. Particle shape, powder distribution, thermal, rheological and optical requirements must be considered and only a particularly controlled property combination leads to successful SLS implementation. Thermal behavior, particle shape and -distribution is discussed in detail, although the other properties can't be disregarded for providing new commercially successful SLS powder finally.

Proposal of simple and novel method of capacity fading analysis using pseudo-reference electrode in lithium ion cells: Application to solvent-free lithium ion polymer batteries

NASA Astrophysics Data System (ADS)

Shono, Kumi; Kobayashi, Takeshi; Tabuchi, Masato; Ohno, Yasutaka; Miyashiro, Hajime; Kobayashi, Yo

2014-02-01

We propose a simple procedure for introducing a pseudo-reference electrode (PRE) to lithium ion batteries using isometric lithium metal placed between the cathode and anode, and we successfully obtained the cathode and anode voltage profiles, individual interfacial impedances, and the misalignment of the operation range between the cathode and anode after cycle operation. The proposed procedure is applicable to lithium ion battery systems using a solid electrolyte to prepare two cells with a lithium counter electrode. We determined the capacity decrease of a solvent-free lithium ion polymer battery consisting of a LiNi1/3Mn1/3Co1/3O2 (NMC), a polyether-based solid polymer electrolyte (SPE), and a graphite (Gr) with the proposed PRE over 1000 cycles. The capacity retention of the [Gr|SPE|NMC] cell reached 50% at the 1000th cycle upon the optimization of cell preparation, and we found that the main factor of the capacity decrease was the continuous irreversible loss of active lithium at the graphite anode, not the oxidation of the SPE. Our findings suggest that we should reconsider combining a polyether-based SPE with a conventionally used 4 V class cathode and a graphite anode to develop an innovative, safe, and low-cost battery for the expected large lithium ion battery systems for stationary use.

Senior High School Earth Sciences and Marine Sciences.

ERIC Educational Resources Information Center

Hackenberg, Mary; And Others

This guide was developed for earth sciences and marine sciences instruction in the senior high schools of Duval County, Jacksonville, Florida. The subjects covered are: (1) Earth Science for 10th, 11th, and 12th graders; (2) Marine Biology I for 10th, 11th, and 12th graders; (3) Marine Biology II, Advanced, for 11th and 12th graders; (4) Marine…

Development of dispersion strengthened nickel-chromium alloy (Ni-Cr-ThO2) sheet for space shuttle vehicles, part 2

NASA Technical Reports Server (NTRS)

Klingler, L. J.; Weinberger, W. R.; Bailey, P. G.; Baranow, S.

1972-01-01

Two dispersion strengthened nickel base alloy systems were developed for use at temperatures up to 1204 C(2200 F); TD nickel chromium (TDNiCr) and TD nickel chromium aluminum (TDNiCrA1). They are considered candidate materials for use on the thermal protection systems of the space shuttle and for long term use in aircraft gas turbine engine applications. Improved manufacturing processes were developed for the fabrication of TDNiCr sheet and foil to specifications. Sheet rolling process studies and extrusion studies were made on two aluminum containing alloys: Ni-16%Cr-3.5%A1-2%ThO2 and Ni-16%Cr-5.0%A12%ThO2. Over 1600 kg.(3500 lb.) of plate, sheet, foil, bar and extrusion products were supplied to NASA Centers for technology studies.

A Polymer/Oil Based Nanovaccine as a Single-Dose Immunization Approach

PubMed Central

Vicente, Sara; Diaz-Freitas, Belen; Peleteiro, Mercedes; Sanchez, Alejandro; Pascual, David W.; Gonzalez-Fernandez, Africa; Alonso, Maria J.

2013-01-01

The recognized necessity for new antigen delivery carriers with the capacity to boost, modulate and prolong neutralizing immune responses prompted our approach, in which we describe a multifunctional nanocarrier consisting of an oily nanocontainer protected by a polymeric shell made of chitosan (CS), named CS nanocapsules (CSNC). The CS shell can associate the antigen on its surface, whereas the oily core might provide additional immunostimulating properties. In this first characterization of the system, we intended to study the influence of different antigen organizations on the nanocarrier's surface (using the recombinant hepatitis B surface antigen –rHBsAg– as a model antigen) on their long-term immunopotentiating effect, without any additional immunostimulant. Thus, two prototypes of antigen-loaded CSNC (CSNC+ and CSNC−), exhibiting similar particle size (200 nm) and high antigen association efficiency (>80%), were developed with different surface composition (polymer/antigen ratios) and surface charge (positive/negative, respectively). The biological evaluation of these nanovaccines evidenced the superiority of the CSNC+ as compared to CSNC- and alum-rHBsAg in terms of neutralizing antibody responses, following intramuscular vaccination. Moreover, a single dose of CSNC+ led to similar IgG levels to the positive control. The IgG1/IgG2a ratio suggested a mixed Th1/Th2 response elicited by CSNC+, in contrast to the typical Th2-biased response of alum. Finally, CSNC+ could be freeze-dried without altering its physicochemical properties and adjuvant effect in vivo. In conclusion, the evaluation of CSNC+ confirms its interesting features for enhancing, prolonging and modulating the type of immune response against subunit antigens, such as rHBsAg. PMID:23614052

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2010 CFR

2010-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10185 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1...

The NEEDS Data Base Management and Archival Mass Memory System

NASA Technical Reports Server (NTRS)

Bailey, G. A.; Bryant, S. B.; Thomas, D. T.; Wagnon, F. W.

1980-01-01

A Data Base Management System and an Archival Mass Memory System are being developed that will have a 10 to the 12th bit on-line and a 10 to the 13th off-line storage capacity. The integrated system will accept packetized data from the data staging area at 50 Mbps, create a comprehensive directory, provide for file management, record the data, perform error detection and correction, accept user requests, retrieve the requested data files and provide the data to multiple users at a combined rate of 50 Mbps. Stored and replicated data files will have a bit error rate of less than 10 to the -9th even after ten years of storage. The integrated system will be demonstrated to prove the technology late in 1981.

Mathematical modeling of nitrous oxide production in an anaerobic/oxic/anoxic process.

PubMed

Ding, Xiaoqian; Zhao, Jianqiang; Hu, Bo; Chen, Ying; Ge, Guanghuan; Li, Xiaoling; Wang, Sha; Gao, Kun; Tian, Xiaolei

2016-12-01

This study incorporates three currently known nitrous oxide (N 2 O) production pathways: ammonium-oxidizing bacteria (AOB) denitrification, incomplete hydroxylamine (NH 2 OH) oxidation, and heterotrophic denitrification on intracellular polymers, into a mathematical model to describe N 2 O production in an anaerobic/oxic/anoxic (AOA) process for the first time. The developed model was calibrated and validated by four experimental cases, then evaluated by two independent anaerobic/aerobic (AO) studies from literature. The modeling results displayed good agreement with the measured data. N 2 O was primarily generated in the aerobic stage by AOB denitrification (67.84-81.64%) in the AOA system. Smaller amounts of N 2 O were produced via incomplete NH 2 OH oxidation (15.61-32.17%) and heterotrophic denitrification on intracellular polymers (0-12.47%). The high nitrite inhibition on N 2 O reductase led to the increased N 2 O accumulation in heterotrophic denitrification on intracellular polymers. The new model was capable of modeling nitrification-denitrification dynamics and heterotrophic denitrification on intracellular polymers in the AOA system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gamma scintigraphic evaluation of floating gastroretentive tablets of metformin HCl using a combination of three natural polymers in rabbits

PubMed Central

Razavi, Mahboubeh; Karimian, Hamed; Yeong, Chai Hong; Chung, Lip Yong; Nyamathulla, Shaik; Noordin, Mohamed Ibrahim

2015-01-01

The present research was aimed at formulating a metformin HCl sustained-release formulation from a combination of polymers, using the wet granulation technique. A total of 16 formulations (F1–F16) were produced using different combinations of the gel-forming polymers: tamarind kernel powder, salep (palmate tubers of Orchis morio), and xanthan. Post-compression studies showed that there were no interactions between the active drug and the polymers. Results of in vitro drug-release studies indicated that the F10 formulation which contained 5 mg of tamarind kernel powder, 33.33 mg of xanthan, and 61.67 mg of salep could sustain a 95% release in 12 hours. The results also showed that F2 had a 55% similarity factor with the commercial formulation (C-ER), and the release kinetics were explained with zero order and Higuchi models. The in vivo study was performed in New Zealand White rabbits by gamma scintigraphy; the F10 formulation was radiolabeled using samarium (III) oxide (153Sm2O3) to trace transit of the tablets in the gastrointestinal tract. The in vivo data supported the retention of F10 formulation in the gastric region for 12 hours. In conclusion, the use of a combination of polymers in this study helped to develop an optimal gastroretentive drug-delivery system with improved bioavailability, swelling, and floating characteristics. PMID:26273196

RADIATION MALFORMATIONS BELONGING TO THE CYCLOPIA-ARRHINECEPHALIA- OCTOCEPHALIA GROUP IN THE MOUSE FETUS

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

Murakami, U.; Kameyama, Y.; Majima, A.

1962-03-01

Pregnant mice on the 8 1/2th day of gestation were subjected to 200 r whole-body irradiation and the fetuses were examined on the l3th to l9th day of gestation. Incidence of fetal death (23.0%) was much higher than in the controls (8.2%), and malformations of the nose, eyes, and ears occurred in 32%. These malformations included alterations leading to a beaklike snout (19%), a univentricular telencephalon with cyclopia (6%), and fomas transitional between these two (6%). These malformations were specific for irradiation on the 8 1/2th day of gestation. In previous studies they were not prominent when irradiation was carriedmore » out on the 8th, l0th, or llth day. During this most sensitive developmental stage at 8 1/2 days, 3 to 5 brain vesicles are formed and the anterior neuropore is closed, which may account for the greater effect of teratogenic agents on the central nervous system at this time. Other abnormalities included exencephalia (2%), hydrocephalus (4%), microcephalia (0.7%), abnormally shaped head (5%), spinal cord anomalies (6%), eye anomalies (29%), harelip and cleft palate (l2%), tail abnormalities (6%), and thoraco- abdominal hennia (5%). (H.H.D.)« less

Nuclear Science Symposium, 27th, and Symposium on Nuclear Power Systems, 12th, Orlando, Fla., November 5-7, 1980, Proceedings

NASA Technical Reports Server (NTRS)

Martini, M.

1981-01-01

Advances in instrumentation for use in nuclear-science studies are described. Consideration is given to medical instrumentation, computerized fluoroscopy, environmental instrumentation, data acquisition techniques, semiconductor detectors, microchannel plates and photomultiplier tubes, reactor instrumentation, neutron detectors and proportional counters, and space instrumentation.

National Leaders in Innovation. Washington's Community and Technical Colleges

ERIC Educational Resources Information Center

Washington State Board for Community and Technical Colleges, 2015

2015-01-01

Washington's community and technical colleges set a national example for innovative policies, practices and research for student success. Washington's community and technical college system ranks 12th in the nation for graduation rates, and 7th for certificates and degrees produced. Olympic College and Renton Technical College in March 2015 were…

Advanced Electronics. Curriculum Development. Bulletin 1778.

ERIC Educational Resources Information Center

Eppler, Thomas

This document is a curriculum guide for a 180-hour course in advanced electronics for 11th and 12th grades that has four instructional units. The instructional units are orientation, discrete components, integrated circuits, and electronic systems. The document includes a course flow chart; a two-page section that describes the course, lists…

Controlling the Degradation of Bioresorbable Polymers

NASA Astrophysics Data System (ADS)

Moritz, Istvan; Crowley, Brian; Brundage, Elizabeth; Rende, Deniz; Ozisik, Rahmi

Bioresorbable polymers play a vital role in the development of implantable materials that are used in surgical procedures, controlled drug delivery systems; and tissue engineering scaffolds. The half-life of common bioresorbable polymers ranges from 3 to over 12 months and slow bioresorption rates of these polymers restrict their use to a limited set of applications. The use of embedded enzymes was previously proposed to control the degradation rate of bioresorbable polymers, and was shown to decrease average degradation time to about 0.5 months. In this study, electromagnetic actuation of iron oxide magnetic nanoparticles embedded in an encapsulant polymer, poly(ethyleneoxide), PEO, was employed to initiate enzyme assisted degradation of bioresorbable polymer poly(caprolactone), PCL. Results indicate that the internal temperature of iron oxide magnetic nanoparticle doped PEO samples can be increased via an alternating magnetic field, and temperature increase depends strongly on nanoparticle concentration and magnetic field parameters. The temperature achieved is sufficient to relax the PEO matrix and to enable the diffusion of enzymes from PEO to a surrounding PCL matrix. Current studies are directed at measuring the degradation rate of PCL due to the diffused enzyme. This material is based upon work supported by the National Science Foundation under Grant No. CMMI-1538730.

Updateable 3D Display Using Large Area Photorefractive Polymer Devices

DTIC Science & Technology

2013-04-01

across the thin PR layer. The critical parameters for the buffer layer are: transparent over the range 400nm to 800nm, high dielectric strength , ease of...Holographic 3D Display for Telepresence". Holo- pack.Holo- print 2011, November 9th 2011, (Las-Vegas, NV).  J. Thomas et al., "Recent advances in...AFRL-OSR-VA-TR-2013-0199 Updateable 3D Display Using Large Area Photofractive Polymer Devics Pierre Alexandre Blanche TIPD

Mixed Matrix Membranes of Boron Icosahedron and Polymers of Intrinsic Microporosity (PIM-1) for Gas Separation

PubMed Central

Khan, Muntazim Munir; Shishatskiy, Sergey; Filiz, Volkan

2018-01-01

This work reports on the preparation and gas transport performance of mixed matrix membranes (MMMs) based on the polymer of intrinsic microporosity (PIM-1) and potassium dodecahydrododecaborate (K2B12H12) as inorganic particles (IPs). The effect of IP loading on the gas separation performance of these MMMs was investigated by varying the IP content (2.5, 5, 10 and 20 wt %) in a PIM-1 polymer matrix. The derived MMMs were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), single gas permeation tests and sorption measurement. The PIM1/K2B12H12 MMMs show good dispersion of the IPs (from 2.5 to 10 wt %) in the polymer matrix. The gas permeability of PIM1/K2B12H12 MMMs increases as the loading of IPs increases (up to 10 wt %) without sacrificing permselectivity. The sorption isotherm in PIM-1 and PIM1/K2B12H12 MMMs demonstrate typical dual-mode sorption behaviors for the gases CO2 and CH4. PMID:29301312

Polarization of T-helper lymphocytes toward the Th2 phenotype in uremic patients.

PubMed

Libetta, C; Rampino, T; Dal Canton, A

2001-08-01

T-helper (Th) lymphocytes consist of Th1 and Th2 subsets. Th1 cells are effectors of cell-mediated immunity and secrete interferon-gamma (IFN-gamma), which recruits new Th1 cells in cooperation with interleukin-12 (IL-12; produced by monocytes) and inhibits Th2 differentiation. Th2 cells produce IL-4 and IL-10, which inhibit IFN-gamma secretion and cell immunity. We investigated whether the impaired immune response in uremia is associated with an altered balance of Th1/Th2. Peripheral-blood mononuclear cells (PBMCs) were collected from patients with chronic renal failure (CRF) on conservative treatment (CRF patients), patients with end-stage renal disease (ESRD) on regular hemodialysis therapy (ESRD-HD patients), and healthy controls (CON). CD4(+) cells were isolated from PBMCs by negative selection using a magnetic labeling system. PBMCs and purified CD4(+) cells were cultured in Iscove's medium and Iscove's medium plus mitogens (phytohemagglutinin and lipopolysaccharide). IFN-gamma, IL-12, IL-4, and IL-10 were measured in supernatant. The constitutive release of IL-4 and IL-10 by PBMCs and CD4(+) cells of CRF and ESRD-HD patients was increased by five to eight times in comparison with CON (P < 0.001). Constitutive IFN-gamma release by PBMCs of ESRD-HD patients was undetectable, although they secreted an increased amount of IL-12. Mitogen-stimulated release of IFN-gamma by PBMCs and CD4(+) cells of CRF and ESRD-HD patients was blunted (average PBMCs: CON, 115.8 pg/2 x10(6) cells; CRF, 81.8 pg/2 x10(6) cells; ESRD-HD, 9.3 pg/2 x10(6) cells; CD4(+) cells: CON, 358.0 pg/5 x 10(5) cells; CRF, 165.4 pg/5 x 10(5) cells; ESRD-HD, 43.5 pg/5 x 10(5) cells). The ability of PBMCs of ESRD-HD patients to secrete IFN-gamma was recovered after IL-4 and IL-10 neutralization. Uremia is associated with a prevalence of Th1 over Th2 cells and a configuration of cytokine network that depresses cell-mediated immunity.

Pavement performance testing : executive summary.

DOT National Transportation Integrated Search

2001-12-01

The objectives of this study were to evaluate the effects of aggregate gradation and polymer modification on rutting and fatigue resistance of Superpave mixes. Asphalt mixes were prepared using three different gradations (above, through, and below th...

Histogram analysis of diffusion kurtosis imaging estimates for in vivo assessment of 2016 WHO glioma grades: A cross-sectional observational study.

PubMed

Hempel, Johann-Martin; Schittenhelm, Jens; Brendle, Cornelia; Bender, Benjamin; Bier, Georg; Skardelly, Marco; Tabatabai, Ghazaleh; Castaneda Vega, Salvador; Ernemann, Ulrike; Klose, Uwe

2017-10-01

To assess the diagnostic performance of histogram analysis of diffusion kurtosis imaging (DKI) maps for in vivo assessment of the 2016 World Health Organization Classification of Tumors of the Central Nervous System (2016 CNS WHO) integrated glioma grades. Seventy-seven patients with histopathologically-confirmed glioma who provided written informed consent were retrospectively assessed between 01/2014 and 03/2017 from a prospective trial approved by the local institutional review board. Ten histogram parameters of mean kurtosis (MK) and mean diffusivity (MD) metrics from DKI were independently assessed by two blinded physicians from a volume of interest around the entire solid tumor. One-way ANOVA was used to compare MK and MD histogram parameter values between 2016 CNS WHO-based tumor grades. Receiver operating characteristic analysis was performed on MK and MD histogram parameters for significant results. The 25th, 50th, 75th, and 90th percentiles of MK and average MK showed significant differences between IDH1/2 wild-type gliomas, IDH1/2 mutated gliomas, and oligodendrogliomas with chromosome 1p/19q loss of heterozygosity and IDH1/2 mutation (p<0.001). The 50th, 75th, and 90th percentiles showed a slightly higher diagnostic performance (area under the curve (AUC) range; 0.868-0.991) than average MK (AUC range; 0.855-0.988) in classifying glioma according to the integrated approach of 2016 CNS WHO. Histogram analysis of DKI can stratify gliomas according to the integrated approach of 2016 CNS WHO. The 50th (median), 75th , and the 90th percentiles showed the highest diagnostic performance. However, the average MK is also robust and feasible in routine clinical practice. Copyright © 2017 Elsevier B.V. All rights reserved.

A novel acute HIV infection staging system based on 4th generation immunoassay.

PubMed

Ananworanich, Jintanat; Fletcher, James L K; Pinyakorn, Suteeraporn; van Griensven, Frits; Vandergeeten, Claire; Schuetz, Alexandra; Pankam, Tippawan; Trichavaroj, Rapee; Akapirat, Siriwat; Chomchey, Nitiya; Phanuphak, Praphan; Chomont, Nicolas; Michael, Nelson L; Kim, Jerome H; de Souza, Mark

2013-05-29

Fourth generation (4thG) immunoassay (IA) is becoming the standard HIV screening method but was not available when the Fiebig acute HIV infection (AHI) staging system was proposed. Here we evaluated AHI staging based on a 4thG IA (4thG staging). Screening for AHI was performed in real-time by pooled nucleic acid testing (NAT, n=48,828 samples) and sequential enzyme immunoassay (EIA, n=3,939 samples) identifying 63 subjects with non-reactive 2nd generation EIA (Fiebig stages I (n=25), II (n=7), III (n=29), IV (n=2)). The majority of samples tested (n=53) were subtype CRF_01AE (77%). NAT+ subjects were re-staged into three 4thG stages: stage 1 (n=20; 4th gen EIA-, 3rd gen EIA-), stage 2 (n=12; 4th gen EIA+, 3rd gen EIA-), stage 3 (n=31; 4th gen EIA+, 3rd gen EIA+, Western blot-/indeterminate). 4thG staging distinguishes groups of AHI subjects by time since presumed HIV exposure, pattern of CD8+ T, B and natural killer cell absolute numbers, and HIV RNA and DNA levels. This staging system further stratified Fiebig I subjects: 18 subjects in 4thG stage 1 had lower HIV RNA and DNA levels than 7 subjects in 4thG stage 2. Using 4th generation IA as part of AHI staging distinguishes groups of patients by time since exposure to HIV, lymphocyte numbers and HIV viral burden. It identifies two groups of Fiebig stage I subjects who display different levels of HIV RNA and DNA, which may have implication for HIV cure. 4th generation IA should be incorporated into AHI staging systems.

Effect of surface modification of fibers with a polymer coating on the interlaminar shear strength of a composite and the translation of fiber strength in an F-12 aramid/epoxy composite vessel

NASA Astrophysics Data System (ADS)

Shu-hui, Zhang; Guo-zheng, Liang; Wei, Zhang; Jin-fang, Zeng

2006-11-01

The surface of aramid fibers was modified with a polymer coating — a surface treatment reagent containing epoxy resin. The resulting fibers were examined by using NOL tests, hydroburst tests, and the scanning electron microscopy. The modified fibers had a rougher surface than the untreated ones. The interlaminar shear strength of an aramid-fiber-reinforced epoxy composite was highest when the concentration of polymer coating system was 5%. The translation of fiber strength in an aramid/epoxy composite vessel was improved by 8%. The mechanism of the surface treatment of fibers in improving the mechanical properties of aramid/epoxy composites is discussed.

A case of systemic lupus erythematosus presenting transverse myelitis after an episode of meningitis.

PubMed

Yago, Toru; Tateishi, Mutsuto; Ichikawa, Naomi; Furuya, Takefumi; Sakurai, Tadashi; Nakajima, Hiroshi; Hara, Masako; Kamatani, Naoyuki

2005-01-01

A 27-year-old woman suffering from systemic lupus erythematosus was admitted because she had motor and sensory palsy of the lower extremities, neck stiffness, and a fever. Cerebrospinal fluid study indicated meningitis, and magnetic resonance imaging revealed cord swelling and high signals at Th9-Th12 levels. Antibiotics treatment led to resolution of the meningeal signs. Intravenous cyclophosphamide and prednisolone resulted in a partial recovery from the transverse myelitis neurological disturbance.

International Conference on Deformation, Yield and Fracture of Polymers (9th) Held in Cambridge, UK on 11-14 April, 1994. Conference Papers

DTIC Science & Technology

1994-01-01

microplasticity and relaxations in polymers using a laser interferometer NN Peschanskaya, PN Yakushev, AB Sinani and VA Bershtein (Ioffe Physical-Technical...Medicine, London, UK) P29 Toughening mechanism of flame-retarded plastics L Utevskii, I Finberg, E Reznik and M Muskatel (Dead Sea Bromine group, Beer...Dead Sea Bromine Group, Beer Sheva, Israel) P31 Stress-relaxation due to environmental effects on polypropylene and fiber reinforced polyester E Gutman

Ultrafast polarisation spectroscopy of photoinduced charges in a conjugated polymer

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

Bakulin, A A; Loosdrecht, P van; Pshenichnikov, M S

2009-07-31

Tunable optical parametric generators and amplifiers (OPA), proposed and developed by Akhmanov and his colleagues, have become the working horses in exploration of dynamical processes in physics, chemistry, and biology. In this paper, we demonstrate the possibility of using ultrafast polarisation-sensitive two-colour spectroscopy, performed with a set of two OPAs, to study charge photogeneration and transport in conjugated polymers and their donor-acceptor blends. (special issue devoted to the 80th birthday of S.A. Akhmanov)

Amityville Memorial High School History Journal Advance Placement History.

ERIC Educational Resources Information Center

Howlett, Charles F., Ed.

The history of Amityville, New York, compiled by 11th and 12th grade advance placement history students, is presented in journal form. Six papers focus on: (1) South Oaks: The Long Island Home; (2) A History of Bethel African Methodist Episcopal Church, Amityville; (3) Amityville: A Vacationland; (4) Amityville School System from 1904 to Present;…

Synthesis, Characterisation, and Evaluation of a Cross-Linked Disulphide Amide-Anhydride-Containing Polymer Based on Cysteine for Colonic Drug Delivery

PubMed Central

Lim, Vuanghao; Peh, Kok Khiang; Sahudin, Shariza

2013-01-01

The use of disulphide polymers, a low redox potential responsive delivery, is one strategy for targeting drugs to the colon so that they are specifically released there. The objective of this study was to synthesise a new cross-linked disulphide-containing polymer based on the amino acid cysteine as a colon drug delivery system and to evaluate the efficiency of the polymers for colon targeted drug delivery under the condition of a low redox potential. The disulphide cross-linked polymers were synthesised via air oxidation of 1,2-ethanedithiol and 3-mercapto-N-2-(3-mercaptopropionamide)-3-mercapto propionic anhydride (trithiol monomers) using different ratio combinations. Four types of polymers were synthesised: P10, P11, P151, and P15. All compounds synthesised were characterised by NMR, IR, LC-MS, CHNS analysis, Raman spectrometry, SEM-EDX, and elemental mapping. The synthesised polymers were evaluated in chemical reduction studies that were performed in zinc/acetic acid solution. The suitability of each polymer for use in colon-targeted drug delivery was investigated in vitro using simulated conditions. Chemical reduction studies showed that all polymers were reduced after 0.5–1.0 h, but different polymers had different thiol concentrations. The bacterial degradation studies showed that the polymers were biodegraded in the anaerobic colonic bacterial medium. Degradation was most pronounced for polymer P15. This result complements the general consensus that biodegradability depends on the swellability of polymers in an aqueous environment. Overall, these results suggest that the cross-linked disulphide-containing polymers described herein could be used as coatings for drugs delivered to the colon. PMID:24351841

Anabolic Steroids (For Teens)

MedlinePlus

... left or right to scroll. Monitoring the Future Study: Trends in Prevalence of Steroids for 8th Graders, 10th Graders, and 12th Graders; 2017 (in percent)* Drug Time Period 8th Graders 10th Graders 12th Graders Steroids ...

Small-Angle Neutron Scattering Study of Interplay of Attractive and Repulsive Interactions in Nanoparticle-Polymer System.

PubMed

Kumar, Sugam; Aswal, Vinod K; Kohlbrecher, Joachim

2016-02-16

The phase behavior of nanoparticle (silica)-polymer (polyethylene glycol) system without and with an electrolyte (NaCl) has been studied. It is observed that nanoparticle-polymer system behaves very differently in the presence of electrolyte. In the absence of electrolyte, the nanoparticle-polymer system remains in one-phase even at very high polymer concentrations. On the other hand, a re-entrant phase behavior is found in the presence of electrolyte, where one-phase (individual) system undergoes two-phase (nanoparticle aggregation) and then back to one-phase with increasing polymer concentration. The regime of two-phase system has been tuned by varying the electrolyte concentration. The polymer concentration range over which the two-phase system exists is significantly enhanced with the increase in the electrolyte concentration. These systems have been characterized by small-angle neutron scattering (SANS) experiments of contrast-marching the polymer to the solvent. The data are modeled using a two-Yukawa potential accounting for both attractive and repulsive parts of the interaction between nanoparticles. The phase behavior of nanoparticle-polymer system is explained by interplay of attractive (polymer-induced attractive depletion between nanoparticles) and repulsive (nanoparticle-nanoparticle electrostatic repulsion and polymer-polymer repulsion) interactions present in the system. In the absence of electrolyte, the strong electrostatic repulsion between nanoparticles dominates over the polymer-induced depletion attraction and the nanoparticle system remains in one-phase. With addition of electrolyte, depletion attraction overcomes electrostatic repulsion at some polymer concentration, resulting into nanoparticle aggregation and two-phase system. Further addition of polymer increases the polymer-polymer repulsion which eventually reduces the strength of depletion and hence re-entrant phase behavior. The effects of varying electrolyte concentration on the phase behavior of nanoparticle-polymer system are understood in terms of modifications in nanoparticle-nanoparticle and polymer-polymer interactions. The nanoparticle aggregates in two-phase systems are found to have surface fractal morphology.

Evaluation of water uptake and mechanical properties of blended polymer films for preparing gas-generated multiple-unit floating drug delivery systems.

PubMed

Chen, Ying-Chen; Lee, Lin-Wen; Ho, Hsiu-O; Sha, Chen; Sheu, Ming-Thau

2012-10-01

Among various strategies of gastroretentive drug delivery systems (DDSs) developed to prolong the gastric residence time and to increase the overall bioavailability, effervescent multiple-unit floating DDSs (muFDDSs) were studied here. These systems consist of drug (losartan)- and effervescent (sodium bicarbonate)-containing pellets coated with a blended polymeric membrane, which was a mixture of gastrointestinal tract (GIT)-soluble and GIT-insoluble polymers. The addition of GIT-soluble polymers, such as hydroxypropyl methylcellulose, polyethylene glycol (PEG) 6000, PEG 600, and Kollicoat® IR, greatly increased the water uptake ability of the GIT-insoluble polymers (Eudragit® NE, RS, and RL; Surelease®; and Kollicoat® SR) and caused them to immediately initiate the effervescent reaction and float, but the hydrated films should also be impermeable to the generated CO(2) to maintain floatation and sufficiently flexible to withstand the pressure of carbon dioxide to avoid rupturing. The study demonstrated that the water uptake ability and mechanical properties could be applied as screening tools during the development of effervescent muFDDSs. The optimized system of SRT(5)P600(5) (i.e., a mixture of 5% Kollicoat® SR and 5% PEG 600) with a 20% coating level began to completely float within 15 min and maintained its buoyancy over a period of 12 h with a sustained-release effect. Copyright © 2012 Wiley Periodicals, Inc.

20th JANNAF Propulsion Systems Hazards Subcommittee Meeting. Volume 1

NASA Technical Reports Server (NTRS)

Cocchiaro, James E. (Editor); Eggleston, Debra S. (Editor); Gannaway, Mary T. (Editor); Inzar, Jeanette M. (Editor)

2002-01-01

This volume, the first of two volumes, is a collection of 24 unclassified/unlimited-distribution papers which were presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 20th Propulsion Systems Hazards Subcommittee (PSHS), 38th Combustion Subcommittee (CS), 26th Airbreathing Propulsion Subcommittee (APS), and 21 Modeling and Simulation Subcommittee meeting. The meeting was held 8-12 April 2002 at the Bayside Inn at The Sandestin Golf & Beach Resort and Eglin Air Force Base, Destin, Florida. Topics covered include: insensitive munitions and hazard classification testing of solid rocket motors and other munitions; vulnerability of gun propellants to impact stimuli; thermal decomposition and cookoff properties of energetic materials; burn-to-violent reaction phenomena in energetic materials; and shock-to-detonation properties of solid propellants and energetic materials.

Joint Air-to-Surface Standoff Missile (JASSM)

DTIC Science & Technology

2015-12-01

6.1.3) All Ops All Ops Joint Critical Ops All Ops All Ops Missile Reliability (KSA) (CPD para 6.2.8) 4th Lot .91 4th Lot .91 IOT &E .80 4th Lot .85 IOT &E...the ORD 303-95-III dated January 20, 2004 Change Explanations None Acronyms and Abbreviations IOT &E - Initial Operational Test and Evaluation KSA... Actuator Control Card, Lots 12 and 4 Systems Engineering Program Support/Program Tooling and Test Equipment, and JASSM-ER Standard Data Protocol (DS

What are kids vaping? Results from a national survey of US adolescents.

PubMed

Miech, Richard; Patrick, Megan E; O'Malley, Patrick M; Johnston, Lloyd D

2017-07-01

To examine what substances US youth vape. Data come from Monitoring the Future, an annual, nationally representative survey of USA 12th-grade, 10th-grade and 8th-grade students. Respondents reported what substance they vaped the last time they used a vaporiser such as an e-cigarette. Among students who had ever used a vaporiser, 65-66% last used 'just flavouring' in 12th, in 10th and in 8th grade, more than all other responses combined. In all three grades, the percentage using 'just flavouring' was above 57% for males, females, African-Americans, Hispanics, Whites, and students both with and without a parent with a college degree. Nicotine use came in a distant second, at about 20% in 12th and 10th grade and 13% in 8th grade. Taking into account youth who vaped nicotine at last use increases national estimates of tobacco/nicotine prevalence in the past 30 days by 24-38% above and beyond cigarette smoking, which is substantial but far less than estimates that assume all vaporiser users inhale nicotine. These results challenge the common assumption that all vaporiser users inhale nicotine. They (a) call into question the designation of vaporisers and e-cigarettes as ENDS ('Electronic Nicotine Delivery System'), (b) suggest that the recent rise in adolescent vaporiser use does not necessarily indicate a nicotine epidemic, and (c) indicate that vaporiser users can be candidates for primary prevention programmes. Finally, the results suggest the importance of developing different rationales for the regulation of vaporiser devices as compared to the regulation of substances marketed for vaporiser use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Monogamy of αth power entanglement measurement in qubit systems

NASA Astrophysics Data System (ADS)

Luo, Yu; Li, Yongming

2015-11-01

In this paper, we study the αth power monogamy properties related to the entanglement measure in bipartite states. The monogamy relations related to the αth power of negativity and the Convex-Roof Extended Negativity are obtained for N-qubit states. We also give a tighter bound of hierarchical monogamy inequality for the entanglement of formation. We find that the GHZ state and W state can be used to distinguish both the αth power of the concurrence for 0 < α < 2 and the αth power of the entanglement of formation for 0 < α ≤ 1/2. Furthermore, we compare concurrence with negativity in terms of monogamy property and investigate the difference between them.

Functionalized Polymeric Materials for Electronics and Optics

DTIC Science & Technology

1993-05-31

some of the physical characteristics of the photocrosslinkable systems derived from a cinnamate functionalized NLO-dye and the photoreactive polymers...chromophore. Figure 12.12 is a UV-Vis spectrum of polyvinyl cinnamate film doped with 10% of the cross-linkable NLO azo dye CNNB-R. The spectrum for the poled...can be similarly prepared from aqueous solutions containing aniline and hydrochloric or sulfuric acids . A very useful review of synthetic methods for

Coupling the Alkaline-Surfactant-Polymer Technology and The Gelation Technology to Maximize Oil Production

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

Malcolm Pitts; Jie Qi; Dan Wilson

2005-10-01

Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A priormore » fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent alkaline-surfactant-polymer injected solution were observed. Aluminum citrate-polyacrylamide, resorcinol-formaldehyde, and the silicate-polyacrylamide gel systems did not produce significant incremental oil in linear corefloods. Both flowing and rigid flowing chromium acetate-polyacrylamide gels and the xanthan gum-chromium acetate gel system produced incremental oil with the rigid flowing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. None of the gels tested appeared to alter alkaline-surfactant-polymer solution oil recovery. Total waterflood plus chemical flood oil recovery sequence recoveries were all similar. Chromium acetate-polyacrylamide gel used to seal fractured core maintain fracture closure if followed by an alkaline-surfactant-polymer solution. Chromium acetate gels that were stable to injection of alkaline-surfactant-polymer solutions at 72 F were stable to injection of alkaline-surfactant-polymer solutions at 125 F and 175 F in linear corefloods. Chromium acetate-polyacrylamide gels maintained diversion capability after injection of an alkaline-surfactant-polymer solution in stacked; radial coreflood with a common well bore. Xanthan gum-chromium acetate gels maintained gel integrity in linear corefloods after injection of an alkaline-surfactant-polymer solution at 125 F. At 175 F, Xanthan gum-chromium acetate gels were not stable either with or without subsequent alkaline-surfactant-polymer solution injection. Numerical simulation demonstrated that reducing the permeability of a high permeability zone of a reservoir with gel improved both waterflood and alkaline-surfactant-polymer flood oil recovery. A Minnelusa reservoir with both A and B sand production was simulated. A and B sands are separated by a shale layer. A sand and B sand waterflood oil recovery was improved by 196,000 bbls when a gel was placed in the B sand. A sand and B sand alkaline-surfactant-polymer flood oil recovery was improved by 596,000 bbls when a gel was placed in the B sand. Alkaline-surfactant-polymer flood oil recovery improvement over a waterflood was 392,000 bbls. Placing a gel into the B sand prior to an alkaline-surfactant-polymer flood resulted in 989,000 bbl more oil than only water injection.« less

Ultrathin, bioresorbable polymer sirolimus-eluting stents versus thin, durable polymer everolimus-eluting stents in patients undergoing coronary revascularisation (BIOFLOW V): a randomised trial.

PubMed

Kandzari, David E; Mauri, Laura; Koolen, Jacques J; Massaro, Joseph M; Doros, Gheorghe; Garcia-Garcia, Hector M; Bennett, Johan; Roguin, Ariel; Gharib, Elie G; Cutlip, Donald E; Waksman, Ron

2017-10-21

The development of coronary drug-eluting stents has included use of new metal alloys, changes in stent architecture, and use of bioresorbable polymers. Whether these advancements improve clinical safety and efficacy has not been shown in previous randomised trials. We aimed to examine the clinical outcomes of a bioresorbable polymer sirolimus-eluting stent compared with a durable polymer everolimus-eluting stent in a broad patient population undergoing percutaneous coronary intervention. BIOFLOW V was an international, randomised trial done in patients undergoing elective and urgent percutaneous coronary intervention in 90 hospitals in 13 countries (Australia, Belgium, Canada, Denmark, Germany, Hungary, Israel, the Netherlands, New Zealand, South Korea, Spain, Switzerland, and the USA). Eligible patients were those aged 18 years or older with ischaemic heart disease undergoing planned stent implantation in de-novo, native coronary lesions. Patients were randomly assigned (2:1) to either an ultrathin strut (60 μm) bioresorbable polymer sirolimus-eluting stent or to a durable polymer everolimus-eluting stent. Randomisation was via a central web-based data capture system (mixed blocks of 3 and 6), and stratified by study site. The primary endpoint was 12-month target lesion failure. The primary non-inferiority comparison combined these data from two additional randomised trials of bioresorbable polymer sirolimus-eluting stent and durable polymer everolimus-eluting stent with Bayesian methods. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT02389946. Between May 8, 2015, and March 31, 2016, 4772 patients were recruited into the study. 1334 patients met inclusion criteria and were randomly assigned to treatment with bioresorbable polymer sirolimus-eluting stents (n=884) or durable polymer everolimus-eluting stents (n=450). 52 (6%) of 883 patients in the bioresorbable polymer sirolimus-eluting stent group and 41 (10%) of 427 patients in the durable polymer everolimus-eluting stent group met the 12-month primary endpoint of target lesion failure (95% CI -6·84 to -0·29, p=0·0399), with differences in target vessel myocardial infarction (39 [5%] of 831 patients vs 35 [8%] of 424 patients, p=0·0155). The posterior probability that the bioresorbable polymer sirolimus-eluting stent is non-inferior to the durable polymer everolimus-eluting stent was 100% (Bayesian analysis, difference in target lesion failure frequency -2·6% [95% credible interval -5·5 to 0·1], non-inferiority margin 3·85%, n=2208). The outperformance of the ultrathin, bioresorbable polymer sirolimus-eluting stent over the durable polymer everolimus-eluting stent in a complex patient population undergoing percutaneous coronary intervention suggests a new direction in improving next generation drug-eluting stent technology. BIOTRONIK. Copyright © 2017 Elsevier Ltd. All rights reserved.

Alkali Salt-Doped Highly Transparent and Thickness-Insensitive Electron-Transport Layer for High-Performance Polymer Solar Cell.

PubMed

Xu, Rongguo; Zhang, Kai; Liu, Xi; Jin, Yaocheng; Jiang, Xiao-Fang; Xu, Qing-Hua; Huang, Fei; Cao, Yong

2018-01-17

Solution-processable highly transparent and thickness-insensitive hybrid electron-transport layer (ETL) with enhanced electron-extraction and electron-transport properties for high-performance polymer solar cell was reported. With the incorporation of Cs 2 CO 3 into the poly[(9,9-bis(6'-((N,N-diethyl)-N-ethylammonium)-hexyl)-2,7-fluorene)-alt-1,4-diphenylsulfide]dibromide (PF6NPSBr) ETL, the power conversion efficiency (PCE) of resulted polymer solar cells (PSCs) was significantly enhanced due to the favorable interfacial contact, energy-level alignment, and thus facile electron transport in the PSC device. These organic-inorganic hybrid ETLs also exhibited high transparency and high electron mobility. All of these combined properties ensured us to design novel thickness-insensitive ETLs that avoid the parasitic absorption of ETL itself simultaneously. With the conventional device structure with poly{4,8-bis[5-(2-ethylhexyl)thiophen-2-yl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl} (PTB7-Th) as a donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM) as an acceptor, devices with hybrid ETLs exhibited PCE of 8.30-9.45% within a wide range of ETL thickness. A notable PCE of 10.78% was achieved with the thick active layer poly(2,5-thiophene-alt-5,5'-(5,10-bis(4-(2-octyldodecyl)thiophen-2-yl)naphtho[1,2-c:5,6-c']bis([1,2,5]thiadiazole)) (PTNT812):PC 71 BM. These findings indicated that doping alkali salt into the organic interfacial materials can be a promising strategy to design highly efficient and thickness-insensitive ETL, which may be suitable for large-area PSC modules device fabrication with roll-to-roll printing technique.

Laser direct writing of complex radially varying single-mode polymer waveguide structures

NASA Astrophysics Data System (ADS)

Kruse, Kevin; Peng, Jie; Middlebrook, Christopher T.

2015-07-01

Increasing board-to-board and chip-to-chip computational data rates beyond 12.5 Gbs will require the use of single-mode polymer waveguides (WGs) that have high bandwidths and are able to be wavelength division multiplexed. Laser direct writing (LDW) of polymer WGs provides a scalable and reconfigurable maskless procedure compared to common photolithography fabrication. LDW of straights and radial curves are readily achieved using predefined drive commands of the two-axis direct drive linear stage system. Using the laser direct write process for advanced WG structures requires stage-drive programming techniques that account for specified polymer material exposure durations. Creating advanced structures such as WG S-bends into single-mode polymer WG builds provides designers with the ability to affect pitch control, optical coupling, and reduce footprint requirements. Fabrication of single-mode polymer WG segmented radial arcs is achieved through a smooth radial arc user-programmed defined mathematical algorithm. Cosine and raised-sine S-bends are realized through a segmentation method where the optimal incremental step length and bend dimensions are controlled to achieve minimal structure loss. Laser direct written S-bends are compared with previously published photolithographic S-bend results using theoretical bend loss models. Fabrication results show that LDW is a viable method in the fabrication of advanced polymer WG structures.

A STUDY OF THE MECHANISM OF RADIATION-INDUCED GELATION IN MONOMER-POLYMER MIXTURES. Quarterly Summary Report, August 1, 1961-October 31, 1961

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

Odian, G.; Bernstein, B.S.; Kelly, J.J.

1961-11-01

Gel contents can be obtained with polyethylene swollen with inhibitor- free allyl acrylate or inhibitor-free allyl methacrylate at a dose of only 0.05 Mrads Using Co/sup 60/ as the radiation source, allyl methacrylate gives higher gel content than allyl acrylate under similar conditions. icant and continues after Co/sup 60/ irradiation has been completed. Monomer desorption after a dose of 1.2 Mrads is less than after 0.05 Mrads, and does not continue after irradiation is stopped. Gel contents can be obtained without prior equilibrium swelling of polymer--monomer mixtures by irradiating the polymer in the presence of the monomer in a nitrogenmore » atmosphere. By irradiating under these conditions with prior equilibrium swelling, gel fractions appear to be higher than those normally obtained. Gel contents of irradiated equilibrium-swollen polyethylene/ allyl acrylate and polyethylene/allyl methacrylate increase with increasing radiation dose from 0.05 to 1.2 Mrads. Gel contents of 1.2 Mrad irradiated polyethyleneallyl methacrylate systems containing various initial amounts of monomer, increase with increasing monomer content. Polypropylene can be radiation crosslinked to give over 40% gel by prior equilibrium swelling with allyl acrylate or allyl methacrylate. (auth)« less

Youth Risk Behavior Surveillance System: Selected 2011 National Health Risk Behaviors and Health Outcomes by Sex

ERIC Educational Resources Information Center

Centers for Disease Control and Prevention, 2011

2011-01-01

The national Youth Risk Behavior Survey (YRBS) monitors priority health risk behaviors that contribute to the leading causes of death, disability, and social problems among youth and adults in the United States. The national YRBS is conducted every two years during the spring semester and provides data representative of 9th through 12th grade…

An Exploratory Study of School-Age Children's Use of a Heterogeneous Resource Site

ERIC Educational Resources Information Center

Holmes, Jason; Robins, David; Zhang, Yin; Salaba, Athena

2008-01-01

In this study, students' use of a new educational Web portal was evaluated with particular emphasis on searching and browsing strategies. The effects and implications of a federated search system are also discussed. Fifty-four students, ranging from 5th to 12th grade, were given five tasks to complete using the SchoolRooms interface. The tasks…

Novel therapy for pyridoxine dependent epilepsy due to ALDH7A1 genetic defect: L-arginine supplementation alternative to lysine-restricted diet.

PubMed

Mercimek-Mahmutoglu, Saadet; Cordeiro, Dawn; Cruz, Vivian; Hyland, Keith; Struys, Eduard A; Kyriakopoulou, Lianna; Mamak, Eva

2014-11-01

Pyridoxine dependent epilepsy (PDE) due to mutations in the ALDH7A1 gene (PDE-ALDH7A1) is caused by α-aminoadipic-semialdehyde-dehydrogenase enzyme deficiency in the lysine pathway resulting in the accumulation of α-aminoadipic acid semialdehyde (α-AASA). Classical presentation is neonatal intractable seizures with a dramatic response to pyridoxine. Pyridoxine therapy does not prevent developmental delays in the majority of the patients. We hypothesized that L-arginine supplementation will decrease accumulation of α-AASA by competitive inhibition of lysine transport into the central nervous system and improve neurodevelopmental and neurocognitive functions in PDE-ALDH7A1. A 12-year-old male with PDE-ALDH7A1 was treated with l-arginine supplementation as an innovative therapy. Treatment outcome was monitored by cerebral-spinal-fluid (CSF) α-AASA measurements at baseline, 6th and 12th months of therapy. Neuropsychological assessments were performed at baseline and 12th months of therapy. L-arginine therapy was well tolerated without side effects. CSF α-AASA was decreased 57% at 12th months of therapy. Neuropsychological assessments revealed improvements in general abilities index from 108 to 116 and improvements in verbal and motor functioning at 12th months of therapy. The short-term treatment outcome of this novel L-arginine supplementation therapy for PDE-ALDH7A1 was successful for biochemical and neurocognitive improvements. Copyright © 2014 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

THE EMISSION PROCESSING SYSTEM FOR THE ETA/CMAQ AIR QUALITY FORECAST SYSTEM

EPA Science Inventory

NOAA and EPA have created an Air Quality Forecast (AQF) system. This AQF system links an adaptation of the EPA's Community Multiscale Air Quality Model with the 12 kilometer ETA model running operationally at NOAA's National Center for Environmental Predication (NCEP). One of th...

Characterization of the Physicochemical Properties of β-Cyclodextrin-Divinyl Sulfone Polymer Carrier-Bile Acid Systems.

PubMed

Mohamed, Mohamed H; Wang, Chen; Peru, Kerry M; Headley, John V; Wilson, Lee D

2017-08-07

Herein, we report on the systematic design and characterization of cross-linked polymer carriers containing β-cyclodextrin (β-CD) and divinyl sulfone (DVS). The polymer carriers were prepared at variable feed ratios (β-CD-DVS; 1:1, 1:2, 1:3, and 1:6) and characterized using spectroscopy (IR, 1 H solution NMR, and 13 C CP-MAS solids NMR spectroscopy), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and a dye decolorization method using phenolphthalein. Uptake studies were carried out at pH 9.00 for the polymer carriers using single component bile acids (cholic acid, deoxycholic acid, glycodeoxycholic acid, and taurodeoxycholic acid). Equilibrium uptake results were evaluated by the Langmuir isotherm model where variable equilibrium parameters were related to the relative apolar character of the bile acid. The Langmuir model yields a carrier/bile acid binding affinity of ∼10 3 M -1 where the lipophilic inclusion sites of the polymer play a prominent role, while the DVS linker framework sites have a lower adsorption affinity, in accordance with the greater hydrophilic character of such sites.

Proceedings of the Navy Symposium on Aeroballistics (12th) Held at the David Taylor Naval Ship Research and Development Center, Bethesda, Maryland on 12-14 May 1981. Volume I.

DTIC Science & Technology

1981-05-01

hypersonic missiles will require high-lift, low-drag configu- rations with good control effectiveness . Non-circular airframe configurations that...substantial effort to devise cost effective wind tunnel systems. The result has been a number of good systems coupling hardware and computer systems...I lating a center bay, comparison is not good as shown in Figure 12. The effect of the dispenser angle of attack on the submissile aerodynamics is

Formulation and evaluation of non-effervescent floating tablets of losartan potassium.

PubMed

Getyala, Anil; Gangadharappa, H V; Prasad, M Sarat Chandra; Reddy, M Praveen Kumar; Kumar, T M Pramod

2013-10-01

The aim of the work is to modify the solubility and bioavailability of Losartan potassium, by employing noneffervescent floating drug delivery (tablet dosage forms). Non-effervescent systems are a type of floating drug delivery systems, that have been used to boost the gastric residence and the floatation time in the gastro intestinal tract. The study included formulation of floating tablets using polymers like Chitosan and Karaya gum as matrix forming agents. Accurel(®) MP 1000 was used as floating agent. The tablets were prepared by direct compression technique. FTIR, DSC studies conformed that there was no incompatibility between the polymer and the drug. Tablet preformulation parameters were within the Pharmacopoeial limit. Tablet showed zero lag time, contisnuance of buoyancy for >12 h. The tablet showed good in vitro release. Drug release was through swelling and abided by the gellation mechanism. In vivo X-ray studies depicted that tablets continued to float in the GIT for 12 h. Accelerated stability showed that, tablets were stable for over 6 month. Thus the prepared non-effervescent floating tablet of Losartan potassium can be used for the treatment of hypertension for more than 12 h with single dose administration.

The U.S. Air Service in World War I. Volume III. The Battle of St. Mihiel

DTIC Science & Technology

1979-01-01

the greatest possible extent. PRACTICE EXERCISES. The more practice excercises of aerial liaison with infantry that can be carried out, the better. It...Operations Office Operations Report, 17:00, Sept. 11th, 1918. Sept. 12th, 1918. 1. Atmospheric Conditions. Very cloudy and raining intermittently ...American E.F. September 12th, 1918 Operations Report No 12 From: 19 h 00 Sept 11th to 17 h 00 Sept 12th. 1. Atmospheric conditions: Intermittent rain and

40 CFR 721.10533 - Amine-modified urea-formaldehyde polymer (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... polymer (generic). 721.10533 Section 721.10533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10533 Amine-modified urea-formaldehyde polymer (generic). (a) Chemical... as amine-modified urea-formaldehyde polymer (PMN P-12-182) is subject to reporting under this section...

40 CFR 721.10533 - Amine-modified urea-formaldehyde polymer (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... polymer (generic). 721.10533 Section 721.10533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10533 Amine-modified urea-formaldehyde polymer (generic). (a) Chemical... as amine-modified urea-formaldehyde polymer (PMN P-12-182) is subject to reporting under this section...

40 CFR 721.10624 - Dicyclohexylmethane-4,4'-diisocyanate, polymer with ethoxylated, propoxylated polyethers (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

..., polymer with ethoxylated, propoxylated polyethers (generic). 721.10624 Section 721.10624 Protection of...,4'-diisocyanate, polymer with ethoxylated, propoxylated polyethers (generic). (a) Chemical substance... dicyclohexylmethane-4,4'-diisocyanate, polymer with ethoxylated, propoxylated polyethers (PMN P-12-326) is subject to...

40 CFR 721.10624 - Dicyclohexylmethane-4,4'-diisocyanate, polymer with ethoxylated, propoxylated polyethers (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

..., polymer with ethoxylated, propoxylated polyethers (generic). 721.10624 Section 721.10624 Protection of...,4'-diisocyanate, polymer with ethoxylated, propoxylated polyethers (generic). (a) Chemical substance... dicyclohexylmethane-4,4'-diisocyanate, polymer with ethoxylated, propoxylated polyethers (PMN P-12-326) is subject to...

Evaluation of the two-way coupled WRF-CMAQ modeling system to the 2011 DISCOVER-AQ campaign at 12-km, 4-km and 1-km resolutions

EPA Science Inventory

At the 12th Annual CMAS Conference initial results from the application of the coupled WRF-CMAQ modeling system to the 2011 Baltimore-Washington D.C. DISCOVER-AQ campaign were presented, with the focus on updates and new methods applied to the WRF modeling for fine-scale applicat...

Too much of a good thing? How breadth of extracurricular participation relates to school-related affect and academic outcomes during adolescence.

PubMed

Knifsend, Casey A; Graham, Sandra

2012-03-01

Although adolescents often participate in multiple extracurricular activities, little research has examined how the breadth of activities in which an adolescent is involved relates to school-related affect and academic performance. Relying on a large, multi-ethnic sample (N = 864; 55.9% female), the current study investigated linear and non-linear relationships of 11th grade activity participation in four activity domains (academic/leadership groups, arts activities, clubs, and sports) to adolescents' sense of belonging at school, academic engagement, and grade point average, contemporarily and in 12th grade. Results of multiple regression models revealed curvilinear relationships for sense of belonging at school in 11th and 12th grade, grade point average in 11th grade, and academic engagement in 12th grade. Adolescents who were moderately involved (i.e., in two domains) reported a greater sense of belonging at school in 11th and 12th grade, a higher grade point average in 11th grade, and greater academic engagement in 12th grade, relative to those who were more or less involved. Furthermore, adolescents' sense of belonging at school in 11th grade mediated the relationship of domain participation in 11th grade to academic engagement in 12th grade. This study suggests that involvement in a moderate number of activity domains promotes positive school-related affect and greater academic performance. School policy implications and recommendations are discussed.

Excellent Long-Term Stability of Power Conversion Efficiency in Non-Fullerene-Based Polymer Solar Cells Bearing Tricyanovinylene-Functionalized n-Type Small Molecules.

PubMed

Ko, Eun Yi; Park, Gi Eun; Lee, Ji Hyung; Kim, Hyung Jong; Lee, Dae Hee; Ahn, Hyungju; Uddin, Mohammad Afsar; Woo, Han Young; Cho, Min Ju; Choi, Dong Hoon

2017-03-15

New small molecules having modified acceptor strength and π-conjugation length and containing dicyanovinylene (DCV) and tricyanovinylene (TCV) as a strongly electron-accepting unit with indacenodithiophene, IDT(DCV) 2 , IDT(TCV) 2 , and IDTT(TCV) 2 , were synthesized and studied in terms of their applicability to polymer solar cells with PTB7-Th as an electron-donating polymer. Intriguingly, the blended films containing IDT(TCV) 2 and IDTT(TCV) 2 exhibited superior shelf life stabilities of more than 1000 h without any reduction in the initial power conversion efficiency. The low-lying lowest unoccupied molecular orbital energy levels and robust internal morphologies of small TCV-containing molecules could afford excellent shelf life stability.

Structural Modifications and Photophysical Studies of Fluorescent Conjugated Polymers for Solid State Sensor Development

NASA Astrophysics Data System (ADS)

Chen, Anting

Fluorescent conjugated polymers (FCPs) represent an exciting area of research in chemosensors and biosensors. Previously, the polymer tmeda-PPETE, N,N,N'-trimethylethylenediamino (tmeda) receptors on a poly[2,5-thiophenediyl-1,2-ethynediyl-1,4-phenylenediyl-1,2-ethynediyl] (PPETE) backbone, showed significant quenching when copper(II) was added. Tmeda-PPETE polymer preloaded with copper(II) was found to be a fluorescent "turn-on" sensor for iron cations. Additional investigation of this metallopolymer revealed a selective sensory system toward carbonate and phosphorus anions through a competitive binding of copper(II) between the polymer tmeda-PPETE and the anions. Fluorescent turn-on response under systematically varied pH was affected by the equilibrium shift of the ionization of polyprotic ions. A sterically hindered pentiptycene group was introduced to the PPETE polymer backbone aiming to reduce aggregation and self-quenching in the solid state. A new FCP, tmeda-PPpETE (poly[(pentiptycene ethynylene)-alt-(thienylene ethynylene)] with tmeda receptors, has been designed and synthesized via Sonogashira cross-coupling reaction. Absorption and emission spectra of tmeda-PPpETE showed blue shifting from tmeda-PPETE, suggesting increased rigidity of polymer backbone. Tmeda-PPpETE showed a high selectivity towards copper(II) with improved sensitivity compared to tmeda-PPETE. The fluorescent quenching response is over 120-fold at emission maximum, and the detection limit is 1.04 ppb, significantly lower than the EPA action level of 1.3 ppm for copper(II). A small turn-off fluorescent response of tmeda-PPpETE was also observed upon addition of iron cations. To further investigate the interaction between pentiptycene containing polymers and iron cations, tmpda-PPpETE containing N,N,N'-trimethylpropylenediamino (tmpda) receptors was designed and synthesized. The absorption and emission spectra for tmpda-PPpETE were analogous to those of tmeda-PPpETE, with a higher quantum yield for tmpda-PPpETE. The cation selectivity test in solution showed selective fluorescent quenching for iron cations. Investigation of the polymer-iron interaction showed that two binding mechanisms were involved. This is the first report of pentiptycene-derived polymer participating in a metal complex formation. By using 1,3,5-triethynylbenzene as the linker group, a network of PPETE polymer backbone loaded with tmeda receptors was designed and synthesized. This transformed the linear FCP, tmeda-PPETE into a network polymer. Two derivatives of this polymer were also successfully synthesized. The metal cation selectivity test showed similar fluorescent response as tmeda-PPETE, which revealed the potential in developing solid state sensors.

Using Polymer Semiconductors and a 3-in-1 Plastic Electronics STEM Education Kit to Engage Students in Hands-On Polymer Inquiry Activities

ERIC Educational Resources Information Center

Enlow, Jessica L.; Marin, Dawn M.; Walter, Michael G.

2017-01-01

To improve polymer education for 9-12 and undergraduate students, a plastic electronics laboratory kit using polymer semiconductors has been developed. The three-module kit and curriculum use polymer semiconductors to provide hands-on inquiry activities with overlapping themes of electrical conductivity, light emission, and light-harvesting solar…

12 CFR 261.10 - Published information.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Publications Services, Board of Governors of the Federal Reserve System, 20th Street and Constitution Avenue, N... Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM...; Procedures for Requests § 261.10 Published information. (a) Federal Register. The Board publishes in the...

Longitudinal Study of Career Cluster Persistence from 8th Grade to 12th Grade with a Focus on the Science, Technology, Engineering, & Math Career Cluster

NASA Astrophysics Data System (ADS)

Wagner, Judson

Today's technology driven global economy has put pressure on the American education system to produce more students who are prepared for careers in Science, Technology, Engineering, and Math (STEM). Adding to this pressure is the demand for a more diverse workforce that can stimulate the development of new ideas and innovation. This in turn requires more female and under represented minority groups to pursue future careers in STEM. Though STEM careers include many of the highest paid professionals, school systems are dealing with exceptionally high numbers of students, especially female and under represented minorities, who begin but do not persist to STEM degree completion. Using the Expectancy-Value Theory (EVT) framework that attributes student motivation to a combination of intrinsic, utility, and attainment values, this study analyzed readily available survey data to gauge students' career related values. These values were indirectly investigated through a longitudinal approach, spanning five years, on the predictive nature of 8 th grade survey-derived recommendations for students to pursue a future in a particular career cluster. Using logistic regression analysis, it was determined that this 8 th grade data, particularly in STEM, provides significantly high probabilities of a 12th grader's average grade, SAT-Math score, the math and science elective courses they take, and most importantly, interest in the same career cluster.

Bilateral sacrospinous fixation without hysterectomy: 18-month follow-up

PubMed Central

Şentürk, Mehmet Baki; Güraslan, Hakan; Çakmak, Yusuf; Ekin, Murat

2015-01-01

Objective The aim of this study was to evaluate the results of bilateral sacrospinous fixation (SSF), which was performed with surgical mesh interposition and bilateral vaginal repair. Material and Methods Twenty-two patients underwent SSF between 2010 and 2012, and the results were evaluated retrospectively. The results at preoperative and postoperative 6th, 12th, and 18th months of the pelvic organ prolapse quantification system (POP-Q) and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire-12 (PISQ-12) were compared using Friedman and Wilcoxon Signed Ranks tests. Values of p<0.05 and <0.01 were considered statistically significant. Results According to the POP-Q, significant healing was observed on all vaginal vault points (p=0.001), and no prolapse was observed until the 18-month follow-up stage. There were also prominent patients who felt satisfactory with respect to their sexual life according to PISQ-12 (p=0.001). Conclusion This technique appears to provide an adequate clinical resolution, and it may be the primary surgical option for women with pelvic organ prolapse. PMID:26097393

NERVA turbopump bearing retainer fabrication on nonmetallic retainer

NASA Technical Reports Server (NTRS)

Accinelli, J. B.

1972-01-01

The need for a low-wear, lightweight, high strength bearing retainer material with a radiation degradation threshold of 10 to the 9th power rads (C) prompted development of nonmetallic reinforced polymers of the following types: (1) polybenzimidazole, (2) polyimide, and (3) polyquinoxaline. Retainers were machined from tubular laminates (billets), including reinforcement by either glass or graphite fabric or filament. Fabrication of billets involves hot preimpregnation of the reinforcement fabric or filament with polymer followed by wrapping this prepreg over a heated mandrel to form a tube with the required thickness and length.

NASA Lewis' IITA K-12 Program

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA Lewis Research Center's Information Infrastructure Technology and Applications for Kindergarten to 12th Grade (IITA K-12) Program is designed to introduce into school systems computing and communications technology that benefits math and science studies. By incorporating this technology into K-12 curriculums, we hope to increase the proficiency and interest in math and science subjects by K-12 students so that they continue to study technical subjects after their high school careers are over.

Polymer Light-Emitting Diode (PLED) Process Development

DTIC Science & Technology

2003-12-01

conclusions and recommendations for Phase II of the Flexible Display Program. 15. SUBJECT TERMS LIGHT EMITTING DIODES LIQUID CRYSTAL DISPLAY SYSTEMS...space for Phase I and II confined by backplane complexity and substrate form...12 Figure 6. Semi automated I-V curve measurement setup consisting of Keithley power supply, computer and

77 FR 32965 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... importer P-12-0214 03/01/2012 05/01/2012 CBI Laundry and auto Carbohydrate polymers dish wash with acrylic... salt (1:2) initiate. P12-0215 03/01/2012 05/01/2012 CBI Laundry and auto Carbohydrate, polymers dish............ 04/25/2012 04/17/2012 (G) Barium, dialkyl 2-sulfobutanedioate phosphate complexes. P-09-0384...

Polymer concrete reinforced with recycled-tire fibers: Mechanical properties

NASA Astrophysics Data System (ADS)

Martínez-Cruz, E.; Martínez-Barrera, G.; Martínez-López, M.

2013-06-01

Polymer Concrete was reinforced with recycled-tire fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6, 0.9 and 1.2 vol%). The results show increment of 50% in average of the compressive and flexural strength as well as on the deformation when adding 1.2 vol% of recycled-fibers.

Use of Li.sub.2[B.sub.12H.sub.12] salt to absorb water into polymers

DOEpatents

Eastwood, Eric A.; Bowen, III, Daniel E.

2016-08-30

Methods of adjusting the properties of a composition are provided. The compositions comprise a polymer-containing matrix and a filler comprising a hygroscopic salt. Preferred such salts comprise a cage compound selected from the group consisting of borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer.

Sequential Processing for Organic Photovoltaics: Design Rules for Morphology Control by Tailored Semi-Orthogonal Solvent Blends

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

Aguirre, Jordan C.; Hawks, Steven A.; Ferreira, Amy S.

2015-03-18

Design rules are presented for significantly expanding sequential processing (SqP) into previously inaccessible polymer:fullerene systems by tailoring binary solvent blends for fullerene deposition. Starting with a base solvent that has high fullerene solubility, 2-chlorophenol (2-CP), ellipsometry-based swelling experiments are used to investigate different co-solvents for the fullerene-casting solution. By tuning the Flory-Huggins χ parameter of the 2-CP/co-solvent blend, it is possible to optimally swell the polymer of interest for fullerene interdiffusion without dissolution of the polymer underlayer. In this way solar cell power conversion efficiencies are obtained for the PTB7 (poly[(4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)(3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl)]) and PC61BM (phenyl-C61-butyric acid methyl ester) materials combination thatmore » match those of blend-cast films. Both semicrystalline (e.g., P3HT (poly(3-hexylthiophene-2,5-diyl)) and entirely amorphous (e.g., PSDTTT (poly[(4,8-di(2-butyloxy)benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)-alt-(2,5-bis(4,4'-bis(2-octyl)dithieno[3,2-b:2'3'-d]silole-2,6-diyl)thiazolo[5,4-d]thiazole)]) conjugated polymers can be processed into highly efficient photovoltaic devices using the solvent-blend SqP design rules. Grazing-incidence wide-angle x-ray diffraction experiments confirm that proper choice of the fullerene casting co-solvent yields well-ordered interdispersed bulk heterojunction (BHJ) morphologies without the need for subsequent thermal annealing or the use of trace solvent additives (e.g., diiodooctane). The results open SqP to polymer/fullerene systems that are currently incompatible with traditional methods of device fabrication, and make BHJ morphology control a more tractable problem.« less

Evaluation of Eudragit® Retard Polymers for the Microencapsulation of Alpha-Lipoic Acid.

PubMed

Pecora, Tiziana M G; Musumeci, Teresa; Musumeci, Lucrezia; Fresta, Massimo; Pignatello, Rosario

2016-01-01

Microencapsulation of natural antioxidants in polymeric systems represents a possible strategy for improving the oral bioavailability of compounds that are otherwise poorly soluble. α-lipoic acid (ALA) was microencapsulated with polymethacrylate polymers (blends at various ratios of Eudragit® RS100 and RL100 resins). Microspheres were produced by solvent displacement of an ethanol cosolution of ALA and polymers; the microsuspensions were then freeze-dried, using trehalose as a cryoprotector. Microspheres were characterized in the solid state for micromeritic properties and drug loading, as well as by infrared spectroscopy, powder X-ray diffractometry and differential scanning calorimetry. The antioxidant activity of free and encapsulated ALA was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In vitro release studies, performed in simulated gastric (pH 1.2) and intestinal fluid (pH 6.8), showed that, depending on polymer composition and drug-to-polymer ratio, ALA release can be slowed down, compared to the dissolution pattern of the free drug. Solid-state characterization confirmed the chemical stability of ALA in the microspheres, suggesting that ALA did not develop strong interactions with the polymer and was present in an amorphous or a disordered-crystalline state within the polymer network. As indicated by the DPPH assay, the microencapsulation of ALA in Eudragit® Retard matrices did not alter its antioxidant activity. ALA was effectively encapsulated in Eudragit® Retard matrices, showing a chemical stability up to 6 months at room conditions and at 40°C. Moreover, since the drug maintained its antioxidant activity in vitro, the potential application of these microparticulate systems for oral administration would deserve further studies.

Thermosensitive polymer stabilized core-shell AuNR@Ag nanostructures as "smart" recyclable catalyst

NASA Astrophysics Data System (ADS)

Li, Dongxiang; Liu, Na; Gao, Yuanyuan; Lin, Weihong; Li, Chunfang

2017-11-01

Core-shell AuNR@Ag nanostructures were synthesized and surface-grafted with thermosensitive poly( N-isopropylacrylamide) to enhance stability and endow stimuli-responsive property. The AuNR cores showed average dimensions of 8-nm diameter and 33-nm length, while the anisotropic silver shells displayed 1-2 nm thin side and maximal 8 nm fat side. The obtained polymer-stabilized AuNR@Ag nanostructures as catalysts showed normal Arrhenius change of apparent rate constant, k app, in catalyzed reaction between 20 and 30 °C, but displayed a decrease of k app with respect to the temperature increasing between 32.5-40 °C, showing self-inhibition of the observed catalytic activity. Such "smart" self-inhibition of catalytic activity at enhanced temperature can be attributed to the thermosensitive response of the grafted polymer molecules and should be significant to control the reaction rate and avoid superheat for exothermic reactions. Such polymer-stabilized nanocatalyst also could be recovered and reused in the catalytic system. [Figure not available: see fulltext.

Strain-dependent characterization of electrode and polymer network of electrically activated polymer actuators

NASA Astrophysics Data System (ADS)

Töpper, Tino; Osmani, Bekim; Weiss, Florian M.; Winterhalter, Carla; Wohlfender, Fabian; Leung, Vanessa; Müller, Bert

2015-04-01

Fecal incontinence describes the involuntary loss of bowel content and affects about 45 % of retirement home residents and overall more than 12 % of the adult population. Artificial sphincter implants for treating incontinence are currently based on mechanical systems with failure rates resulting in revision after three to five years. To overcome this drawback, artificial muscle sphincters based on bio-mimetic electro-active polymer (EAP) actuators are under development. Such implants require polymer films that are nanometer-thin, allowing actuation below 24 V, and electrodes that are stretchable, remaining conductive at strains of about 10 %. Strain-dependent resistivity measurements reveal an enhanced conductivity of 10 nm compared to 30 nm sputtered Au on silicone for strains higher than 5 %. Thus, strain-dependent morphology characterization with optical microscopy and atomic force microscopy could demonstrate these phenomena. Cantilever bending measurements are utilized to determine elastic/viscoelastic properties of the EAP films as well as their long-term actuation behavior. Controlling these properties enables the adjustment of growth parameters of nanometer-thin EAP actuators.

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

Habercorn, Lasse; Merkl, Jan-Philip; Kloust, Hauke Christian

With the polymer encapsulation of quantum dots via seeded emulsion polymerization we present a powerful tool for the preparation of fluorescent nanoparticles with an extraordinary stability in aqueous solution. The method of the seeded emulsion polymerization allows a straightforward and simple in situ functionalization of the polymer shell under preserving the optical properties of the quantum dots. These requirements are inevitable for the application of semiconductor nanoparticles as markers for biomedical applications. Polymer encapsulated quantum dots have shown only a marginal loss of quantum yields when they were exposed to copper(II)-ions. Under normal conditions the quantum dots were totally quenchedmore » in presence of copper(II)-ions. Furthermore, a broad range of in situ functionalized polymer-coated quantum dots were obtained by addition of functional monomers or surfactants like fluorescent dye molecules, antibodies or specific DNA aptamers. Furthermore the emulsion polymerization can be used to prepare multifunctional hybrid systems, combining different nanoparticles within one construct without any adverse effect of the properties of the starting materials.{sup 1,2}.« less

Competitive sports participation in high school and subsequent substance use in young adulthood: Assessing differences based on level of contact

PubMed Central

Veliz, Philip; Schulenberg, John; Patrick, Megan; Kloska, Deb; McCabe, Sean Esteban; Zarrett, Nicole

2016-01-01

The objective of this analysis is to examine how participation in different types of competitive sports (based on level of contact) during high school is associated with substance use 1 to 4 years after the 12th grade. The analysis uses nationally representative samples of 12th graders from the Monitoring the Future Study who were followed 1 to 4 years after the 12th grade. The longitudinal sample consisted of 970 12th graders from six recent cohorts (2006–2011). The analyses found that respondents who participated in at least one competitive sport during the 12th grade had greater odds of binge drinking during the past two weeks (AOR = 2.04; 95% CI = 1.43, 2.90) 1 to 4 years after the 12th grade, when compared to their peers who did not participate in sports during their 12th grade year. Moreover, respondents who participated in high-contact sports (i.e., football, ice hockey, lacrosse, and wrestling) had greater odds of binge drinking (AOR = 1.80; 95% CI = 1.18, 2.72) and engaging in marijuana use during the past 30 days (AOR = 1.81; 95% CI = 1.12, 2.93) 1 to 4 years after the 12th grade when compared to their peers who did not participate in these types of sports during their 12th grade year. Accordingly, the findings indicate important distinctions in sport participation experiences on long-term substance use risk that can help inform potential interventions among young athletes. PMID:28344426

Youth Risk Behavior Surveillance System: Selected 2011 National Health Risk Behaviors and Health Outcomes by Race/Ethnicity

ERIC Educational Resources Information Center

Centers for Disease Control and Prevention, 2011

2011-01-01

The national Youth Risk Behavior Survey (YRBS) monitors priority health risk behaviors that contribute to the leading causes of death, disability, and social problems among youth and adults in the United States. The national YRBS is conducted every two years during the spring semester and provides data representative of 9th through 12th grade…

Counterbalancing of TH2-driven allergic airway inflammation by IL-12 does not require IL-10.

PubMed

Tournoy, K G; Kips, J C; Pauwels, R A

2001-03-01

Asthma is characterized by allergen-induced airway inflammation orchestrated by TH2 cells. The TH1-promoting cytokine IL-12 is capable of inhibiting the TH2-driven allergen-induced airway changes in mice and is therefore regarded as an interesting strategy for treating asthma. The antiallergic effects of IL-12 are only partially dependent of IFN-gamma. Because IL-12 is a potent inducer of the anti-inflammatory cytokine IL-10, the aim of the present study was to investigate in vivo whether the antiallergic effects of IL-12 are mediated through IL-10. C57BL/6J-IL-10 knock-out (IL-10(-/-)) mice were sensitized intraperitoneally to ovalbumin (OVA) and subsequently exposed from day 14 to day 21 to aerosolized OVA (1%). IL-12 was administered intraperitoneally during sensitization, subsequent OVA exposure, or both. IL-12 inhibited the OVA-induced airway eosinophilia, despite the absence of IL-10. Moreover, a shift from a TH2 inflammatory pattern toward a TH1 reaction was observed, with concomitant pronounced mononuclear peribronchial inflammation after IL-12 treatment. Allergen-specific IgE synthesis was completely suppressed only when IL-12 was administered along with the allergen sensitization. Furthermore, treating the animals with IL-12 at the time of the secondary allergen challenge resulted not only in a significant suppression of the airway responsiveness but also in an important IFN-gamma-associated toxicity. These results indicate that IL-12 is able to inhibit allergen-induced airway changes, even in the absence of IL-10. In addition, our results raise concerns regarding the redirection of TH2 inflammation by TH1-inducing therapies because treatment with IL-12 resulted not only in a disappearance of the TH2 inflammation but also in a TH1-driven inflammatory pulmonary pathology.

Evaluating Earth and Space Sciences STEM Research Communication in 7th-12th Grade Rural Mississippi Classrooms and Resulting Student Attitudinal Impacts

NASA Astrophysics Data System (ADS)

Radencic, S.; McNeal, K. S.

2013-05-01

Observation and evaluation of STEM graduate students from Mississippi State University communicating their research of the Earth and Space Sciences in rural 7th-12th grade classrooms participating in the Initiating New Science Partnerships in Rural Education (INSPIRE) NSF GK-12 project. The methods they utilize to communicate their STEM research includes introducing new technologies and inquiry based learning experiences. These communication experiences have been observed and evaluated using two observational systems, the Mathematics Science Classroom Observational Profile System (M-SCOPS) and the Presentation Skills Protocol (PSP). M-SCOPS has been used over the first three years of the project to evaluate what Earth and Space research the STEM graduate students communicate in classroom activities along with how they are introducing STEM research through a variety of communication methods and levels of understanding. PSP, which INSPIRE began using this year, evaluates and provides feedback to the STEM graduate students on their communication during these classroom experiences using a rubric covering a range of skills for successful communication. PSP also allows the participating INSPIRE teacher partners to provide feedback to the STEM graduate students about development of their communication skills over the course of the year. In addition to feedback from the INSPIRE project and participating teachers, the STEM graduate students have the opportunity to evaluate their personal communication skills through video documentation to determine specific skills they would like to improve. Another area of research to be discussed is how the STEM graduate students communicating Earth and Space sciences research in the participating classrooms is impacting student attitudes about science and mathematics over the last three years. Student Attitudinal Surveys (SAS) are administered as a pre-evaluation tool in the fall when the STEM graduate students first enter into their partner classrooms and again each spring for post-evaluation before the STEM graduate students depart from the classrooms. An evaluation of graduate communication effectiveness will be related to the 7th-12th grade student attitudes about science and mathematics.

Chemical and structural evolution in the Th-SeO3(2-)/SeO4(2-) system: from simple selenites to cluster-based selenate compounds.

PubMed

Xiao, Bin; Langer, Eike; Dellen, Jakob; Schlenz, Hartmut; Bosbach, Dirk; Suleimanov, Evgeny V; Alekseev, Evgeny V

2015-03-16

While extensive success has been gained in the structural chemistry of the U-Se system, the synthesis and characterization of Th-based Se structures are widely unexplored. Here, four new Th-Se compounds, α-Th(SeO3)2, β-Th(SeO3)2, Th(Se2O5)2, and Th3O2(OH)2(SeO4)3, have been obtained from mild hydrothermal or low-temperature (180-220 °C) flux conditions and were subsequently structurally and spectroscopically characterized. The crystal structures of α-Th(SeO3)2 and β-Th(SeO3)2 are based on ThO8 and SeO3 polyhedra, respectively, featuring a three-dimensional (3D) network with selenite anions filling in the Th channels along the a axis. Th(Se2O5)2 is a 3D framework composed of isolated ThO8 polyhedra interconnected by [Se2O5](2-) dimers. Th3O2(OH)2(SeO4)3 is also a 3D framework constructed by octahedral hexathorium clusters [Th6(μ3-O)4(μ3-OH)4](12+), which are interlinked by selenate groups SeO4(2-). The positions of the vibrational modes associated with both Se(IV)O3(2-) and Se(VI)O4(2-) units, respectively, were determined for four compounds, and the Raman spectra of α- and β-Th(SeO3)2 are compared and discussed in detail.

Osmotic pellet system comprising osmotic core and in-process amorphized drug in polymer-surfactant layer for controlled delivery of poorly water-soluble drug.

PubMed

Saindane, Nilesh; Vavia, Pradeep

2012-09-01

The aim of the present investigation was to develop controlled porosity osmotic system for poorly water-soluble drug based on drug in polymer-surfactant layer technology. A poorly water-soluble drug, glipizide (GZ), was selected as the model drug. The technology involved core of the pellets containing osmotic agent coated with drug dispersed in polymer and surfactant layer, finally coated with release-retardant layer with pore former. The optimized drug-layer-coated pellets were evaluated for solubility of GZ at different pH conditions and characterized for amorphous nature of the drug by differential scanning calorimetry and X-ray powder diffractometry. The optimized release-retardant layer pellets were evaluated for in vitro drug release at different pH, hydrodynamic, and osmolality conditions. The optimized drug layer showed improvement in solubility (10 times in pH 1.2, 11 times in pH 4.5, and 21 times in pH 6.8), whereas pellets coated with cellulose acetate (15.0%, w/w, weight gain) with pore former triethyl citrate (10.0%, w/w, of polymer) demonstrated zero-order drug release for 24 h at different pH conditions; moreover, retardation of drug release was observed with increment of osmolality. This system could be a platform technology for controlled delivery of poorly water-soluble drugs. Copyright © 2012 Wiley Periodicals, Inc.

Hollow microspheres of diclofenac sodium - a gastroretentive controlled delivery system.

PubMed

Bv, Basavaraj; R, Deveswaran; S, Bharath; Abraham, Sindhu; Furtado, Sharon; V, Madhavan

2008-10-01

Most of the floating systems have an inherent drawback of high variability in the GI transit time, invariably affecting the bioavailability of drug. To overcome it, a multiple unit floating system with extended GI transit time, capable of distributing widely throughout the GIT for effective enteric release of the drug has been sought. Microballoons loaded with drug in their outer polymer shells were prepared by novel emulsion solvent diffusion method. The ethanol: dicloromethane solution of drug and Eudragit-S were poured into an aqueous solution of PVA that was thermally controlled at 40 degrees C. The gas phase generated in the dispersed polymer droplet by the evaporation of solvent formed an internal cavity in the microsphere of the polymer with the drug. The flowability of the resulting microballoons improved when compared to pure drug. The microballoons on floatation along with the surfactant, floated continuously for more than 12 hours in the acidic medium in-vitro conditions. The in-vitro drug release profile of the formulation in the simulated gastric buffer showed no drug release, which emphasizes the enteric release property and in simulated intestinal buffer, a slow and controlled drug release of 60 to 84% was obtained over a period of 8 hours. Drug release was significantly affected by increased drug to polymer concentration at pH 6.8. The formulation was found to be physically and chemically stable as per the ICH guidelines.

12th Anglo-French Physical Acoustics Conference (AFPAC2013)

NASA Astrophysics Data System (ADS)

2014-04-01

The Anglo-French Physical Acoustics Conference (AFPAC) had its 12th annual meeting in Villa Clythia, Fréjus, France, from 16th to 18th January 2013. This series of meetings is a collaboration between the Physical Acoustics Group (PAG) of the Institute of Physics and the Groupe d'Acoustique Physique, Sous-marine et UltraSonore (GAPSUS) of the Société Française d'Acoustique. This year, attendees got the opportunity to see the French Riviera with its Mediterranean vegetation covered by a nice thick snow layer. The participants heard 34 excellent oral presentations and saw 3 posters covering an exciting and diverse range of subjects and of frequencies, from ultrasonic wave propagation in chocolate to metamaterials applied to seismic waves for protecting buildings. Among them, invited talks were given by Pr F A Duck ( Enhanced healing by ultrasound: clinical effects and mechanisms), Pr. J-C Valiére, who actually gave two invited talks ( 1. Measurement of audible acoustic particle velocity using laser: Principles, signal processing and applications, 2. Acoustic pots in ancient and medieval buildings: Literary analysis of ancient texts and comparison with recent observations in French churches), Dr P Huthwaite ( Ultrasonic imaging through the resolution of inverse problems), Dr X Lurton ( Underwater acoustic systems on oceanographic research vessels: principles and applications), Dr S Guenneau ( From platonics to seismic metamaterials). For the fifth consecutive year AFPAC is followed by the publication of its proceedings with 12 peer-reviewed papers which cover the most recent research developments in the field of Physical Acoustics in the UK and France. Alain Lhémery (CEA, France) and Nader Saffari (UCL, United Kingdom) French Riviera 12th AFPAC — Villa Clythia, Fréjus (French Riviera), the 17th of January 2013

12 CFR 261.11 - Records available for public inspection and copying.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Governors of the Federal Reserve System, 20th Street and Constitution Avenue, N.W., Washington, D.C. 20551... copying. 261.11 Section 261.11 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM (CONTINUED) RULES REGARDING AVAILABILITY OF INFORMATION Published...

Space environmental effects on polymeric materials

NASA Technical Reports Server (NTRS)

Kiefer, Richard L.; Orwoll, Robert A.

1988-01-01

Two of the major environmental hazards in the Geosynchronous Earth Orbit (GEO) are energetic charged particles and ultraviolet radiation. The charged particles, electrons and protons, range in energy from 0.1 to 4 MeV and each have a flux of 10 to the 8th sq cm/sec. Over a 30 year lifetime, materials in the GEO will have an absorbed dose from this radiation of 10 to the 10th rads. The ultraviolet radiation comes uninhibited from the sun with an irradiance of 1.4 kw/sq m. Radiation is known to initiate chain sission and crosslinking in polymeric materials, both of which affect their structural properties. The 30-year dose level from the combined radiation in the GEO exceeds the threshold for measurable damage in most polymer systems studied. Of further concern is possible synergistic effects from the simultaneous irradiation with charged particles and ultraviolet radiation. Most studies on radiation effects on polymeric materials use either electrons or ultraviolet radiation alone, or in a sequential combination.

Development of space stable semitransparent polyquinoxaline films

NASA Technical Reports Server (NTRS)

Hergenrother, P. M.

1972-01-01

Three polyphenylquinoxalines underwent preliminary study for potential use as coatings on aircraft and spacecraft. These polymers were prepared from the reaction of 3,3 prime, 4,4 prime-tetraaminodiphenyl ether with p,p prime-oxydibenzil and with m -bis (phenylglyoxalyl) benzene and from the reaction of 3,3 prime, 4,4 prime-tetraaminodiphenylsulfone with p,p prime-oxydibenzil. High purity reactants and solvents were used in polymer preparation to minimize color in the polymer films. High molecular weight polymers were prepared at ambient temperature at 12 to 15 percent concentration by upsetting the stoichiometry by 0.5 to 1.0 percent in favor of the bis (1,2-dicarbonyl) reactant. A portion of each polymer was endcapped with benzil and with o-phenylenediamine. Certain properties of the endcapped and unendcapped versions of each polymer are compared. Uniform films of 2.0 and 0.1 mil thickness were cast from solutions of the unendcapped and endcapped versions of each of the three polymers.

Youth problem behaviors 8 years after implementing the communities that care prevention system: a community-randomized trial.

PubMed

Hawkins, J David; Oesterle, Sabrina; Brown, Eric C; Abbott, Robert D; Catalano, Richard F

2014-02-01

Community-based efforts to prevent adolescent problem behaviors are essential to promote public health and achieve collective impact community wide. OBJECTIVE To test whether the Communities That Care (CTC) prevention system reduced levels of risk and adolescent problem behaviors community wide 8 years after implementation of CTC. A community-randomized trial was performed in 24 small towns in 7 states, matched within state, assigned randomly to a control or intervention group in 2003. All fifth-grade students attending public schools in study communities in 2003-2004 who received consent from their parents to participate (76.4% of the eligible population) were included. A panel of 4407 fifth graders was surveyed through 12th grade, with 92.5% of the sample participating at the last follow-up. A coalition of community stakeholders received training and technical assistance to install CTC, used epidemiologic data to identify elevated risk factors and depressed protective factors for adolescent problem behaviors in the community, and implemented tested and effective programs for youths aged 10 to 14 years as well as their families and schools to address their community's elevated risks. MAIN OUTCOMES AND MEASURES Levels of targeted risk; sustained abstinence, and cumulative incidence by grade 12; and current prevalence of tobacco, alcohol, and other drug use, delinquency, and violence in 12th grade. By spring of 12th grade, students in CTC communities were more likely than students in control communities to have abstained from any drug use (adjusted risk ratio [ARR] = 1.32; 95% CI, 1.06-1.63), drinking alcohol (ARR = 1.31; 95% CI, 1.09-1.58), smoking cigarettes (ARR = 1.13; 95% CI, 1.01-1.27), and engaging in delinquency (ARR = 1.18; 95% CI, 1.03-1.36). They were also less likely to ever have committed a violent act (ARR = 0.86; 95% CI, 0.76-0.98). There were no significant differences by intervention group in targeted risks, the prevalence of past-month or past-year substance use, or past-year delinquency or violence. Using the CTC system continued to prevent the initiation of adolescent problem behaviors through 12th grade, 8 years after implementation of CTC and 3 years after study-provided resources ended, but did not produce reductions in current levels of risk or current prevalence of problem behavior in 12th grade. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01088542.

SU-G-IeP4-07: Feasibility of Low Dose 18FDG PET in Pediatric Oncology Patients

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

Zhang, J; Binzel, K; Hall, NC

Purpose: To evaluate and demonstrate the feasibility of low dose FDG PET in pediatric oncology patients using virtual dose reduction as well as true patients PET/CT scans. Methods: Wholebody 18F-FDG PET/CT of 39 clinical pediatric patients (0.16±0.06MBq/kg) were scanned on a Gemini TF 64 system at 75±5 min post FDG injection using 3min/bed. Based on the 180s/bed listmode PET data, subsets of total counts in 120s, 90s, 60s, 30s and 15s per bed position were extracted for PET reconstruction to simulate lower dose PET at 2/3th, 1/2th, 1/3th, 1/6th and 1/12th dose levels. PET/CT scans of Jaszczak PET phantom withmore » 6 hot hollow spheres varying with sizes and contrast ratios were performed (real PET versus simulated PET) to validate the methodology of virtual dose PET simulation. Region of interests (ROIs) were placed on lesions and normal anatomical tissues with quantitative and qualitative assessment performed. Significant lower FDG dose PET/CT of 5 research adolescents were scanned to validate the proposal and low dose PET feasibility. Results: Although all lesions are visible on the 1/12th dose PET, overall PET image quality appears to be influenced in a multi-factorial way. 30%–60% dose reduction from current standard of care FDG PET is recommended to maintain equivalent quality and PET quantification. An optimized BMI-based FDG administration is recommended (from 1.1±0.5 mCi for BMI < 18.5 to 4.8±1.5 mCi for BMI > 30). A linear lowest “Dose-BMI” relationship is given. SUVs from 1/12th to full dose PETs were identified as consistent (R2 = 1.08, 0.99, 1.01, 1.00 and 0.98). No significant variances of count density, SUV and SNR were found across certain dose ranges (p<0.01). Conclusion: Pediatric PET/CT can be performed using current time-of-flight systems at substantially lower PET doses (30–60%) than the standard of care PET/CT without compromising qualitative and quantitative image quality in clinical.« less

Distinct pathways of humoral and cellular immunity induced with the mucosal administration of a nanoemulsion adjuvant.

PubMed

Bielinska, Anna U; Makidon, Paul E; Janczak, Katarzyna W; Blanco, Luz P; Swanson, Benjamin; Smith, Douglas M; Pham, Tiffany; Szabo, Zsuzsanna; Kukowska-Latallo, Jolanta F; Baker, James R

2014-03-15

Nasal administration of an oil-in-water nanoemulsion (NE) adjuvant W805EC produces potent systemic and mucosal, Th-1- and Th-17-balanced cellular responses. However, its molecular mechanism of action has not been fully characterized and is of particular interest because NE does not contain specific ligands for innate immune receptors. In these studies, we demonstrate that W805EC NE adjuvant activates innate immunity, induces specific gene transcription, and modulates NF-κB activity via TLR2 and TLR4 by a mechanism that appears to be distinct from typical TLR agonists. Nasal immunization with NE-based vaccine showed that the TLR2, TLR4, and MyD88 pathways and IL-12 and IL-12Rβ1 expression are not required for an Ab response, but they are essential for the induction of balanced Th-1 polarization and Th-17 cellular immunity. NE adjuvant induces MHC class II, CD80, and CD86 costimulatory molecule expression and dendritic cell maturation. Further, upon immunization with NE, adjuvant mice deficient in the CD86 receptor had normal Ab responses but significantly reduced Th-1 cellular responses, whereas animals deficient in both CD80 and CD86 or lacking CD40 failed to produce either humoral or cellular immunity. Overall, our data show that intranasal administration of Ag with NE induces TLR2 and TLR4 activation along with a MyD88-independent Ab response and a MyD88-dependent Th-1 and Th-17 cell-mediated immune response. These findings suggest that the unique properties of NE adjuvant may offer novel opportunities for understanding previously unrecognized mechanisms of immune activation important for generating effective mucosal and systemic immune responses.

Ternary Polymer Solar Cells based on Two Acceptors and One Donor for Achieving 12.2% Efficiency.

PubMed

Zhao, Wenchao; Li, Sunsun; Zhang, Shaoqing; Liu, Xiaoyu; Hou, Jianhui

2017-01-01

Ternary polymer solar cells are fabricated based on one donor PBDB-T and two acceptors (a methyl-modified small-molecular acceptor (IT-M) and a bis-adduct of Bis[70]PCBM). A high power conversion efficiency of 12.2% can be achieved. The photovoltaic performance of the ternary polymer solar cells is not sensitive to the composition of the blend. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Education and prevention for teens: using Trauma Nurses Talk Tough presentation with pretest and posttest evaluation of knowledge and behavior changes.

PubMed

Allabaugh, Chianti Terri; Maltz, Sheldon; Carlson, Glenn; Watcharotone, Kuanwong

2008-01-01

Injury prevention is an essential part of any trauma program. Trauma Nurses Talk Tough (TNTT) is an injury prevention program utilized at many trauma centers targeting school-aged children from kindergarten through 12th grade. We hypothesized that TNTT would increase knowledge of safety strategies and change behavior with a prospective, correlational study using TNTT for 6th- to 8th-grade (n = 372) and 9th- to 12th-grade (n = 158) students, respectively. The TNTT injury prevention program had an effect on all students of 6th to 12th grades; however, the effect was more pronounced in the 6th- to 8th-grade group.

Donor/Acceptor Molecular Orientation-Dependent Photovoltaic Performance in All-Polymer Solar Cells.

PubMed

Zhou, Ke; Zhang, Rui; Liu, Jiangang; Li, Mingguang; Yu, Xinhong; Xing, Rubo; Han, Yanchun

2015-11-18

The correlated donor/acceptor (D/A) molecular orientation plays a crucial role in solution-processed all-polymer solar cells in term of photovoltaic performance. For the conjugated polymers PTB7-th and P(NDI2OD-T2), the preferential molecular orientation of neat PTB7-th films kept face-on regardless of the properties of processing solvents. However, an increasing content of face-on molecular orientation in the neat P(NDI2OD-T2) films could be found by changing processing solvents from chloronaphthalene (CN) and o-dichlorobenzene (oDCB) to chlorobenzene (CB). Besides, the neat P(NDI2OD-T2) films also exhibited a transformation of preferential molecular orientation from face-on to edge-on when extending film drying time by casting in the same solution. Consequently, a distribution diagram of molecular orientation for P(NDI2OD-T2) films was depicted and the same trend could be observed for the PTB7-th/P(NDI2OD-T2) blend films. By manufacture of photovoltaic devices with blend films, the relationship between the correlated D/A molecular orientation and device performance was established. The short-circuit current (Jsc) of devices processed by CN, oDCB, and CB enhanced gradually from 1.24 to 8.86 mA/cm(2) with the correlated D/A molecular orientation changing from face-on/edge-on to face-on/face-on, which could be attributed to facile exciton dissociation at D/A interface with the same molecular orientation. Therefore, the power conversion efficiency (PCE) of devices processed by CN, oDCB, and CB improved from 0.53% to 3.52% ultimately.

STILT: System design and performance

NASA Astrophysics Data System (ADS)

Mawson, N. R.; Steele, I. A.; Smith, R. J.

2013-08-01

The Small Telescopes Installed at the Liverpool Telescope (STILT) have been in operation since March 2009, collecting wide field data from their position, mounted to the Liverpool Telescope. The two instruments; SkycamT and SkycamZ have been used to create a variability search of the skies visible at La Palma with the limits of 12th and 18th R-band magnitude with fields of view of 21°× 21o and 1°× 1o. We provide here a description of the hardware and software setup and the performance of the system to date.

Design of ultra-broadband terahertz polymer waveguide emitters for telecom wavelengths using coupled mode theory.

PubMed

Vallejo, Felipe A; Hayden, L Michael

2013-03-11

We use coupled mode theory, adequately incorporating optical losses, to model ultra-broadband terahertz (THz) waveguide emitters (0.1-20 THz) based on difference frequency generation of femtosecond infrared (IR) optical pulses. We apply the model to a generic, symmetric, five-layer, metal/cladding/core waveguide structure using transfer matrix theory. We provide a design strategy for an efficient ultra-broadband THz emitter and apply it to polymer waveguides with a nonlinear core composed of a poled guest-host electro-optic polymer composite and pumped by a pulsed fiber laser system operating at 1567 nm. The predicted bandwidths are greater than 15 THz and we find a high conversion efficiency of 1.2 × 10(-4) W(-1) by balancing both the modal phase-matching and effective mode attenuation.

Tuning the electronic and optical properties of NDT-based conjugated polymers by adopting fused heterocycles as acceptor units: a theoretical study.

PubMed

Cheng, Na; Zhang, Changqiao; Liu, Yongjun

2017-08-01

Donor-acceptor conjugated polymers have been successfully applied in bulk heterojunction solar cell devices. Tuning their donor and acceptor units allows the design of new polymers with desired electronic and optical properties. Here, to screen new candidate polymers based on a newly synthesized donor unit, dithieo[2,3-d:2',3'-d']naphtho[1,2-b:3,4-b']dithiophene (NDT), a series of model polymers with different acceptor units were designed and denoted NDT-A 0 to NDT-A 12 , and the structures and optical properties of those polymers were investigated using DFT and TDDFT calculations. The results of the calculations revealed that the electronic and optical properties of these polymers depend on the acceptor unit present; specifically, their HOMO energies ranged from -4.89 to -5.38 eV, their HOMO-LUMO gaps ranged from 1.30 to 2.80 eV, and their wavelengths of maximum absorption ranged from 538 to 1212 nm. The absorption spectra of NDT-A 1 to NDT-A 6 , NDT-A 8 , NDT-A 9 , and NDT-A 12 occur within the visible region (<900 nm), indicating that these polymers are potential candidates for use in solar cells. On the other hand, the absorption spectra of NDT-A 7 , NDT-A 10 , and NDT-A 11 extend much further into the near-infrared region, implying that they absorb near-infrared light. These polymers could meet the requirements of donor units for use in tandem and ternary solar cells. Graphical abstract Theoretical calculations by TD-DFT reveal that the optical properties of NDT-based conjugated polymers can be well tuned by adopting different acceptor units, and these ploymers are potential donor materials for tandem and ternary solar cells.

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

Fate vs choice: the immune system reloaded.

PubMed

Murphy, Kenneth M

2005-01-01

Development can occur by either instructive or stochastic processes. My colleagues and I have studied the contributions of these processes to differentiation of naïve CD4+ T-cells to either a Th1 or Th2 phenotype. Our initial discovery that pathogens in our in vitro priming system led to the development of Th1 cells through the action of interleukin-12 was important evidence of a link between innate and adaptive immunity. Subsequent studies in our laboratory revealed an important role for GATA-3 autoactivation in Th2 development. Other interesting projects that have emerged as a result of our Th cell differentiation studies include understanding the role of the inhibitory immunoreceptor B- and T-lymphocyte attenuator in the immune response, as well as the role of the transcription factor ERM in both T-cells and spermatogenesis. We currently maintain our interests in the Th differentiation field by trying to understand the role of type 1 interferons in Th1 development and the role of alternate promoters for the GATA-3 gene, among other things, but are also actively embarking on studies related to the choice between divergent cell types during embryonic stem cell differentiation.

Insights into the Morphological Instability of Bulk Heterojunction PTB7-Th/PCBM Solar Cells upon High-Temperature Aging

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

Hsieh, Yen-Ju; Huang, Yu-Ching; Liu, Wei-Shin

The impact of the morphological stability of the donor/acceptor mixture under thermal stress on the photovoltaic properties of bulk heterojunction (BHJ) solar cells based on the poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']-di-thiophene-2,6-diyl-alt-(4-(2 ethylhexyl)-3-fluorothieno[3,4-b]-thiophene)-2-carboxylate-2,6-diyl]/phenyl-C61-butyric acid methylester (PTB7-Th/PC61BM) blend is extensively investigated. Both optical microscopy and transmission electron microscopy micrographs show that long-term high-temperature aging stimulates the formation of microscale clusters, the size of which, however, is about 1 order of magnitude smaller than those observed in thermally annealed poly(3hexylthiophene)/PC61BM composite film. The multilength-scale evolution of the morphology of PTB7-Th/PC61BM film from the scattering profiles of grazing incidence small-angle and wide-angle X-ray scattering indicates the PC61BM moleculesmore » spatially confine the self-organization of polymer chains into large domains during cast drying and upon thermal activation. Moreover, some PC61BM molecules accumulate into ~30-40 nm clusters, the number of which increases with heating time. Therefore, the hole mobility in the active layer decays much more rapidly than the electron mobility, leading to unbalanced charge transport and degraded cell performance. Importantly, the three-component blend that is formed by replacing a small amount of PC61BM in the active layer with the bis-adduct of PC61BM (bis-P61M) exhibits robust morphology against thermal stress. Accordingly, the PTB7-Th/PC61BM:bis-PC61BM (8 wt %) device has an extremely stable power conversion efficiency.« less

Three-Dimensional-Moldable Nanofiber-Reinforced Transparent Composites with a Hierarchically Self-Assembled "Reverse" Nacre-like Architecture.

PubMed

Biswas, Subir K; Sano, Hironari; Shams, Md Iftekhar; Yano, Hiroyuki

2017-09-06

Achieving a structural hierarchy and a uniform nanofiller dispersion simultaneously remains highly challenging for obtaining a robust polymer nanocomposite of immiscible components. In this study, a remarkably facile Pickering emulsification approach is developed to fabricate hierarchical composites of immiscible acrylic polymer and native cellulose nanofibers by taking advantage of the dual role of the nanofibers as both emulsion stabilizer and polymer reinforcement. The composites feature a unique "reverse" nacre-like microstructure reinforced with a well-dispersed two-tier hierarchical nanofiber network, leading to a synergistic high strength, modulus, and toughness (20, 50, and 53 times that of neat polymer, respectively), high optical transparency (89%), high flexibility, and a drastically low thermal expansion (13 ppm K -1 , 1/15th of the neat polymer). The nanocomposites have a three-dimensional-shape moldability, also their surface can be patterned with micro/nanoscale features with high fidelity by in situ compression molding, making them attractive as the substrate for flexible displays, smart contact lens devices, and photovoltaics. The Pickering emulsification approach should be broadly applicable for the fabrication of novel functional materials of various immiscible components.

Surface properties of functional polymer systems

NASA Astrophysics Data System (ADS)

Wong, Derek

Polymer surface modification typically involves blending with other polymers or chemical modification of the parent polymer. Such strategies inevitably result in polymer systems that are spatially and chemically heterogeneous, and which exhibit the phenomenon of surface segregation. This work investigates the effects of chain architecture on the surface segregation behavior of such functionally modified polymers using a series of end- and center-fluorinated poly(D,L-lactide). Surface segregation of the fluorinated functional groups was observed in both chain architectures via AMPS and water contact angle. Higher surface segregation was noted for functional groups located at the chain end as opposed to those in the middle of the chain. A self-consistent mean-field lattice theory was used to model the composition depth profiles of functional groups and excellent agreement was found between the model predictions and the experimental AMPS data in both chain architectures. Polymer properties are also in general dependent on both time and temperature, and exhibit a range of relaxation times in response to environmental stimuli. This behavior arises from the characteristic frequencies of molecular motions of the polymer chain and the interrelationship between time and temperature has been widely established for polymer bulk properties. There is evidence that surface properties also respond in a manner that is time and temperature dependent and that this dependence may not be the same as that observed for bulk properties. AMPS and water contact angle experiments were used to investigate the surface reorganization behavior of functional groups using a series of anionically synthesized end-fluorinated and end-carboxylated poly(styrene). It was found that both types of functional end-groups reorganized upon a change in the polarity of the surface environment in order to minimize the surface free energy. ADXPS and contact angle results suggest that the reorganization depth was confined to the top 2--3 nm of the surface. Contact angle results showed also that the reorganization process proceeded as a function of (time) 1/2, indicating that it is likely diffusion controlled. The magnitudes of the activation energies determined from the experimental data according to the Arhenius equation, suggest that the process is possibly correlated with known bulk beta and gamma relaxations in the polymer.

Symposium on the Chemistry and Toxicology of Acrylamide

USDA-ARS?s Scientific Manuscript database

Acrylamide is used worldwide to synthesize polyacrylamide. The polymer has found many applications as a soil conditioner, in wastewater treatment, in the cosmetic, paper, and textile industries, and in the laboratory as a solid support for the separation of proteins by electrophoresis. Because of th...

Fluorescent quantum dot hydrophilization with PAMAM dendrimer

NASA Astrophysics Data System (ADS)

Potapkin, Dmitry V.; Geißler, Daniel; Resch-Genger, Ute; Goryacheva, Irina Yu.

2016-05-01

Polyamidoamine (PAMAM) dendrimers were used to produce CdSe core/multi-shell fluorescent quantum dots (QDs) which are colloidally stable in aqueous solutions. The size, charge, and optical properties of QDs functionalized with the 4th (G4) and 5th (G5) generation of PAMAM were compared with amphiphilic polymer-covered QDs and used as criteria for the evaluation of the suitability of both water solubilization methods. As revealed by dynamic and electrophoretic light scattering (DLS and ELS), the hydrodynamic sizes of the QDs varied from 30 to 65 nm depending on QD type and dendrimer generation, with all QDs displaying highly positive surface charges, i.e., zeta potentials of around +50 mV in water. PAMAM functionalization yielded stable core/multi-shell QDs with photoluminescence quantum yields ( Φ) of up to 45 %. These dendrimer-covered QDs showed a smaller decrease in their Φ upon phase transfer compared with QDs made water soluble via encapsulation with amphiphilic brush polymer bearing polyoxyethylene/polyoxypropylene chains.

Effects of asarinin on dopamine biosynthesis and 6-hydroxydopamine-induced cytotoxicity in PC12 cells.

PubMed

Park, Hyun Jin; Lee, Kyung Sook; Zhao, Ting Ting; Lee, Kyung Eun; Lee, Myung Koo

2017-05-01

This study investigated the effects of asarinin on dopamine biosynthesis and 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in rat adrenal pheochromocytoma (PC12) cells. Treatment with asarinin (25-50 μM) increased intracellular dopamine levels and enhanced L-DOPA-induced increases in dopamine levels. Asarinin (25 μM) induced cyclic AMP-dependent protein kinase A (PKA) signaling, leading to increased cyclic AMP-response element binding protein (CREB) and tyrosine hydroxylase (TH) phosphorylation, which in turn stimulated dopamine production. Asarinin (25 μM) also activated transient phosphorylation of extracellular signal-regulated kinase (ERK1/2) and Bad phosphorylation at Ser 112, both of which have been shown to promote cell survival. In contrast, asarinin (25 μM) inhibited sustained ERK1/2, Bax, c-Jun N-terminal kinase (JNK1/2) and p38 mitogen-activated protein kinase (p38MAPK) phosphorylation and caspase-3 activity, which were induced by 6-OHDA (100 μM). These results suggest that asarinin induces dopamine biosynthesis via activation of the PKA-CREB-TH system and protects against 6-OHDA-induced cytotoxicity by inhibiting the sustained activation of the ERK-p38MAPK-JNK1/2-caspase-3 system in PC12 cells.

Can Students Collaboratively Use Hypermedia to Learn Science? The Dynamics of Self-And Other-Regulatory Processes in an Ecology Classroom

ERIC Educational Resources Information Center

Azevedo, Roger; Winters, Fielding I.; Moos, Daniel C.

2004-01-01

This classroom study examined the role of low-achieving students' self-regulated learning (SRL) behaviors and their teacher's scaffolding of SRL while using a Web-based water quality simulation environment to learn about ecological systems. Forty-nine 11th and 12th grade students learned about ecology and the effects of land use on water quality…

11th Annual Small Business Conference :Army and Small Business: Success Thru Partnership

DTIC Science & Technology

2007-11-08

Management Commands… Soldier Focused As of 12 Sep 07 Technology /System Improvements Army Sustainment Command: AMC’s Face to the Field Improvement Suggestions...Acquisition, Logistics and Technology ) “Update on the State of the Army Small Business Program”, Ms. Tracey L. Pinson, Director, Small and...Partner”, Ms. January Dennison, President, Technology Research Consultants, Inc.  11th Annual Small Business Conference Objective & Scope

Synthesis and characterization of polyaniline coated gold nanocomposites

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

Zuber, Siti Nurzulaiha Mohd; Kamarun, Dzaraini; Zaki, Hamizah

2015-08-28

Considerable attention has been drawn during the last two decades to prepare nanocomposites consists of conducting polymer and noble metal due to their potential ability to generate a new class of material with novel optical, chemical, electronic or mechanical properties for various applications. In this work, an attempt has been made to synthesize nanocomposite of polyaniline (PANI) coated with gold nanoparticles (AuNPs) chemically with various types of surfactants such as polyvinylpyrrolidone (PVP), and sodium dodecyl sulphate (SDS) which act as stabilizing agents to help in stabilization of the PANI/Gold nanocomposites system. The synthesized nanocomposites were characterized by UV-Visible, field emissionmore » scanning electron microscope (FESEM) and particle size analyzer (PSA). The formation of finger like structure can be seen in the FESEM images when the AuNPs were incorporated into the polymer matrix. The EDX data showed that 18.66% and 12.67% of AuNPs atoms were present in the composite system thus proved the incorporation of AuNPs into the polymer matrix. A small red shift of the absorption peak in the UV-Vis of both PANI/AuNPs composites system may be due to the incorporation of AuNPs in the PANI matrix.« less

Co-encapsulation of curcumin and resveratrol into novel nutraceutical hyalurosomes nano-food delivery system based on oligo-hyaluronic acid-curcumin polymer.

PubMed

Guo, Chunjing; Yin, Jungang; Chen, Daquan

2018-02-01

In this work, in order to enhance the stability, bioavailability and antioxidant activity of insoluble antioxidants used into juice, yoghourt and nutritional supplements, the oligo-hyalurosomes nano-delivery system (CRHs) based on oligo-hyaluronic acid -curcumin (oHC) polymer loaded curcumin(Cur) and resveratrol (Res) was fabricated with new nanotechnolgy. The rosy biodegradable amphiphilic oHC polymer was successfully synthesized and used to fabricate the hyalurosomes containing both Cur and Res, called CRHs. The CRHs can spontaneously self-assemble into nano-sized spherical shape of average particle size 134.5±5.1nm and Zeta potential -29.4±1.2 at pH 7.4 PBS conditions. In vitro gastrointestinal release test showed a perfect stability and outstanding sustained release character. Moreover, compared to the single formulations and liposomes, CRHs showed a dose-dependent manner with a higher radical scavenging activity. Therefore, the novel CRHs nano-food manifested the hopeful properties for the new effective gastrointestinal formulation and promising new nano-food delivery system in the use of juice, yoghourt and nutritional supplements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Composite seals for liquid hydrogen and nuclear radiation environments.

NASA Technical Reports Server (NTRS)

Van Auken, R. L.; Chase, V. A.

1971-01-01

Description of plastic composite seals for service in a liquid-hydrogen and nuclear-radiation environment. The radiation-resistant aromatic heterocyclic class of polymers, including polyimide, polybenzimidazole, and polyquinoxaline, were evaluated for this application. The seal developed is based on a design involving a resin-starved laminate consisting of alternating layers of woven glass fabric and polymer film. This design imparts a mechanical spring characteristic to the seal, resulting in essentially complete elastic recovery when unloaded, and eliminates cold flow. Encapsulating techniques employing the polyquinoxaline polymer were developed which rendered the seal impervious to liquid hydrogen. The seals were tested before and after gamma irradiation up to 10 to the 10th ergs/g. Load/deflection and leakage tests were performed over a temperature range from -423 through +500 F.

Announcements | High-Performance Computing | NREL

Science.gov Websites

12th from 12 - 3 PM. Continue reading Data Transfer Queue March 08, 2018 A new queue "data , scratch) and MSS. Continue reading Purge-Alert January 11, 2018 We now have a notification method that . Continue reading Please Move Inactive Files Off the /projects File System January 11, 2018 The /projects

Design and characterization of cellulose nanocrystal-enhanced epoxy hardeners

Treesearch

Shane X. Peng; Robert J. Moon; Jeffrey P. Youngblood

2014-01-01

Cellulose nanocrystals (CNCs) are renewable, sustainable, and abundant nanomaterial widely used as reinforcing fillers in the field of polymer nanocomposites. In this study, two-part epoxy systems with CNC-enhanced hardeners were fabricated. Three types of hardeners, Jeffamine D400 (JD400), diethylenetriamine (DETA), and (±)-trans-1,2- diaminocyclohexane (DACH), were...

Treatment of a Focal Articular Cartilage Defect of the Talus with Polymer-Based Autologous Chondrocyte Implantation: A 12-Year Follow-Up Period.

PubMed

Kreuz, Peter Cornelius; Kalkreuth, Richard Horst; Niemeyer, Philipp; Uhl, Markus; Erggelet, Christoph

Autologous chondrocyte implantation (ACI) is a first-line treatment option for large articular cartilage defects. Although well-established for cartilage defects in the knee, studies of the long-term outcomes of matrix-assisted ACI to treat cartilage defects in the ankle are rare. In the present report, we describe for the first time the long-term clinical and radiologic results 12 years after polymer-based matrix-assisted ACI treat a full-thickness talar cartilage defect in a 25-year-old male patient. The clinical outcome was assessed using the visual analog scale and Freiburg ankle score, magnetic resonance imaging evaluation using the Henderson-Kreuz scoring system and T2 mapping. Clinical assessment revealed improved visual analog scale and Freiburg ankle scores. The radiologic analysis and T2 relaxation time values indicated the formation of hyaline-like repair tissue. Polymer-based autologous chondrocytes has been shown to be a safe and clinically effective long-term treatment of articular cartilage defects in the talus. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

High-Performance All-Polymer Solar Cells Achieved by Fused Perylenediimide-Based Conjugated Polymer Acceptors.

PubMed

Yin, Yuli; Yang, Jing; Guo, Fengyun; Zhou, Erjun; Zhao, Liancheng; Zhang, Yong

2018-05-09

We report three n-type polymeric electron acceptors (PFPDI-TT, PFPDI-T, and PFPDI-Se) based on the fused perylene diimide (FPDI) and thieno[3,2- b]thiophene, thiophene, or selenophene units for all-polymer solar cells (all-PSCs). These FPDI-based polymer acceptors exhibit strong absorption between 350 and 650 nm with wide optical bandgap of 1.86-1.91 eV, showing good absorption compensation with the narrow bandgap polymer donor. The lowest unoccupied molecular orbital (LUMO) energy levels were located at around -4.11 eV, which are comparable with those of the fullerene derivatives and other small molecular electron acceptors. The conventional all-PSCs based on the three polymer acceptors and PTB7-Th as polymer donor gave remarkable power conversion efficiencies (PCEs) of >6%, and the PFPDI-Se-based all-PSC achieved the highest PCE of 6.58% with a short-circuit current density ( J sc ) of 13.96 mA/cm 2 , an open-circuit voltage ( V oc ) of 0.76 V, and a fill factor (FF) of 62.0%. More interestingly, our results indicate that the photovoltaic performances of the FPDI-based polymer acceptors are mainly determined by the FPDI unit with a small effect from the comonomers, which is quite different from the others reported rylenediimide-based polymer acceptors. This intriguing phenomenon is speculated as the huge geometry configuration of the FPDI unit, which minimizes the effect of the comonomer. These results highlight a promising future for the application of the FPDI-based polymer acceptors in the highly efficient all-PSCs.

Substituted amylose matrices for oral drug delivery

NASA Astrophysics Data System (ADS)

Moghadam, S. H.; Wang, H. W.; Saddar El-Leithy, E.; Chebli, C.; Cartilier, L.

2007-03-01

High amylose corn starch was used to obtain substituted amylose (SA) polymers by chemically modifying hydroxyl groups by an etherification process using 1,2-epoxypropanol. Tablets for drug-controlled release were prepared by direct compression and their release properties assessed by an in vitro dissolution test (USP XXIII no 2). The polymer swelling was characterized by measuring gravimetrically the water uptake ability of polymer tablets. SA hydrophilic matrix tablets present sequentially a burst effect, typical of hydrophilic matrices, and a near constant release, typical of reservoir systems. After the burst effect, surface pores disappear progressively by molecular association of amylose chains; this allows the creation of a polymer layer acting as a diffusion barrier and explains the peculiar behaviour of SA polymers. Several formulation parameters such as compression force, drug loading, tablet weight and insoluble diluent concentration were investigated. On the other hand, tablet thickness, scanning electron microscope analysis and mercury intrusion porosimetry showed that the high crushing strength values observed for SA tablets were due to an unusual melting process occurring during tabletting although the tablet external layer went only through densification, deformation and partial melting. In contrast, HPMC tablets did not show any traces of a melting process.

Structural properties of buried conducting layers formed by very low energy ion implantation of gold into polymer

NASA Astrophysics Data System (ADS)

Teixeira, F. S.; Salvadori, M. C.; Cattani, M.; Brown, I. G.

2009-09-01

We have investigated the fundamental structural properties of conducting thin films formed by implanting gold ions into polymethylmethacrylate (PMMA) polymer at 49 eV using a repetitively pulsed cathodic arc plasma gun. Transmission electron microscopy images of these composites show that the implanted ions form gold clusters of diameter ˜2-12 nm distributed throughout a shallow, buried layer of average thickness 7 nm, and small angle x-ray scattering (SAXS) reveals the structural properties of the PMMA-gold buried layer. The SAXS data have been interpreted using a theoretical model that accounts for peculiarities of disordered systems.

12 CFR 261a.10 - Appeal of adverse determination of request for access or amendment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of Governors of the Federal Reserve System, 20th Street and Constitution Avenue, NW., Washington, DC... access or amendment. 261a.10 Section 261a.10 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM (CONTINUED) RULES REGARDING ACCESS TO PERSONAL INFORMATION...

Dynamics of T-cell subsets and their relationship with oral and systemic opportunistic infections in HIV/AIDS patients during the first year of HAART in Guangxi, China.

PubMed

Zhang, Linlin; Huang, Yuxiao; Liu, Zhenmin; Liu, Wei; Qin, Qi; Tao, Renchuan

2015-07-01

To analyze the dynamic changes in Th1, Th2, Tc1, and Tc2 of HIV/AIDS patients during the first year of highly active antiretroviral therapy (HAART) and to explore their relationship with oral and systemic opportunistic infections, a cohort study was carried out among HIV/AIDS patients in Guangxi, China. Ninety HIV/AIDS patients and 30 healthy controls (HC) were included. The enrolled HIV/AIDS patients were examined at baseline and after 3, 6, and 12 months of HAART. On each visit, oral and systemic opportunistic infections were recorded, oral Candida load and plasma viral load (VL) were counted, differential T-cell counts and flow cytometric analysis of T-cell subsets were performed. During the first year of HAART, the total number of opportunistic infections decreased steadily with the change in oral candidiasis (OC) most representatively. A significant Th1→Th2 switch (Th1/Th2 ratio 0.23 ± 0.12, HC 1.45 ± 0.38) and slight Tc1→Tc2 shift (Tc1/Tc2 ratio 0.93 ± 0.29, HC 1.13 ± 0.33) were found at baseline, and both received slow mitigation after HAART. LgCFU and clinical OC were correlated positively with both LgVL and clinical stage (P < 0.05) at baseline. LgCFU was also correlated positively with clinical stage at all four time points (P < 0.05). In multiple factor analysis, Th1 was confirmed to be correlated negatively with LgVL (Std.B = -0.295, P = 0.025) and LgCFU (Std.B = -0.227, P < 0.001) at baseline. After HAART, LgCFU and clinical stage were only correlated negatively with CD4 when all factors were included. These results suggest that oral candidiasis and oral Candida load could be useful clinical markers in the evaluation of HIV/AIDS patients. Th1 may play an important role against oral and systemic opportunistic infections. Tc1 and Tc2 both showed positive roles in the control of viremia without HAART. J. Med. Virol. 87:1158-1167, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

System Applies Polymer Powder To Filament Tow

NASA Technical Reports Server (NTRS)

Baucom, Robert M.; Snoha, John J.; Marchello, Joseph M.

1993-01-01

Polymer powder applied uniformly and in continuous manner. Powder-coating system applies dry polymer powder to continuous fiber tow. Unique filament-spreading technique, combined with precise control of tension on fibers in system, ensures uniform application of polymer powder to web of spread filaments. Fiber tows impregnated with dry polymer powders ("towpregs") produced for preform-weaving and composite-material-molding applications. System and process valuable to prepreg industry, for production of flexible filament-windable tows and high-temperature polymer prepregs.

21 CFR 178.3505 - Glyceryl tri-(12-acetoxy-stearate).

Code of Federal Regulations, 2011 CFR

2011-04-01

... for use in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting... calcium carbonate/glyceryl tri-(12-acetoxystearate) mixture is used as an adjuvant in polymers in contact with nonfatty foods at a level not to exceed 20 weight-percent of the polymer. [50 FR 1503, Jan. 11...

Diketopyrrolopyrrole-based π-bridged donor-acceptor polymer for photovoltaic applications.

PubMed

Li, Wenting; Lee, Taegweon; Oh, Soong Ju; Kagan, Cherie R

2011-10-01

We report the synthesis, properties, and photovoltaic applications of a new conjugated copolymer (C12DPP-π-BT) containing a donor group (bithiophene) and an acceptor group (2,5-didodecylpyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione), bridged by a phenyl group. Using cyclic voltammetry, we found the energy levels of C12DPP-π-BT are intermediate to common electron donor and acceptor photovoltaic materials, poly (3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), respectively. Whereas P3HT and PCBM are exclusively electron donating or accepting, we predict C12DPP-π-BT may uniquely serve as either an electron donor or an acceptor when paired with PCBM or P3HT forming junctions with large built-in potentials. We confirmed the ambipolar nature of C12DPP-π-BT in space charge limited current measurements and in C12DPP-π-BT:PCBM and C12DPP-π-BT:P3HT bulk heterojunction solar cells, achieving power conversion efficiencies of 1.67% and 0.84%, respectively, under illumination of AM 1.5G (100 mW/cm(2)). Adding diiodooctane to C12DPP-π-BT:PCBM improved donor-acceptor inter-mixing and film uniformity, and therefore enhanced charge separation and overall device efficiency. Using higher-molecular-weight polymer C12DPP-π-BT in both C12DPP-π-BT:PCBM and C12DPP-π-BT:P3HT devices improved charge transport and hence the performance of the solar cells. In addition, we compared the structural and electronic properties of C12DPP-π-BT:PCBM and C12DPP-π-BT:P3HT blends, representing the materials classes of polymer:fullerene and polymer:polymer blends. In C12DPP-π-BT:PCBM blends, higher short circuit currents were obtained, consistent with faster charge transfer and balanced electron and hole transport, but lower open circuit voltages may be reduced by trap-assisted recombination and interfacial recombination losses. In contrast, C12DPP-π-BT:P3HT blends exhibit higher open circuit voltage, but short circuit currents were limited by charge transfer between the polymers. In conclusion, C12DPP-π-BT is a promising material with intrinsic ambipolar characteristics for organic photovoltaics and may operate as either a donor or acceptor in the design of bulk heterojunction solar cells. © 2011 American Chemical Society

Influence of hydrophilic polymers on functional properties and wound healing efficacy of hydrocolloid based wound dressings.

PubMed

Jin, Sung Giu; Yousaf, Abid Mehmood; Kim, Kyeong Soo; Kim, Dong Wuk; Kim, Dong Shik; Kim, Jin Ki; Yong, Chul Soon; Youn, Yu Seok; Kim, Jong Oh; Choi, Han-Gon

2016-03-30

The purpose of this study was to investigate the influence of different hydrophilic polymers on the swelling, bioadhesion and mechanical strength of hydrocolloid wound dressings (HCDs) in order to provide an appropriate composition for a hydrocolloid wound dressing system. In this study, the HCDs were prepared with styrene-isoprene-styrene copolymer (SIS) and polyisobutylene (PIB) as the base using a hot melting method. Additionally, numerous SIS/PIB-based HCDs were prepared with six hydrophilic polymers, and their wound dressing properties were assessed. Finally, the wound healing efficacy of the selected formulations was compared to a commercial wound dressing. The swelling ratio, bioadhesive force and mechanical strengths of HCDs were increased in the order of sodium alginate>sodium CMC=poloxamer=HPMC>PVA=PVP, sodium alginate>sodium CMC=poloxamer>PVA>HPMC=PVP and sodium alginate≥PVA>PVP=HPMC=sodium CMC>poloxamer, respectively. Among the hydrophilic polymers tested, sodium alginate most enhanced the swelling capacity, bioadhesive force and mechanical strengths. Thus, the hydrophilic polymers played great role in the swelling, bioadhesion and mechanical strength of SIS/PIB-based HCDs. The HCD formulation composed of PIB, SIS, liquid paraffin and sodium alginate at the weight ratio of 20/25/12/43 gave better wound dressing properties and more excellent wound healing efficacy than the commercial wound dressing. Therefore, the novel HCD formulation could be a promising hydrocolloid system for wound dressings. Copyright © 2016 Elsevier B.V. All rights reserved.

Naphtho[1,2-b:5,6-b']dithiophene-Based Conjugated Polymers for Fullerene-Free Inverted Polymer Solar Cells.

PubMed

Jiang, Zhaoyan; Li, Huan; Wang, Zhen; Zhang, Jianqi; Zhang, Yajie; Lu, Kun; Wei, Zhixiang

2018-03-23

Three novel copolymers based on zigzag naphthodithiophene (zNDT) with different aromatic rings as π bridges and different core side substitutions are designed and synthesized (PzNDT-T-1,3-bis(4-(2-ethylhexyl)-thiophen-2-yl)-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c']-dithiophene-4,8-dione (BDD), PzNDT-TT-BDD, and PzNDTP-T-BDD, respectively). The 2D conjugation structure and molecular planarity of the polymers can be effectively altered through the modification of conjugated side chains and π-bridges. These alterations contribute to the variation in energy levels, light absorption capacity, and morphology compatibility of the polymers. When blended with the nonfullerene acceptor (2,2'-[(4,4,9,9-tetrahexyl-4,9-dihydro-sindaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis[methylidyne(3-oxo-1H-indene-2,1(3H)-diylidene)

New Avenue for Limiting Degradation in NanoLi4Ti5O12 for Ultrafast-Charge Lithium-Ion Batteries: Hybrid Polymer-Inorganic Particles.

PubMed

Daigle, Jean-Christophe; Asakawa, Yuichiro; Beaupré, Mélanie; Vieillette, René; Laul, Dharminder; Trudeau, Michel; Zaghib, Karim

2017-12-13

Lithium titanium oxide (Li 4 Ti 5 O 12 )-based cells are a very promising battery technology for ultrafast-charge-discharge and long-cycle-life batteries. However, the surface reactivity of lithium titanium oxide in the presence of organic electrolytes continues to be a problem that may cause expansion of pouch cells. In this study, we report on the development of a simple and economical grafting method for forming hybrid polymer-Li 4 Ti 15 O 12 nanoparticles, which can be successfully applied in lithium-ion batteries. This method utilizes a low-cost and scalable hydrophobic polymer that is applicable in industrial processes. The hybrid materials demonstrated exceptional capability for preventing the degradation of cells in accelerated aging and operating over 150 cycles at 1C and 45 °C.

Microwave-Assisted Chemistry: Synthetic Applications for Rapid Assembly of Nanomaterials and Organics

EPA Science Inventory

The magic of microwave (MW) heating technique, termed as the Bunsen burner of the 21th Century, has emerged as valuable alternative in synthesis of organics, polymers, inorganics, and nanomaterials. Important innovations in MW-assisted chemistry now enable chemists to prepare cat...

12th Annual Systems Engineering Conference

DTIC Science & Technology

2009-10-29

pl em en...io n of Le sso ns L ea rn ed fr om C om pl ex S ys te m o f Sy ste m s A cq ui sit io ns D r. Ri ch ar d Tu rn er , St ev en s I ns tit ut...hn ol og y Tr an sit io n Pl an ni ng Th ro ug h th e U se o f St ag e- G at es – U pd at e M r. R an dy B ul la rd , U .S . A ir Fo

Interaction of Curcumin with PEO-PPO-PEO block copolymers: a molecular dynamics study.

PubMed

Samanta, Susruta; Roccatano, Danilo

2013-03-21

Curcumin, a naturally occurring drug molecule, has been extensively investigated for its various potential usages in medicine. Its water insolubility and high metabolism rate require the use of drug delivery systems to make it effective in the human body. Among various types of nanocarriers, block copolymer based ones are the most effective. These polymers are broadly used as drug-delivery systems, but the nature of this process is poorly understood. In this paper, we propose a molecular dynamics simulation study of the interaction of Curcumin with block copolymer based on polyethylene oxide (PEO) and polypropylene oxide (PPO). The study has been conducted considering the smallest PEO and PPO oligomers and multiple chains of the block copolymer Pluronic P85. Our study shows that the more hydrophobic 1,2-dimethoxypropane (DMP) molecules and PPO block preferentially coat the Curcumin molecule. In the case of the Pluronic P85, simulation shows formation of a drug-polymer aggregate within 50 ns. This process leaves exposed the PEO part of the polymers, resulting in better solvation and stability of the drug in water.

Resilient carbon encapsulation of iron pyrite (FeS2) cathodes in lithium ion batteries

NASA Astrophysics Data System (ADS)

Yoder, Tara S.; Tussing, Matthew; Cloud, Jacqueline E.; Yang, Yongan

2015-01-01

Converting iron pyrite (FeS2) from a non-cyclable to a cyclable cathode material for lithium ion batteries has been an ongoing challenge in recent years. Herein we report a promising mitigation strategy: wet-chemistry based conformal encapsulation of synthetic FeS2 nanocrystals in a resilient carbon (RC) matrix (FeS2@RC). The FeS2@RC composite was fabricated by dispersing autoclave-synthesized FeS2 nanocrystals in an aqueous glucose solution, polymerizing the glucose in a hydrothermal reactor, and finally heating the polymer/FeS2 composite in a tube furnace to partially carbonize the polymer. The FeS2@RC electrodes showed superior cyclability compared with the FeS2 electrodes, that is, 25% versus 1% of retention at the 20th cycle. Based on electrochemical analysis, XRD study, and SEM characterization, the performance enhancement was attributed to RC's ability to accommodate volume fluctuation, enhance charge transfer, alleviate detrimental side reactions, and suppress loss of the active material. Furthermore, the remaining issues associated with the current system were identified and future research directions were proposed.

Gold nanoparticle incorporated polymer/bioactive glass composite for controlled drug delivery application.

PubMed

Jayalekshmi, A C; Sharma, Chandra P

2015-02-01

The present study discusses the development of a biodegradable polymer encapsulated-nanogold incorporated-bioactive glass composite (AuPBG) by a low-temperature method. The composite was analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG), fluorescence and dissolution analysis. The composite exhibited aggregation behaviour in solid and solution states and exhibited negative zeta potential (-13.3 ± 1.4 mV). The composite exhibited fast degradation starting from the 5(th) day onwards in phosphate buffered saline (PBS) for a period of 14 days. The composite showed fluorescence quenching effect at pH 7 and the fluorescence recovered at pH 5. The composite has been found to be suitable for the release of doxorubicin at high rates at acidic pH (∼ 5) which is the intracellular pH of tumour cells. The drug loading ratio is also high and it exhibited a controlled release for a period of 8 days in PBS. The system serves as a promising material for targeted drug delivery applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Patterns of nocturnal rehydration in root tissues of Vaccinium corymbosum L. under severe drought conditions

PubMed Central

Valenzuela-Estrada, Luis R.; Richards, James H.; Diaz, Andres; Eissensat, David M.

2009-01-01

Although roots in dry soil layers are commonly rehydrated by internal hydraulic redistribution during the nocturnal period, patterns of tissue rehydration are poorly understood. Rates of nocturnal rehydration were examined in roots of different orders in Vaccinium corymbosum L. ‘Bluecrop’ (Northern highbush blueberry) grown in a split-pot system with one set of roots in relatively moist soil and the other set of roots in dry soil. Vaccinium is noted for a highly branched and extremely fine root system. It is hypothesized that nocturnal root tissue rehydration would be slow, especially in the distal root orders because of their greater hydraulic constraints (smaller vessel diameters and fewer number of vessels). Vaccinium root hydraulic properties delayed internal water movement. Even when water was readily available to roots in the wet soil and transpiration was minimal, it took a whole night-time period of 12 h for the distal finest roots (1st to 4th order) under dry soil conditions to reach the same water potentials as fine roots in moist soil (1st to 4th order). Even though roots under dry soil equilibrated with roots in moist soil, the equilibrium point reached before sunrise was about –1.2 MPa, indicating that tissues were not fully rehydrated. Using a single-branch root model, it was estimated that individual roots exhibiting the lowest water potentials in dry soil were 1st order roots (distal finest roots of the root system). However, considered at the branch level, root orders with the highest hydraulic resistances corresponded to the lowest orders of the permanent root system (3rd-, 4th-, and 5th-order roots), thus indicating possible locations of hydraulic safety control in the root system of this species. PMID:19188275

Patterns of nocturnal rehydration in root tissues of Vaccinium corymbosum L. under severe drought conditions.

PubMed

Valenzuela-Estrada, Luis R; Richards, James H; Diaz, Andres; Eissensat, David M

2009-01-01

Although roots in dry soil layers are commonly rehydrated by internal hydraulic redistribution during the nocturnal period, patterns of tissue rehydration are poorly understood. Rates of nocturnal rehydration were examined in roots of different orders in Vaccinium corymbosum L. 'Bluecrop' (Northern highbush blueberry) grown in a split-pot system with one set of roots in relatively moist soil and the other set of roots in dry soil. Vaccinium is noted for a highly branched and extremely fine root system. It is hypothesized that nocturnal root tissue rehydration would be slow, especially in the distal root orders because of their greater hydraulic constraints (smaller vessel diameters and fewer number of vessels). Vaccinium root hydraulic properties delayed internal water movement. Even when water was readily available to roots in the wet soil and transpiration was minimal, it took a whole night-time period of 12 h for the distal finest roots (1st to 4th order) under dry soil conditions to reach the same water potentials as fine roots in moist soil (1st to 4th order). Even though roots under dry soil equilibrated with roots in moist soil, the equilibrium point reached before sunrise was about -1.2 MPa, indicating that tissues were not fully rehydrated. Using a single-branch root model, it was estimated that individual roots exhibiting the lowest water potentials in dry soil were 1st order roots (distal finest roots of the root system). However, considered at the branch level, root orders with the highest hydraulic resistances corresponded to the lowest orders of the permanent root system (3rd-, 4th-, and 5th-order roots), thus indicating possible locations of hydraulic safety control in the root system of this species.

76 FR 51975 - Privacy Act System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-19

... FEDERAL COMMUNICATIONS COMMISSION Privacy Act System of Records AGENCY: Federal Communications... document in the Federal Register notifying the public if any changes are necessary. As required by 5 U.S.C... Records Management (PERM), Room 1-C216, Federal Communications Commission (FCC), 445 12th Street, SW...

Polymeric membrane systems of potential use for battery separators

NASA Technical Reports Server (NTRS)

Philipp, W. H.

1977-01-01

Two membrane systems were investigated that may have potential use as alkaline battery separators. One system comprises two miscible polymers: a support polymer (e.g., polyvinyl formal) and an ion conductor such as polyacrylic acid. The other system involves a film composed of two immiscible polymers: a conducting polymer (e.g., calcium polyacrylate) suspended in an inert polymer support matrix, polyphenylene oxide. Resistivities in 45-percent potassium hydroxide and qualitative mechanical properties are presented for films comprising various proportions of conducting and support polymers. In terms of these parameters, the results are encouraging for optimum ratios of conducting to support polymers.

The sociocultural effects on orthopedic surgeries in Taiwan

PubMed Central

Chiu, Shin-Lin; Chu, Chiao-Lee; Lan, Shou-Jen; Chen, Chiu-Liang

2018-01-01

Various sociocultural factors affect healthcare-seeking behaviors. In Taiwanese society, superstitions and lunar festivals play important roles in people’s lives. We investigated the impact of “Ghost Month” (the 7th lunar month) and Chinese New Year (the 12th lunar month and the 1st lunar month of the following year) on the number of elective surgeries and emergent surgeries in Taiwan. The number of total knee replacement (TKR) surgeries and proximal femur fracture (PFF) surgeries in each lunar month from 2000 to 2011 were extracted from the Taiwan National Health Insurance Database, a computerized and population-based database. Patients were then sorted by location of residence or gender. The average number of TKR surgeries performed was significantly lower during the 1st, 7th, and 12th lunar months in urban areas, whereas in rural areas this trend was only evident in the 7th and 12th lunar months. There was however, no significant difference in the average number of PFF surgeries in each lunar month except for an increase seen in the 1st lunar month in rural patients (p<0.05). When sorted by gender, the average number of TKR surgeries was significantly decreased in the 7th and 12th lunar months in male patients, and decreased in the 1st, 7th, and 12th lunar months in female patients. In contrast, there was no difference in the average numbers of PFF surgeries in the 7th and 12th lunar months either in male or female patients. We proposed that the timing of elective surgeries such as TKR might be influenced by Ghost Month and Chinese New Year; however, emergent PFF surgeries were not significantly influenced by sociocultural beliefs and taboos in Taiwan. PMID:29596539

Optimized Electroactive Polymer Supercapacitors

DTIC Science & Technology

2014-09-08

Final 03/01/2012-05/15/2014 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER OPTIMIZED ELECTROACTIVE POLYMER SUPERCAPACITORS NA Sb. GRANT NUMBER N00014-12-1...highly electroactive, conjugated polymers as the active redox materials in electrochemical supercapacitors . Such materials include electrochemically...ethylenedioxythiophene) (PEDOT) for Type I or Type II supercapacitors , along with donor-acceptor-donor (D-A-D) polymers which provide reductive states for Type

25th anniversary article: CVD polymers: a new paradigm for surface modification and device fabrication.

PubMed

Coclite, Anna Maria; Howden, Rachel M; Borrelli, David C; Petruczok, Christy D; Yang, Rong; Yagüe, Jose Luis; Ugur, Asli; Chen, Nan; Lee, Sunghwan; Jo, Won Jun; Liu, Andong; Wang, Xiaoxue; Gleason, Karen K

2013-10-11

Well-adhered, conformal, thin (<100 nm) coatings can easily be obtained by chemical vapor deposition (CVD) for a variety of technological applications. Room temperature modification with functional polymers can be achieved on virtually any substrate: organic, inorganic, rigid, flexible, planar, three-dimensional, dense, or porous. In CVD polymerization, the monomer(s) are delivered to the surface through the vapor phase and then undergo simultaneous polymerization and thin film formation. By eliminating the need to dissolve macromolecules, CVD enables insoluble polymers to be coated and prevents solvent damage to the substrate. CVD film growth proceeds from the substrate up, allowing for interfacial engineering, real-time monitoring, and thickness control. Initiated-CVD shows successful results in terms of rationally designed micro- and nanoengineered materials to control molecular interactions at material surfaces. The success of oxidative-CVD is mainly demonstrated for the deposition of organic conducting and semiconducting polymers. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dendritic Cells Induce a Subpopulation of IL-12Rβ2-Expressing Treg that Specifically Consumes IL-12 to Control Th1 Responses

PubMed Central

Sela, Uri; Park, Chae Gyu; Park, Andrew; Olds, Peter; Wang, Shu; Fischetti, Vincent A.

2016-01-01

Cytokines secreted from dendritic cells (DCs) play an important role in the regulation of T helper (Th) cell differentiation and activation into effector cells. Therefore, controlling cytokine secretion from DCs may potentially regulate Th differentiation/activation. DCs also induce de-novo generation of regulatory T cells (Treg) that modulate the immune response. In the current study we used the mixed leukocyte reaction (MLR) to investigate the effect of allospecific Treg on IL-12, TNFα and IL-6 secretion by DCs. Treg cells were found to markedly down-regulate IL-12 secretion from DCs following stimulation with TLR7/8 agonist. This down-regulation of IL-12 was neither due to a direct suppression of its production by the DCs nor a result of marked DC death. We found that IL-12 was rather actively consumed by Treg cells. IL-12 consumption was mediated by a subpopulation of IL-12Rβ2-expressing Treg cells and was dependent on MHC class-II expressed on dendritic cells. Furthermore, IL-12 consumption by Tregs increased their suppressive effect on T cell proliferation and Th1 activation. These results provide a new pathway of Th1 response regulation where IL-12 secreted by DCs is consumed by a sub-population of IL-12Rβ2-expressing Treg cells. Consumption of IL-12 by Tregs not only reduces the availability of IL-12 to Th effector cells but also enhances the Treg immunosuppressive effect. This DC-induced IL-12Rβ2-expressing Treg subpopulation may have a therapeutic advantage in suppressing Th1 mediated autoimmunity. PMID:26745371

Ocular pharmacokinetic study using T₁ mapping and Gd-chelate- labeled polymers.

PubMed

Shi, Xianfeng; Liu, Xin; Wu, Xueming; Lu, Zheng-Rong; Li, S Kevin; Jeong, Eun-Kee

2011-12-01

Recent advances in drug discovery have led to the development of a number of therapeutic macromolecules for treatment of posterior eye diseases. We aimed to investigate the clearance of macromolecular contrast probes (polymers conjugated with Gd-chelate) in the vitreous after intravitreal injections with the recently developed ms-DSEPI-T12 MRI and to examine the degradation of disulfide-containing biodegradable polymers in the vitreous humor in vivo. Intravitreal injections of model contrast agents poly[N-(2-hydroxypropyl)methacrylamide]-GG-1,6-hexanediamine-(Gd-DO3A), biodegradable (Gd-DTPA)-cystine copolymers, and MultiHance were performed in rabbits; their distribution and elimination from the vitreous after injections were determined by MRI. Times for macromolecular contrast agents to decrease to half their initial concentrations in the vitreous ranged from 0.4-1.3 days post-injection. Non-biodegradable polymers demonstrated slower vitreal clearance than those of disulfide-biodegradable polymers. Biodegradable polymers had similar clearance as MultiHance. Usefulness of T(1) mapping and ms-DSEPI-T12 MRI to study ocular pharmacokinetics was demonstrated. Results suggest an enzymatic degradation mechanism for the disulfide linkage in polymers in the vitreous leading to breakup of polymers in vitreous humor over time.

New RTM/RI Resins for the HSCT

NASA Technical Reports Server (NTRS)

Harris, Frank W.

1999-01-01

In the first portion of this work, 1,2,3,3,4,4-hexafluoro-1,2-bis[4-(dimethylhydroxysilyl)phenoxy]cyclobutane and 1,2,3,3,4,4-hexafluoro-1,2-bis[3-(dimethylhydroxysilyl)phenoxy]cyclobutane were prepared and homopolymerized to afford polymers with excellent thermal stability and Tgs of 27 C and -12 C, respectively. Despite the moderately high wt% of fluorin in the polymer structure (23.8%), these polymers had poor fuel resistance. In fact, swelling measurements indicate that these polymers had apparent solubility parameters of about 18.2 J (exp 1/2) m (exp -3/2) (toluene). Copolymerization of the disilanol monomers with fluorosilicone monomers afforded copolymers containing 20-30 wt% of the perfluorocyclobutane-containing structure displayed adequate fuel resistance, enhanced thermal stability, and a Tg low enough to meet the requirements of a High Speed Civil Transport (HSCT) fuel tank sealant. In the second part of this work, trifluorovinylether-terminated oligomers were prepared and polymerized via cyclodimerization. Initially, an alpha, omega-silanol-terminated fluorosilicone was endcapped with trifluorovinylether end groups via a two-step synthetic sequence. The oligomer was thermally cyclodimerized to a polymer that displayed thermal stability similar to that of a fluorosilicone homopolymer. Second, 1,3-bis[4-trifluorovinyl(oxy)phenyl]-1,3-(3,3,3-trifluoropropyl)dimethyldisiloxane and 1,3-bis{3-trifluorovinyl(oxy)phenyl]-1,3-(3,3,3-trifluoropropyl)dimethyldisiloxane were prepared and cyclodimerized to afford polymers that contained pendant trifluoropropyl groups. The pendant trifluoropropyl groups did enhance solvent resistance in aliphatic hydrocarbon solvents, however, no improvement was observed in aromatic hydrocarbon solvents. These polymers also displayed excellent thermal stability. In the last part of this work, a series of monomers was prepared by the DCC-promoted esterification of 4-[trifluorovinyl(oxy)benzoic acid with alpha, omega-functionalized hydrogenated and partially fluorinated alcohols. The monomers were cyclodimerized to the corresponding polymers. The polymers that did not contain beta hydrogens displayed significantly higher thermal stability than the fully hydrogenated polymers. A commercially-available alpha,omega-hydroxy-terminated perfluoropolyether was then functionalized with 4-[trifluorovinyl(oxy)benzoylchloride. An attempt was made to polymerize the resulting oligomer via the cyclodimerization of the terminal trifluorovinylether moieties. Although the viscosity of the oligomer increased significantly during polymerization, Gel Permeation Chromatography (GPC) analysis revealed that the Tetrahydrofuran (THF) soluble portion of the polymer did not have high molecular weight.

Effects of Low-Intensity Pulsed Ultrasound on Implant Osseointegration in Ovariectomized Rats.

PubMed

Zhou, Hongbo; Hou, Yongfu; Zhu, Zhimin; Xiao, Weixiong; Xu, Qian; Li, Lei; Li, Xin; Chen, Wenchuan

2016-04-01

To investigate the effect of low-intensity pulsed ultrasound (US) on periimplant bone healing and osseointegration under osteoporotic conditions. Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm2, spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0–2, 280 minutes; group 2: weeks 0–4, 560 minutes; group 3: weeks 0–6, 840 minutes; group 4: weeks 0–8, 1120 minutes; group 5: weeks 0–10, 1400 minutes; group 6: weeks 0–12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro–computed tomography; the implantbone interface was assessed histologically; and implant fixation strength was determined by a removal torque test. Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and periimplant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study. Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action.

Effects of Low-Intensity Pulsed Ultrasound on Implant Osseointegration in Ovariectomized Rats.

PubMed

Zhou, Hongbo; Hou, Yongfu; Zhu, Zhimin; Xiao, Weixiong; Xu, Qian; Li, Lei; Li, Xin; Chen, Wenchuan

2016-04-01

To investigate the effect of low-intensity pulsed ultrasound (US) on peri-implant bone healing and osseointegration under osteoporotic conditions. Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm 2 , spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0-2, 280 minutes; group 2: weeks 0-4, 560 minutes; group 3: weeks 0-6, 840 minutes; group 4: weeks 0-8, 1120 minutes; group 5: weeks 0-10, 1400 minutes; group 6: weeks 0-12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro-computed tomography; the implant-bone interface was assessed histologically; and implant fixation strength was determined by a removal torque test. Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and peri-implant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study. Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action. © 2016 by the American Institute of Ultrasound in Medicine.

High-Performance Flexible Solid-State Supercapacitor with an Extended Nanoregime Interface through in Situ Polymer Electrolyte Generation.

PubMed

Anothumakkool, Bihag; Torris A T, Arun; Veeliyath, Sajna; Vijayakumar, Vidyanand; Badiger, Manohar V; Kurungot, Sreekumar

2016-01-20

Here, we report an efficient strategy by which a significantly enhanced electrode-electrolyte interface in an electrode for supercapacitor application could be accomplished by allowing in situ polymer gel electrolyte generation inside the nanopores of the electrodes. This unique and highly efficient strategy could be conceived by judiciously maintaining ultraviolet-triggered polymerization of a monomer mixture in the presence of a high-surface-area porous carbon. The method is very simple and scalable, and a prototype, flexible solid-state supercapacitor could even be demonstrated in an encapsulation-free condition by using the commercial-grade electrodes (thickness = 150 μm, area = 12 cm(2), and mass loading = 7.3 mg/cm(2)). This prototype device shows a capacitance of 130 F/g at a substantially reduced internal resistance of 0.5 Ω and a high capacitance retention of 84% after 32000 cycles. The present system is found to be clearly outperforming a similar system derived by using the conventional polymer electrolyte (PVA-H3PO4 as the electrolyte), which could display a capacitance of only 95 F/g, and this value falls to nearly 50% in just 5000 cycles. The superior performance in the present case is credited primarily to the excellent interface formation of the in situ generated polymer electrolyte inside the nanopores of the electrode. Further, the interpenetrated nature of the polymer also helps the device to show a low electron spin resonance and power rate and, most importantly, excellent shelf-life in the unsealed flexible conditions. Because the nature of the electrode-electrolyte interface is the major performance-determining factor in the case of many electrochemical energy storage/conversion systems, along with the supercapacitors, the developed process can also find applications in preparing electrodes for the devices such as lithium-ion batteries, metal-air batteries, polymer electrolyte membrane fuel cells, etc.

Lipid and Lipid-Polymer Mixtures at an Interface

NASA Astrophysics Data System (ADS)

Kim, Joon Heon; Kim, Mahn Won

2000-03-01

The surface pressure (Π) and surface area/molecule (A) isotherms of a mixture of DMPC (DL-α-phosphatidylcholine,Dimyristoyl) and PEG-DMPE (1,2-Diacyl-sn-Glycero-3-Phosphoethanolamine-N-[Poly(ethylene glycol)5000]) system were measured at various compositions by the Langmuir surface balance technique at an air/water interface. In the range where the surface pressure is less than about 8 dynes/cm, a PEG polymer chain of PEG-DMPE molecules remains on the surface and the isotherm can be explained by the 2-D power law behavior of chains in a good solvent. In the range above 8 dynes/cm, a part of the PEG polymer segment is dissolved into the water phase, and the surface pressure can be explained as the sum of the 2-D component and 3-D component. Furthermore, the mixing energy is negative, which indicates an attractive interaction between DMPC and PEG-DMPE.

Lipid and lipid-polymer mixtures at an interface

NASA Astrophysics Data System (ADS)

Kim, Joon Heon; Kim, Mahn Won

2000-06-01

The surface pressure (Π) and surface area/molecule (A) isotherms of a mixture of DMPC (DL-α-phosphatidylcholine, Dimyristoyl) and PEG-DMPE (1,2-Diacyl-sn-Glycero-3-Phosphoethanolamine-N-[Poly(ethylene glycol)5000]) system were measured at various compositions by the Langmuir surface balance technique at an air/water interface. In the range where the surface pressure is less than about 8 dynes/cm, a PEG polymer chain of PEG-DMPE molecules remains on the surface and the isotherm can be explained by the 2-D power law behavior of chains in a good solvent. In the range above 8 dynes/cm, a part of the PEG polymer segment is dissolved into the water phase, and the surface pressure can be explained as the sum of the 2-D component and 3-D component. Furthermore, the mixing energy is negative, which indicates an attractive interaction between DMPC and PEG-DMPE. .

A Preliminary Study on the Toxic Combustion Products Testing of Polymers Used in High-Pressure Oxygen Systems

NASA Technical Reports Server (NTRS)

Hshieh, Fu-Yu; Beeson, Harold D.

2004-01-01

One likely cause of polymer ignition in a high-pressure oxygen system is adiabatic-compression heating of polymers caused by pneumatic impact. Oxidative _ pyrolysis or combustion of polymers in a high-pressure oxygen system could generate toxic gases. This paper reports the preliminary results of toxic combustion product testing of selected polymers in a pneumatic-impact test system. Five polymers commonly used in high-pressure oxygen systems, Nylon 6/6, polychlorotrifluoroethylene (CTFE), polytetrafluoroethylene (PTFE), fluoroelastomer (Viton(TradeMark) A), and nitrile rubber (Buna N), were tested in a pneumatic-impact test system at 2500- or 3500-psia oxygen pressure. The polymers were ignited and burned, then combustion products were collected in a stainless-steel sample bottle and analyzed by GC/MS/IRD, GC/FID, and GC/Methanizer/FID. The results of adiabatic-compression tests show that combustion of hydrocarbon polymers, nitrogen-containing polymers, and halogenated polymers in high-pressure oxygen systems are relatively complete. Toxicity of the combustion product gas is presumably much lower than the combustion product gas generated from ambient-pressure oxygen (or air) environments. The NASA-Lewis equilibrium code was used to determine the composition of combustion product gas generated from a simulated, adiabatic-compression test of nine polymers. The results are presented and discussed.

Transforming growth factor-beta controls T helper type 1 cell development through regulation of natural killer cell interferon-gamma.

PubMed

Laouar, Yasmina; Sutterwala, Fayyaz S; Gorelik, Leonid; Flavell, Richard A

2005-06-01

Interferon-gamma and interleukin 12 produced by the innate arm of the immune system are important regulators of T helper type 1 (T(H)1) cell development, but signals that negatively regulate their expression remain controversial. Here we show that transforming growth factor-beta (TGF-beta) controlled T(H)1 differentiation through the regulation of interferon-gamma produced by natural killer (NK) cells. Blockade of TGF-beta signaling in NK cells caused the accumulation of a large pool of NK cells secreting copious interferon-gamma, responsible for T(H)1 differentiation and protection from leishmania infection. In contrast, blockade of TGF-beta signaling in dendritic cells did not affect dendritic cell homeostasis or interleukin 12 production, thus indicating a previously undescribed demarcation of the function of TGF-beta in NK cells versus dendritic cells.

Automated sorting of polymer flakes: fluorescence labeling and development of a measurement system prototype.

PubMed

Brunner, S; Fomin, P; Kargel, Ch

2015-04-01

The extensive demand and use of plastics in modern life is associated with a significant economical impact and a serious ecological footprint. The production of plastics involves a high energy consumption and CO2 emission as well as the large need for (limited) fossil resources. Due to the high durability of plastics, large amounts of plastic garbage is mounting in overflowing landfills (plus 9.6 million tons in Europe in the year 2012) and plastic debris is floating in the world oceans or waste-to-energy combustion releases even more CO2 plus toxic substances (dioxins, heavy metals) to the atmosphere. The recycling of plastic products after their life cycle can obviously contribute a great deal to the reduction of the environmental and economical impacts. In order to produce high-quality recycling products, mono-fractional compositions of waste polymers are required. However, existing measurement technologies such as near infrared spectroscopy show limitations in the sorting of complex mixtures and different grades of polymers, especially when black plastics are involved. More recently invented technologies based on mid-infrared, Raman spectroscopy or laser-aided spectroscopy are still under development and expected to be rather expensive. A promising approach to put high sorting purities into practice is to label plastic resins with unique combinations of fluorescence markers (tracers). These are incorporated into virgin resins during the manufacturing process at the ppm (or sub ppm) concentration level, just large enough that the fluorescence emissions can be detected with sensitive instrumentation but neither affect the visual appearance nor the mechanical properties of the polymers. In this paper we present the prototype of a measurement and classification system that identifies polymer flakes (mill material of a few millimeters size) located on a conveyor belt in real time based on the emitted fluorescence of incorporated markers. Classification performance and throughput were experimentally quantified using 3 different types of polymers (Polyoxymethylene (POM), Polybutylenterephthalat (PBT) and Acrylonitrile Styrene Acrylate (ASA)) in colored and uncolored form. Overall, 12 classes of plastic flakes were investigated in this study, where 11 classes were labeled with unique binary combinations of 4 fluorescence markers and class 12 includes unlabeled plastic flakes of various colors. From approx. 68,000 investigated flakes it was found that the developed measurement prototype system achieves an average sensitivity (true positive rate) of 99.4% and a precision (positive predictive value) of 99.5%, while being able to handle up to approx. 1800 flakes per second. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecularly Engineered Polymer-Based Systems in Drug Delivery and Regenerative Medicine.

PubMed

Piluso, Susanna; Soultan, Al Halifa; Patterson, Jennifer

2017-01-01

Polymer-based systems are attractive in drug delivery and regenerative medicine due to the possibility of tailoring their properties and functions to a specific application. The present review provides several examples of molecularly engineered polymer systems, including stimuli responsive polymers and supramolecular polymers. The advent of controlled polymerization techniques has enabled the preparation of polymers with controlled molecular weight and well-defined architecture. By using these techniques coupled to orthogonal chemical modification reactions, polymers can be molecularly engineered to incorporate functional groups able to respond to small changes in the local environment or to a specific biological signal. This review highlights the properties and applications of stimuli-responsive systems and polymer therapeutics, such as polymer-drug conjugates, polymer-protein conjugates, polymersomes, and hyperbranched systems. The applications of polymeric membranes in regenerative medicine are also discussed. The examples presented in this review suggest that the combination of membranes with polymers that are molecularly engineered to respond to specific biological functions could be relevant in the field of regenerative medicine. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Preparation of sildenafil citrate microcapsules and in vitro/in vivo evaluation of taste masking efficiency.

PubMed

Yi, Eun-Jin; Kim, Ju-Young; Rhee, Yun-Seok; Kim, Su-Hyeon; Lee, Hyo-Joong; Park, Chun-Woong; Park, Eun-Seok

2014-05-15

The aim of the present study was to prepare the particulate taste-masking system to mask the bitter taste of sildenafil citrate (SC), a well-known phosphodiesterase-5 inhibitor used for erectile dysfunction (ED) and pulmonary artery hypertension (PAH). It was evaluated for the taste masking efficiency by the in vitro measurement using electronic tongue (e-tongue) system and the in vivo human panel sensory test. Microcapsules were prepared by microencapsulation with a gastro-soluble polymer, Eudragit(®) E100 (E100), using a spray drying technique at four different weight ratios (2:1, 1:1, 1:2, and 1:3). Characters of prepared microcapsules and the effect of polymer ratio on the taste masking were investigated. The particle morphology and the distribution of SC in microcapsules were observed by SEM-EDS and physical properties were evaluated by PXRD, Raman spectroscopy, and DSC. By drug dissolution studies at pH 1.2 buffer and DW, it was found that E100 was not able to alter the drug release in stomach. As the result of taste evaluation studies, there were a good correlation (R(2)=0.9867) between the weight ratio of polymer and the taste masking efficiency expressed in the distances on the PCA map of the e-tongue data, and a relevance of the e-tongue measurement with the result of sensory test. Copyright © 2014. Published by Elsevier B.V.

In Situ Porous Structures: A Unique Polymer Erosion Mechanism in Biodegradable Dipeptide-based Polyphosphazene and Polyester Blends Producing Matrices for Regenerative Engineering

PubMed Central

Deng, Meng; Nair, Lakshmi S.; Nukavarapu, Syam P.; Kumbar, Sangamesh G.; Jiang, Tao; Weikel, Arlin L.; Krogman, Nicholas R.; Allcock, Harry R.; Laurencin, Cato T.

2011-01-01

Synthetic biodegradable polymers serve as temporary substrates that accommodate cell infiltration and tissue in-growth in regenerative medicine. To allow tissue in-growth and nutrient transport, traditional three-dimensional (3D) scaffolds must be prefabricated with an interconnected porous structure. Here we demonstrated for the first time a unique polymer erosion process through which polymer matrices evolve from a solid coherent film to an assemblage of microspheres with an interconnected 3D porous structure. This polymer system was developed on the highly versatile platform of polyphosphazene-polyester blends. Co-substituting a polyphosphazene backbone with both hydrophilic glycylglycine dipeptide and hydrophobic 4-phenylphenoxy group generated a polymer with strong hydrogen bonding capacity. Rapid hydrolysis of the polyester component permitted the formation of 3D void space filled with self-assembled polyphosphazene spheres. Characterization of such self-assembled porous structures revealed macropores (10-100 μm) between spheres as well as micro- and nanopores on the sphere surface. A similar degradation pattern was confirmed in vivo using a rat subcutaneous implantation model. 12 weeks of implantation resulted in an interconnected porous structure with 82-87% porosity. Cell infiltration and collagen tissue in-growth between microspheres observed by histology confirmed the formation of an in situ 3D interconnected porous structure. It was determined that the in situ porous structure resulted from unique hydrogen bonding in the blend promoting a three-stage degradation mechanism. The robust tissue in-growth of this dynamic pore forming scaffold attests to the utility of this system as a new strategy in regenerative medicine for developing solid matrices that balance degradation with tissue formation. PMID:21789036

Alpha-2A Adrenoceptor Agonist Guanfacine Restores Diuretic Efficiency in Experimental Cirrhotic Ascites: Comparison with Clonidine

PubMed Central

Sansoè, Giovanni; Aragno, Manuela; Mastrocola, Raffaella; Mengozzi, Giulio; Parola, Maurizio

2016-01-01

Background In human cirrhosis, adrenergic hyperfunction causes proximal tubular fluid retention and contributes to diuretic-resistant ascites, and clonidine, a sympatholytic drug, improves natriuresis in difficult-to-treat ascites. Aim To compare clonidine (aspecific α2-adrenoceptor agonist) to SSP-002021R (prodrug of guanfacine, specific α2A-receptor agonist), both associated with diuretics, in experimental cirrhotic ascites. Methods and Results Six groups of 12 rats were studied: controls (G1); controls receiving furosemide and potassium canrenoate (G2); rats with ascitic cirrhosis due to 14-week CCl4 treatment (G3); cirrhotic rats treated (over the 11th-14th CCl4 weeks) with furosemide and canrenoate (G4), furosemide, canrenoate and clonidine (G5), or diuretics and SSP002021R (G6). Three rats of each group had their hormonal status and renal function assessed at the end of 11th, 12th, 13th, and 14th weeks of respective treatments.Cirrhotic rats in G3 and G4 gained weight over the 12th-14th CCl4 weeks. In G4, brief increase in sodium excretion over the 11th-12th weeks preceded worsening of inulin clearance and natriuresis (diuretic resistance). In comparison with G4, the addition of clonidine (G5) or guanfacine (G6) to diuretics improved, respectively, sodium excretion over the 11th-12th CCl4 weeks, or GFR and electrolytes excretion over the 13th-14th CCl4 weeks. Natriuretic responses in G5 and G6 were accompanied by reduced catecholamine serum levels. Conclusions α2A-receptor agonists restore glomerular filtration rate and natriuresis, and delay diuretic-resistant ascites in experimental advanced cirrhosis. Clonidine ameliorates diuretic-dependent natriuresis just for a short time. PMID:27384184

Asymmetric Alkyl Side-Chain Engineering of Naphthalene Diimide-Based n-Type Polymers for Efficient All-Polymer Solar Cells.

PubMed

Jia, Tao; Li, Zhenye; Ying, Lei; Jia, Jianchao; Fan, Baobing; Zhong, Wenkai; Pan, Feilong; He, Penghui; Chen, Junwu; Huang, Fei; Cao, Yong

2018-02-13

The design and synthesis of three n-type conjugated polymers based on a naphthalene diimide-thiophene skeleton are presented. The control polymer, PNDI-2HD, has two identical 2-hexyldecyl side chains, and the other polymers have different alkyl side chains; PNDI-EHDT has a 2-ethylhexyl and a 2-decyltetradecyl side chain, and PNDI-BOOD has a 2-butyloctyl and a 2-octyldodecyl side chain. These copolymers with different alkyl side chains exhibit higher melting and crystallization temperatures, and stronger aggregation in solution, than the control copolymer PNDI-2HD that has the same side chain. Polymer solar cells based on the electron-donating copolymer PTB7-Th and these novel copolymers exhibit nearly the same open-circuit voltage of 0.77 V. Devices based on the copolymer PNDI-BOOD with different side chains have a power-conversion efficiency of up to 6.89%, which is much higher than the 4.30% obtained with the symmetric PNDI-2HD. This improvement can be attributed to the improved charge-carrier mobility and the formation of favorable film morphology. These observations suggest that the molecular design strategy of incorporating different side chains can provide a new and promising approach to developing n-type conjugated polymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exposure to Palladium Nanoparticles Affects Serum Levels of Cytokines in Female Wistar Rats

PubMed Central

Iavicoli, Ivo; Fontana, Luca; Corbi, Maddalena; Leso, Veruscka; Marinaccio, Alessandro; Leopold, Kerstin; Schindl, Roland; Sgambato, Alessandro

2015-01-01

Background Information currently available on the impact of palladium on the immune system mainly derives from studies assessing the biological effects of palladium salts. However, in the last years, there has been a notable increase in occupational and environmental levels of fine and ultrafine palladium particles released from automobile catalytic converters, which may play a role in palladium sensitization. In this context, the evaluation of the possible effects exerted by palladium nanoparticles (Pd-NPs) on the immune system is essential to comprehensively assess palladium immunotoxic potential. Aim Therefore, the aim of this study was to investigate the effects of Pd-NPs on the immune system of female Wistar rats exposed to this xenobiotic for 14 days, by assessing possible quantitative changes in a number of cytokines: IL-1α, IL-2, IL-4, IL-6, IL-10, IL-12, GM-CSF, INF-γ and TNF-α. Methods Twenty rats were randomly divided into four exposure groups and one of control. Animals were given a single tail vein injection of vehicle (control group) and different concentrations of Pd-NPs (0.012, 0.12, 1.2 and 12 μg/kg). A multiplex biometric enzyme linked immunosorbent assay was used to evaluate cytokine serum levels. Results The mean serum concentrations of all cytokines decreased after the administration of 0.012 μg/kg of Pd-NPs, whereas exceeded the control levels at higher exposure doses. The highest concentration of Pd-NPs (12 μg/kg) induced a significant increase of IL-1α, IL-4, IL-6, IL-10, IL-12, GM-CSF and INF-γ compared to controls. Discussion and Conclusions These results demonstrated that Pd-NP exposure can affect the immune response of rats inducing a stimulatory action that becomes significant at the highest administered dose. Our findings did not show an imbalance between cytokines produced by CD4+ T helper (Th) cells 1 and 2, thus suggesting a generalized stimulation of the immune system with a simultaneous activation and polarization of the naïve T cells towards Th1 and Th2 phenotype. PMID:26618704

Characterization of charged polymer self-assemblies by multidetector thermal field-flow fractionation in aqueous mobile phases.

PubMed

Greyling, Guilaume; Pasch, Harald

2018-01-12

Charged block copolymer self-assemblies, such as charged micelles, have attracted much attention as versatile drug delivery systems due to their readily tunable characteristics such as size and surface charge. However, current column-based analytical techniques are not suitable to fractionate and comprehensively characterize charged micelles in terms of size, molar mass, chemical composition and morphology. Multidetector thermal field-flow fractionation (ThFFF) is shown to be a unique characterization platform that can be used to characterize charged micelles in terms of size, molar mass, chemical composition and morphology in aqueous mobile phases with various ionic strengths and pH. This is demonstrated by the characterization of poly(methacrylic acid)-b-poly(methyl methacrylate) self-assemblies in high pH buffers as well as the characterization of cationic poly(2-vinyl pyridine)-b-polystyrene and poly(4-vinyl pyridine)-b-polystyrene self-assemblies in low pH buffers. Moreover, it is shown that ThFFF is capable of separating charged micelles according to the corona composition. These investigations prove convincingly that ThFFF is broadly applicable to the comprehensive characterization of amphiphilic self-assemblies even when aqueous mobile phases are used. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of fibre and filler reinforcement of plastic brackets: an in vitro study.

PubMed

Faltermeier, Andreas; Rosentritt, Martin; Faltermeier, Rupert; Müssig, Dieter

2007-06-01

In spite of their popularity in fulfilling aesthetic requirements, plastic brackets still present some disadvantages because of their low elastic modulus, decreased fracture toughness, and reduced wear resistance. Fibre-reinforced composites are well established in dentistry and consist of a polymer matrix in which reinforcing fibres are embedded. Stress is transferred from the polymer matrix to the fibres which present a high tensile strength. Hence, the mechanical properties of polymers could be improved. The purpose of this study was to compare fracture strength, fracture toughness and flexural strength of an experimental fibre-reinforced bracket material, an SiO(2) filler-reinforced bracket and an unfilled plastic bracket material (control group). Experimental brackets and specialized bars were manufactured. Tests were performed after thermal cycling (5 degrees C/55 degrees C) the samples in an artificial oral environment of a device to simulate mastication. Statistical evaluation was undertaken. The median, 25th and 75th percentiles were calculated and a Mann-Whitney U-test was performed. In this study two findings were obvious. (1) Filler reinforcement of plastic brackets improved fracture strength and fracture toughness in comparison with the unfilled bracket material. (2) Glass fibre reinforcement of orthodontic bracket materials resulted in the greatest enhancement of the mechanical properties in comparison with the other test groups. Therefore, the application of glass fibres in plastic brackets is a successful method to enhance fracture strength.

Proceedings of the 10th international symposium on polymer surface modification

USDA-ARS?s Scientific Manuscript database

Contamination of meats, seafood, poultry, eggs, and fresh and fresh-cut fruits and vegetables is an ongoing concern. Although well-established in non-food applications for surface treatment and modification, cold plasma is a relatively new food safety intervention. As a nonthermal food processing te...

Fuel Cells Using the Protic Ionic Liquid and Rotator Phase Solid Electrolyte Principles

DTIC Science & Technology

2008-02-13

Talk “High temperature Polymer Electrolyte Membrane Fuel Cells (HT- PEMFCs ) for Portable Power in Large-Scale Energy Storage Devices”, Paper Number 195...Membrane Fuel Cells (HT- PEMFCs ) for Portable Power in Large-Scale Energy Storage Devices”, Paper Number 195, 212th Meeting of the Electrochemical

Advanced Electronics Systems 1, Industrial Electronics 3: 9327.03.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

The 135 clock-hour course for the 12th year consists of outlines for blocks of instruction on transistor applications to basic circuits, principles of single sideband communications, maintenance practices, preparation for FCC licenses, application of circuits to advanced electronic systems, nonsinusoidal wave shapes, multivibrators, and blocking…

Green polymer chemistry: investigating the mechanism of radical ring-opening redox polymerization (R3P) of 3,6-dioxa-1,8-octanedithiol (DODT).

PubMed

Rosenthal-Kim, Emily Q; Puskas, Judit E

2015-04-13

The mechanism of the new Radical Ring-opening Redox Polymerization (R3P) of 3,6-dioxa-1,8-octanedithiol (DODT) by triethylamine (TEA) and dilute H2O2 was investigated. Scouting studies showed that the formation of high molecular weight polymers required a 1:2 molar ratio of DODT to TEA and of DODT to H2O2. Further investigation into the chemical composition of the organic and aqueous phases by 1H-NMR spectroscopy and mass spectrometry demonstrated that DODT is ionized by two TEA molecules (one for each thiol group) and thus transferred into the aqueous phase. The organic phase was found to have cyclic disulfide dimers, trimers and tetramers. Dissolving DODT and TEA in water before the addition of H2O2 yielded a polymer with Mn = 55,000 g/mol, in comparison with Mn = 92,000 g/mol when aqueous H2O2 was added to a DODT/TEA mixture. After polymer removal, MALDI-ToF MS analysis of the residual reaction mixtures showed only cyclic oligomers remaining. Below the LCST for TEA in water, 18.7 °C, the system yielded a stable emulsion, and only cyclic oligomers were found. Below DODT/TEA and H2O2 1:2 molar ratio mostly linear oligomers were formed, with <20% cyclic oligomers. The findings support the proposed mechanism of R3P.

Evaluation of in vitro spermatogenesis system effectiveness to study genes behavior: monitoring the expression of the testis specific 10 (Tsga10) gene as a model.

PubMed

Miryounesi, Mohammad; Nayernia, Karim; Mobasheri, Maryam Beigom; Dianatpour, Mahdi; Oko, Richard; Savad, Shahram; Modarressi, Mohammad Hossein

2014-10-01

In vitro generation of germ cells introduces a novel approach to male infertility and provides an effective system in gene tracking studies, however many aspects of this process have remained unclear. We aimed to promote mouse embryonic stem cells (mESC) differentiation into germ cells and evaluate its effectiveness with tracking the expression of the Tsga10 during this process. mESCs were differentiated into germ cells in the presence of Retinoic Acid. Based on developmental schedule of the postnatal testis, samples were taken on the 7th, 12th, and 25th days of the culture and were subjected to expression analysis of a panel of germ cell specific genes. Expression of Tsga10 in RNA and protein levels was then analyzed. Transition from mitosis to meiosis occurred between 7th and 12th days of mESC culture and post-meiotic gene expression did not occur until the 25th day of the culture. Results showed low level of Tsga10expression in undifferentiated stem cells. During transition from meiotic to post-meiotic phase, Tsga10 expression increased in 6.6 folds. This finding is in concordance with in vivo changes during transition from pre-pubertal to pubertal stage. Localization of processed and unprocessed forms of the related protein was similar to those in vivo as well. Expression pattern of Tsga10, as a gene with critical function in spermatogenesis, is similar during in vitro and in vivo germ cell generation. The results suggest that in vitro derived germ cells could be a trusted model to study genes behavior during spermatogenesis.

26th JANNAF Airbreathing Propulsion Subcommittee Meeting. Volume 1

NASA Technical Reports Server (NTRS)

Fry, Ronald S. (Editor); Gannaway, Mary T. (Editor)

2002-01-01

This volume, the first of four volumes, is a collection of 28 unclassified/unlimited-distribution papers which were presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 26th Airbreathing Propulsion Subcommittee (APS) was held jointly with the 38th Combustion Subcommittee (CS), 20th Propulsion Systems Hazards Subcommittee (PSHS), and 2nd Modeling and Simulation Subcommittee. The meeting was held 8-12 April 2002 at the Bayside Inn at The Sandestin Golf & Beach Resort and Eglin Air Force Base, Destin, Florida. Topics covered include: scramjet and ramjet R&D program overviews; tactical propulsion; space access; NASA GTX status; PDE technology; actively cooled engine structures; modeling and simulation of complex hydrocarbon fuels and unsteady processes; and component modeling and simulation.

75 FR 71688 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-24

... polyalkylene oxide. P-10-0575 09/27/10 12/25/10 Eastman Kodak (S) Polymer used in (G) Methacrylic acid Company. manufacture of polymer with imaging media/ isoalkylmethacrylam products; for ide, export. arylmethacrylate...) industrial coatings. Alkylenealkanedioic acid, polymer with alkenylbenzene and alkenenitrile, ammonium salt...

Effect of molecular conformation on the mechanofluorochromic properties based on DDIF

NASA Astrophysics Data System (ADS)

Mai, Runsheng; Peng, Huojun; Meng, Yuying; Chang, Xinyue; Jiang, Yue; Gao, Jinwei; Zhou, Guofu; Liu, Jun-ming

2017-07-01

Mechanofluorochromic (MFC) materials are smart materials in that their absorption and/or emission can respond to mechanical stimuli. They have received much attention recently. Although there have been several new material systems designed, little work has been done regarding the influence of molecular conformation on MFC properties. Herein, to disclose the relationship between molecular conformation and MFC properties, two molecules based on a 6, 12-Dihydro-6, 12-diaza-indeno[1,2-b]fluorine (DDIF) building block with thienyl linker, BDDIF-Th and BDDIF-BTh, have been designed and synthesized. Optical and electrochemical properties have been studied by UV-vis spectrometer and cyclic voltammetry measurements. Weak aggregation-induced emission (AIE) phenomena were obtained in the tetrahydrofuran (THF)/water solution. MFC behaviors suggest that BDDIF-Th is more sensible to the external mechanical forces than BDDIF-BTh. The color change could be attributed to the appearance of new emission peak instead of a bathochromic or hypsochromic effect. Theoretical calculations reveal that MFC performance is highly related to the molecular conformation, meaning that the BDDIF-BTh with perpendicular conformation is more difficult to flatten than the comparatively planar BDDIF-Th.

Topological Constraints in Directed Polymer Melts.

PubMed

Serna, Pablo; Bunin, Guy; Nahum, Adam

2015-11-27

Polymers in a melt may be subject to topological constraints, as in the example of unlinked polymer rings. How to do statistical mechanics in the presence of such constraints remains a fundamental open problem. We study the effect of topological constraints on a melt of directed polymers, using simulations of a simple quasi-2D model. We find that fixing the global topology of the melt to be trivial changes the polymer conformations drastically. Polymers of length L wander in the transverse direction only by a distance of order (lnL)^{ζ} with ζ≃1.5. This is strongly suppressed in comparison with the Brownian L^{1/2} scaling which holds in the absence of the topological constraint. It is also much smaller than the predictions of standard heuristic approaches-in particular the L^{1/4} of a mean-field-like "array of obstacles" model-so our results present a sharp challenge to theory. Dynamics are also strongly affected by the constraints, and a tagged monomer in an infinite system performs logarithmically slow subdiffusion in the transverse direction. To cast light on the suppression of the strands' wandering, we analyze the topological complexity of subregions of the melt: the complexity is also logarithmically small, and is related to the wandering by a power law. We comment on insights the results give for 3D melts, directed and nondirected.

Synthesis of metronidazole-imprinted molecularly imprinted polymers by distillation precipitation polymerization and their use as a solid-phase adsorbent and chromatographic filler.

PubMed

Liu, Jiang; Zhang, Lu; Li Han Song, Le; Liu, Yuan; Tang, Hui; Li, Yingchun

2015-04-01

Metronidazole-imprinted polymers with superior recognition properties were prepared by a novel strategy called distillation-precipitation polymerization. The as-obtained polymers were characterized by Fourier-transform infrared spectroscopy, laser particle size determination and scanning electron microscopy, and their binding performances were evaluated in detail by static, kinetic and dynamic rebinding tests, and Scatchard analysis. The results showed that when the fraction of the monomers was 5 vol% in the whole reaction system, the prepared polymers afforded good morphology, monodispersity, and high adsorption capacity and excellent selectivity to the target molecule, metronidazole. The optimal binding performance is 12.41 mg/g for metronidazole just before leakage occurred and 38.51 mg/g at saturation in dynamic rebinding tests. Metronidazole-imprinted polymers were further applied as packing agents in solid-phase extraction and as chromatographic filler, both of which served for the detection of metronidazole in fish tissue. The results illustrated the recoveries of spiked samples ranged from 82.97 to 87.83% by using molecularly imprinted solid-phase extraction combined with a C18 commercial column and 93.7 to 101.2% by directly using the polymer-packed chromatographic column. The relative standard deviation of both methods was less than 6%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unbinding transition from fluid membranes with associated polymers.

PubMed

Benhamou, M; Kaidi, H

2013-10-01

We consider two neighboring fluid membranes that are associated with long flexible polymers (proteins or other macromolecules). We are interested in two physical systems consisting of i) two adjacent membranes with end-grafted (or adsorbed) polymers (system I), or ii) two membranes confining a polymer solution (system II). In addition to the pure interactions between membranes, the presence of polymers gives rise to new induced mediated interactions, which are repulsive, for system I, and attractive, for system II. In fact, repulsive induced interactions are caused by the excluded-volume forces between grafted polymers, while attractive ones, by entropy loss, due to free motion of polymers between membranes. The main goal is a quantitative study of the unbinding transition thermodynamics that is drastically affected by the associated polymers. For system I, the repulsive polymer-mediated force delays this transition that can happen at low temperature. To investigate the unbinding phenomenon, we first present an exact mathematical analysis of the total potential that is the sum of the primitive and induced potentials. This mathematical study enables us to classify the total interaction potentials, in terms of all parameters of the problem. Second, use is made of the standard variational method to calculate the first moments of the membrane separation. Special attention is paid to the determination of the unbinding temperature. In particular, we discuss its dependence on the extra parameters related to the associated polymers, which are the surface coverage and the polymer layer thickness on each membrane (for system I) or the polymer density and the gyration radius of coils (for system II). Third, we compute the disjoining pressure upon membrane separation. Finally, we emphasize that the presence of polymers may be a mechanism to delay or to accentuate the appearance of the unbinding transition between fluid membranes.

Effects of polymers on the rotational viscosities of nematic liquid crystals and dynamics of field alignment

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

Kim, D.

Many of the important physical phenomena exhibited by the nematic phase, such as its unusual flow properties and its responses to the electric and the magnetic fields, can be discussed regarding it as a continous medium. The Leslie-Erickson dynamic theory has the six dissipative coefficients from continuum model of liquid crystal. Parodi showed that only five of them are independent, when Onsagar`s reciprocal relations are used. One of these, which has no counterpart in the isotropic liquids, is the rotational viscosity co-efficient, {gamma}{sub 1}. The main objective of this project is to study the rotational viscosities of selected micellar nematicmore » systems and the effect of dissolved polymers in micellar and thermotropic liqud crystals. We used rotating magnetic field method which allows one to determine {gamma}{sub 1} and the anisotropic magnetic susceptibility, {chi}{sub a}. For the ionic surfactant liquid crystals of SDS and KL systems used in this study, the rotational viscosity exhibited an extraordinary drop after reaching the highest values {gamma}{sub 1} as the temperature was lowered. This behavior is not observed in normal liquid crystals. But this phenomena can be attributed to the existence of nematic biaxial phase below the rod-like nematic N{sub c} phase. The pretransitional increase in {gamma}{sub 1} near the disk-like nematic to smectic-A phase transition of the pure CsPFO/H{sub 2}O systems are better understood with the help of mean-field models of W.L. McMillan. He predicted a critical exponent {nu} = {1/2} for the divergence of {gamma}{sub 1}. The polymer (PEO, molecular weight = 10{sup 5}) dissolved in CsPFO/H{sub 2}O system (which has 0.6% critical polymer concentration), suppressed the nematic to lamellar smectic phase transition in concentrated polymer solutions (0.75% and higher). In dilute polymer solutions with lower than 0.3% polyethylene-oxide, a linear increase of {gamma}{sub 1} is observed, which agrees with Brochard theory.« less

Panel Recommends State-Level NAEP for 12th Graders

ERIC Educational Resources Information Center

Olson, Lynn

2004-01-01

A national commission formed to review the future of the 12th grade National Assessment of Educational Progress (NAEP) has recommended that the nation's primary barometer of student performance should expand dramatically to provide mandatory state results on the achievement of 12th graders and to measure their readiness for college, employment,…

Validity of Scores for a Developmental Writing Scale Based on Automated Scoring

ERIC Educational Resources Information Center

Attali, Yigal; Powers, Donald

2009-01-01

A developmental writing scale for timed essay-writing performance was created on the basis of automatically computed indicators of writing fluency, word choice, and conventions of standard written English. In a large-scale data collection effort that involved a national sample of more than 12,000 students from 4th, 6th, 8th, 10th, and 12th grade,…

Multi stage unreliable retrial Queueing system with Bernoulli vacation

NASA Astrophysics Data System (ADS)

Radha, J.; Indhira, K.; Chandrasekaran, V. M.

2017-11-01

In this work we considered the Bernoulli vacation in group arrival retrial queues with unreliable server. Here, a server providing service in k stages. Any arriving group of units finds the server free, one from the group entering the first stage of service and the rest are joining into the orbit. After completion of the i th, (i=1,2,…k) stage of service, the customer may go to (i+1)th stage with probability θi , or leave the system with probability qi = 1 - θi , (i = 1,2,…k - 1) and qi = 1, (i = k). The server may enjoy vacation (orbit is empty or not) with probability v after finishing the service or continuing the service with probability 1-v. After finishing the vacation, the server search for the customer in the orbit with probability θ or remains idle for new arrival with probability 1-θ. We analyzed the system using the method of supplementary variable.

A Record of Uranium-Series Transport in Fractured, Unsaturated Tuff at Nopal I, Sierra Peña Blanca, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Denton, J.; Goldstein, S. J.; Paviet, P.; Nunn, A. J.; Amato, R. S.; Hinrichs, K. A.

2015-12-01

In this study we utilize U-series disequilibria measurements to investigate mineral fluid interactions and the role fractures play in the geochemical evolution of an analogue for a high level nuclear waste repository, the Nopal I uranium ore deposit. Samples of fracture-fill materials have been collected from a vertical drill core and surface fractures. High uranium concentrations in these materials (12-7700 ppm) indicate U mobility and transport from the deposit in the past. U concentrations generally decrease with horizontal distance away from the ore deposit but show no trend with depth. Isotopic activity ratios indicate a complicated geochemical evolution in terms of the timing and extent of actinide mobility, possibly due to changing environmental (redox) conditions over the history of the deposit. 234U/238U activity ratios are generally distinct from secular equilibrium and indicate some degree of open system U behavior during the past 1.2 Ma. However, calculated closed system 238U-234U-230Th model ages are generally >313 ka and >183 ka for the surface fracture and drill core samples respectively, suggesting closed system behavior for U and Th over this most recent time period. Whole rock isochrons drawn for the drill core samples show that at two of three depths fractures have remained closed with respect to U and Th mobility for >200 ka. However, open system behavior for U in the last 350 ka is suggested at 67 m depth. 231Pa/235U activity ratios within error of unity suggest closed system behavior for U and Pa for at least the past 185 ka. 226Ra/230Th activity ratios are typically <1 (0.7-1.2), suggesting recent (<8 ka) radium loss and mobility due to ongoing fluid flow in the fractures. Overall, the mainly closed system behavior of U-Th-Pa over the past ~200 ka provides one indicator of the geochemical immobility of these actinides over long time-scales for potential nuclear waste repositories sited in fractured, unsaturated tuff.

Partition Efficiency of High-Pitch Locular Multilayer Coil for Countercurrent Chromatographic Separation of Proteins Using Small-Scale Cross-Axis Coil Planet Centrifuge and Application to Purification of Various Collagenases with Aqueous-Aqueous Polymer Phase Systems

PubMed Central

Shinomiya, Kazufusa; Kobayashi, Hiroko; Inokuchi, Norio; Nakagomi, Kazuya; Ito, Yoichiro

2010-01-01

Partition efficiency of the high-pitch locular multilayer coil was evaluated in countercurrent chromatographic (CCC) separation of proteins with an aqueous-aqueous polymer phase system using the small-scale cross-axis coil planet centrifuge (X-axis CPC) fabricated in our laboratory. The separation column was specially made by high-pitch (ca 5 cm) winding of 1.0 mm I.D., 2.0 mm O.D. locular tubing compressed at 2 cm intervals with a total capacity of 29.5 mL. The protein separation was performed using a set of stable proteins including cytochrome C, myoglobin, and lysozyme with the 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate system (pH 9.2) under 1000 rpm of column revolution. This high-pitch locular tubing yielded substantially increased stationary phase retention than the normal locular tubing for both lower and upper mobile phases. In order to demonstrate the capability of the high-pitch locular tubing, the purification of collagenase from the crude commercial sample was carried out using an aqueous-aqueous polymer phase system. Using the 16.0% (w/w) PEG 1000 – 6.3% (w/w) dibasic potassium phosphate – 6.3% (w/w) monobasic potassium phosphate system (pH 6.6), collagenase I, II, V and X derived from Clostridium hystolyticum were separated from other proteins and colored small molecular weight compounds present in the crude commercial sample, while collagenase N-2 and S-1 from Streptomyces parvulus subsp. citrinus were eluted with impurities at the solvent front with the upper phase. The collagenase from C. hystolyticum retained its enzymatic activity in the purified fractions. The overall results demonstrated that the high-pitch locular multilayer coil is effectively used for the CCC purification of bioactive compounds without loss of their enzymatic activities. PMID:21869859

77 FR 24705 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-25

..., Corporation. adhesive used polymer with 1,6- for panel hexanediol, [alpha]- lamination and hydro-[omega... used benzenedicarboylic for panel acid, polymer with lamination and 1,4- other assemblies...- isocyanatobenzene]. P-12-0273......... 03/28/2012 06/25/2012 CBI (S) Industrial (S) Coconut oil, coating. polymer...

3-D Particle Simulation of Strongly-Coupled Chains of Charged Polymers

NASA Astrophysics Data System (ADS)

Tanaka, Toyoichi; Tanaka, Motohiko; Pande, V.; Grosberg, A.

1996-11-01

The behaviors of the polyampholyte (PA) which is a connected chain of charged beads (molecules) submerged in the neutral solvent is studied using the 3-D particle simulation code. The major issue is how an equilibrium and kinetics of the PA depend on the thermal and electrostatic forces, i.e., the coupling constant Γ= e^2/aT . We follow a dynamical evolution of the PA, considering the electrostatic force, (2) the binding force between the adjacent beads, (3) the random thermal force exerted by the solvent, and (4) the frictional force: m fracdv_idt = sumj fracZ_iZj e^2 |ri -r_j|^2 hatr_ij - frac3Ta^2(2 ri -r_i+1 -r_i-1) + F^(th) - m ν v_i. Preliminary runs show that, when the excess charge δ N on the chain is larger than N^1/2 ( N : the number of the beads), the size of the polyampholyte increases as in the Monte Carlo simulation using the energy principle [Kantor, Kardar and Li, Phys.Rev.E, 49, 1383 (1994)]. The measured time rate of the size increase for the fixed value of Γ is scaled as, d/dt ~ δ N - N^1/2 for δ N > N^1/2 , and d/dt ~ 0 otherwise.

Antibiotic-containing polymers for localized, sustained drug delivery

PubMed Central

Stebbins, Nicholas D.; Ouimet, Michelle A.; Uhrich, Kathryn E.

2014-01-01

Many currently used antibiotics suffer from issues such as systemic toxicity, short half-life, and increased susceptibility to bacterial resistance. Although most antibiotic classes are administered systemically through oral or intravenous routes, a more efficient delivery system is needed. This review discusses the chemical conjugation of antibiotics to polymers, achieved by forming covalent bonds between antibiotics and a pre-existing polymer or by developing novel antibiotic-containing polymers. Through conjugating antibiotics to polymers, unique polymer properties can be taken advantage of. These polymeric antibiotics display controlled, sustained drug release and vary in antibiotic class type, synthetic method, polymer composition, bond lability, and antibacterial activity. The polymer synthesis, characterization, drug release, and antibacterial activities, if applicable, will be presented to offer a detailed overview of each system. PMID:24751888

pH-sensitive micelles self-assembled from polymer brush (PAE-g-cholesterol)-b-PEG-b-(PAE-g-cholesterol) for anticancer drug delivery and controlled release

PubMed Central

Huang, Xiangxuan; Liao, Wenbo; Zhang, Gang; Kang, Shimin; Zhang, Can Yang

2017-01-01

A novel amphiphilic pH-sensitive triblock polymer brush (poly(β-amino esters)-g-cholesterol)-b-poly(ethylene glycol)-b-(poly(β-amino esters)-g-cholesterol) ((PAE-g-Chol)-b-PEG-b-(PAE-g-Chol)) was designed and synthesized successfully through a three-step reaction, and their self-assembled polymeric micelles were used as hydrophobic anticancer drug delivery carriers to realize effectively controlled release. The critical micelle concentrations were 6.8 μg/mL, 12.6 μg/mL, 17.4 μg/mL, and 26.6 μg/mL at pH values of 7.4, 6.5, 6.0, and 5.0, respectively. The trend of critical micelle concentrations indicated that the polymer had high stability that could prolong the circulation time in the body. The hydrodynamic diameter and zeta potential of the polymeric micelles were influenced significantly by the pH values. As pH decreased from 7.4 to 5.0, the particle size and zeta potential increased from 205.4 nm to 285.7 nm and from +12.7 mV to +47.0 mV, respectively. The pKb of the polymer was confirmed to be approximately 6.5 by the acid–base titration method. The results showed that the polymer had sharp pH-sensitivity because of the protonation of the amino groups, resulting in transformation of the PAE segment from hydrophobic to hydrophilic. Doxorubicin-loaded polymeric micelles were prepared with a high loading content (20%) and entrapment efficiency (60%) using the dialysis method. The in vitro results demonstrated that drug release rate and cumulative release were obviously dependent on pH values. Furthermore, the drug release mechanism was also controlled by the pH values. The polymer had barely any cytotoxicity, whereas the doxorubicin-loaded system showed high toxicity for HepG2 cells as free drugs. All the results proved that the pH-sensitive triblock polymer brush and its self-assembled micelle might be a potential delivery carrier for anticancer drugs with sustained release. PMID:28356738

pH-sensitive micelles self-assembled from polymer brush (PAE-g-cholesterol)-b-PEG-b-(PAE-g-cholesterol) for anticancer drug delivery and controlled release.

PubMed

Huang, Xiangxuan; Liao, Wenbo; Zhang, Gang; Kang, Shimin; Zhang, Can Yang

2017-01-01

A novel amphiphilic pH-sensitive triblock polymer brush (poly(β-amino esters)- g -cholesterol)- b -poly(ethylene glycol)- b -(poly(β-amino esters)- g -cholesterol) ((PAE- g -Chol)- b -PEG- b -(PAE- g -Chol)) was designed and synthesized successfully through a three-step reaction, and their self-assembled polymeric micelles were used as hydrophobic anticancer drug delivery carriers to realize effectively controlled release. The critical micelle concentrations were 6.8 μg/mL, 12.6 μg/mL, 17.4 μg/mL, and 26.6 μg/mL at pH values of 7.4, 6.5, 6.0, and 5.0, respectively. The trend of critical micelle concentrations indicated that the polymer had high stability that could prolong the circulation time in the body. The hydrodynamic diameter and zeta potential of the polymeric micelles were influenced significantly by the pH values. As pH decreased from 7.4 to 5.0, the particle size and zeta potential increased from 205.4 nm to 285.7 nm and from +12.7 mV to +47.0 mV, respectively. The p K b of the polymer was confirmed to be approximately 6.5 by the acid-base titration method. The results showed that the polymer had sharp pH-sensitivity because of the protonation of the amino groups, resulting in transformation of the PAE segment from hydrophobic to hydrophilic. Doxorubicin-loaded polymeric micelles were prepared with a high loading content (20%) and entrapment efficiency (60%) using the dialysis method. The in vitro results demonstrated that drug release rate and cumulative release were obviously dependent on pH values. Furthermore, the drug release mechanism was also controlled by the pH values. The polymer had barely any cytotoxicity, whereas the doxorubicin-loaded system showed high toxicity for HepG2 cells as free drugs. All the results proved that the pH-sensitive triblock polymer brush and its self-assembled micelle might be a potential delivery carrier for anticancer drugs with sustained release.

Photochemical preparation of olefin addition catalysts

NASA Technical Reports Server (NTRS)

Gray, Harry B. (Inventor); Rembaum, Alan (Inventor); Gupta, Amitava (Inventor)

1978-01-01

Novel polymer supported catalysts are prepared by photo-irradiation of low valent transition metal compounds such as Co.sub.2 (CO).sub.8, Rh.sub.4 (CO).sub.12 or Ru.sub.3 (CO).sub.12 in the presence of solid polymers containing amine ligands such as polyvinyl pyridine. Hydroformylation of olefins to aldehydes at ambient conditions has been demonstrated.

Quinoxaline polymers and copolymers derived from 1,4-bis(1'-naphthalenyloxalyl)benzene and their graphite composites. [polymer chemistry and polymer physics

NASA Technical Reports Server (NTRS)

Port, W. S.

1976-01-01

Experimental studies were performed with new polyquinoxalines and their graphite composites. Four polymers were synthesized, and then were characterized with respect to their inherent viscosity, elemental chemical analysis, mechanical, and thermodynamic properties. Structural formulas of the polymers and their precursors are given; methods of synthesis are described; and specifically examined was the preparation of polymers from 3,3' diamino-benzidine from 1,4- and 1,3- bis ((1'-napthalenyl) oxalyl) benzene respectively. Also considered was the preparation of polyquinoxalines from poly (p-benzil), and 1,2- aryldiamines.

Implementation of a SVWP-based laser beam shaping technique for generation of 100-mJ-level picosecond pulses.

PubMed

Adamonis, J; Aleknavičius, A; Michailovas, K; Balickas, S; Petrauskienė, V; Gertus, T; Michailovas, A

2016-10-01

We present implementation of the energy-efficient and flexible laser beam shaping technique in a high-power and high-energy laser amplifier system. The beam shaping is based on a spatially variable wave plate (SVWP) fabricated by femtosecond laser nanostructuring of glass. We reshaped the initially Gaussian beam into a super-Gaussian (SG) of the 12th order with efficiency of about 50%. The 12th order of the SG beam provided the best compromise between large fill factor, low diffraction on the edges of the active media, and moderate intensity distribution modification during free-space propagation. We obtained 150 mJ pulses of 532 nm radiation. High-energy, pulse duration of 85 ps and the nearly flat-top spatial profile of the beam make it ideal for pumping optical parametric chirped pulse amplification systems.

A Study of the Critical Factors Controlling the Synthesis of Ceramic Matrix Composites from Preceramic Polymers.

DTIC Science & Technology

1988-04-15

physical properties of a polycarbosilane preceramic polymer as a function of temperature to derive synthesis methodology for SiC matrix composites , (2...investigate the role of interface modification in creating tough carbon fiber reinforced SiC matrix composites . RESEARCH PROGRESS Preceramic Polymer ...Classfication) A STUDY OF THE CRITICAL FACTORS CONTROLLING THE SYNTHESIS OF CERAMIC MATRIX COMPOSITES FROM PRECERAMIC POLYMERS 12. PERSONAL AUTHOR(S

Ocular Pharmacokinetic Study Using T1 Mapping and Gd-Chelate-Labeled Polymers

PubMed Central

Shi, Xianfeng; Liu, Xin; Wu, Xueming; Lu, Zheng-Rong; Li, S. Kevin

2011-01-01

Purpose Recent advances in drug discovery have led to the development of a number of therapeutic macromolecules for treatment of posterior eye diseases. We aimed to investigate the clearance of macromolecular contrast probes (polymers conjugated with Gd-chelate) in the vitreous after intravitreal injections with the recently developed ms-DSEPI-T12 MRI and to examine the degradation of disulfide-containing biodegradable polymers in the vitreous humor in vivo. Methods Intravitreal injections of model contrast agents poly[N-(2-hydroxypropyl)methacrylamide]-GG-1,6-hexanediamine-(Gd-DO3A), biodegradable (Gd-DTPA)-cystine copolymers, and MultiHance were performed in rabbits; their distribution and elimination from the vitreous after injections were determined by MRI. Results Times for macromolecular contrast agents to decrease to half their initial concentrations in the vitreous ranged from 0.4–1.3 days post-injection. Non-biodegradable polymers demonstrated slower vitreal clearance than those of disulfide-biodegradable polymers. Biodegradable polymers had similar clearance as MultiHance. Conclusions Usefulness of T1 mapping and ms-DSEPI-T12 MRI to study ocular pharmacokinetics was demonstrated. Results suggest an enzymatic degradation mechanism for the disulfide linkage in polymers in the vitreous leading to breakup of polymers in vitreous humor over time. PMID:21691891

Nonlinear optical anisotropy and molecular orientational distribution in poly(p-phenylene benzobisthiazole) Langmuir-Blodgett films

NASA Astrophysics Data System (ADS)

Wang, Liming; Wada, Tatsuo; Yuba, Tomoyuki; Kakimoto, Masaaki; Imai, Yoshio; Sasabe, Hiroyuki

1996-06-01

The orientational distribution and packing of polymer chains were investigated in poly(p-phenylene benzobisthiazole) (PBT) Langmuir-Blodgett (LB) films by nonresonant third-harmonic generation measurement at a wavelength of 1907 nm. The tensor components of the third-harmonic susceptibility on the PBT LB film with a surface pressure of 50 mN/m were determined to be χ(3)XXXX=(16.6±2.5)×10-12 and χ(3)YYYY=(2.0±0.3)×10-12. The large nonlinear optical anisotropy can be explained as a result of highly oriented packing of the polymer chains induced by a flow orientation. A Gaussian distribution function with a standard deviation of σ=0.40 gives a practical description of the orientational distribution of PBT polymer chains. A maximum χ(3) value of (26.8±4.4)×10-12 esu is predicted assuming a perfect alignment of polymer chains. The χ(3)XXXX value increased by factor of 2 with the surface pressure from 30 to 50 mN/m mainly due to the packing density of the polymer chains, while the orientational degree did not change.

UHE particle production in close binary systems

NASA Technical Reports Server (NTRS)

Hillas, A. M.

1985-01-01

Cygnus X-3 appears to generate so much power in the form of charged particles of up to approx 10 to the 17th power eV that the galaxy may need approx 1 such source on average to maintain its flux of ultra high energy cosmic rays. Accreting gas must supply the energy, and in a surprisingly ordered form, if it is correct to use a Vest-rand-Eichler model for radiation of gammas, modified by the introduction of an accretion wake. Certain relationships between 10 to the 12th power eV and 10 to the 15th power gamma rays are expected.

Communication skills and self-esteem in prevention of destructive behaviors.

PubMed

Englander-Golden, P; Jackson, J E; Crane, K; Schwarzkopf, A B; Lyle, P S

1989-01-01

This study demonstrates the long-range effectiveness of SAY IT STRAIGHT training as a school-based program for the prevention of destructive behaviors by comparing juvenile police offenders among trained and untrained 9th-12th graders for 1 1/2 years following training. In the 1984-85 school year, 357 of the 740 9th-12th graders in a southwestern town completed SAY IT STRAIGHT training. Participation was voluntary and required parental permission. During a five-month pretraining period which began with the first day of school, the number of juvenile police offenders was not significantly different among students who would eventually be trained or not be trained. During the following 7 months including summer vacation, there were significantly fewer offenders among the trained students. The following school year and summer vacation there were again significantly fewer offenders among the trained students. During the whole 1 1/2-year study, the untrained students had about 4.5 times as many criminal offenses as the trained students and their offenses were more severe. Finally, 9th, 10th, and 12th graders as well as 11th-grade females who had been trained showed a significant shift toward behavioral intentions reflecting a greater willingness to implement their constructive decisions and feel comfortable doing so. This study extends the applicability of SAY IT STRAIGHT training which previously has been reported to significantly reduce alcohol/drug-related school suspensions among 6th-8th graders.

Hot Melt Extrudates Formulated Using Design Space: One Simple Process for Both Palatability and Dissolution Rate Improvement.

PubMed

Malaquias, Lorena F B; Schulte, Heidi L; Chaker, Juliano A; Karan, Kapish; Durig, Thomas; Marreto, Ricardo N; Gratieri, Tais; Gelfuso, Guilherme M; Cunha-Filho, Marcilio

2018-01-01

This work aimed at obtaining an optimized itraconazole (ITZ) solid oral formulation in terms of palatability and dissolution rate by combining different polymers using hot melt extrusion (HME), according to a simplex centroid mixture design. For this, the polymers Plasdone ® (poly(1-vinylpyrrolidone-co-vinyl acetate) [PVP/VA]), Klucel ® ELF (2-hydroxypropyl ether cellulose [HPC]), and Soluplus ® (SOL, polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol) were processed using a laboratory HME equipment operating without recirculation at constant temperature. Samples were characterized by physicochemical assays, as well as dissolution rate and palatability using an e-tongue. All materials became homogeneous and dense after HME processing. Thermal and structural analyses demonstrated drug amorphization, whereas IR spectroscopy evidenced drug stability and drug-excipient interactions in HME systems. Extrudates presented a significant increase in dissolution rate compared to ITZ raw material, mainly with formulations containing PVP/VA and HPC. A pronounced improvement in taste masking was also identified for HME systems, especially in those containing higher amounts of SOL and HPC. Data showed polymers act synergistically favoring formulation functional properties. Predicted best formulation should contain ITZ 25.0%, SOL 33.2%, HPC 28.9%, and PVP/VA 12.9% (w/w). Optimized response considering dissolution rate and palatability reinforces the benefit of polymer combinations. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Reduced viscosity for flagella moving in a solution of long polymer chains

NASA Astrophysics Data System (ADS)

Zhang, Yuchen; Li, Gaojin; Ardekani, Arezoo M.

2018-02-01

The bacterial flagellum thickness is smaller than the radius of gyration of long polymer chain molecules. The flow velocity gradient over the length of polymer chains can be nonuniform and continuum models of polymeric liquids break in this limit. In this work, we use Brownian dynamics simulations to study a rotating helical flagellum in a polymer solution and overcome this limitation. As the polymer size increases, the viscosity experienced by the flagellum asymptotically reduces to the solvent viscosity. The contribution of polymer molecules to the local viscosity in a solution of long polymer chains decreases with the inverse of polymer size to the power 1/2. The difference in viscosity experienced by the bacterial cell body and flagella can predict the nonmonotonic swimming speed of bacteria in polymer solutions.

Formulation, in vitro evaluation and study of variables on tri-layered gastro-retentive delivery system of diltiazem HCl.

PubMed

Raut Desai, Shilpa; Rohera, Bhagwan D

2014-03-01

Tri-layered floating tablets using only one grade of polyethylene oxide (PEO) would enable easy manufacturing, reproducibility and controlled release for highly soluble drugs. To evaluate the potential of PEO as a sole polymer for the controlled release and to study the effect of formulation variables on release and gastric retention of highly soluble Diltiazem hydrochloride (DTZ). Tablets were compressed with middle layer consisting of drug and polymer while outer layers consisted of polymer with sodium bicarbonate. Design of formulation to obtain 12 h, zero-order release and rapid floatation was done by varying the grades, quantity of PEO and sodium bicarbonate. Dissolution data were fitted in drug release models and swelling/erosion studies were undertaken to verify the drug release mechanism. Effect of formulation variables and tablet surface morphology using scanning electron microscopy were studied. The optimized formula passed the criteria of USP dissolution test I and exhibited floating lag-time of 3-4 min. Drug release was faster from low molecular weight (MW) PEO as compared to high MW. With an increase in the amount of sodium bicarbonate, faster buoyancy was achieved due to the increased CO2 gas formation. Drug release followed zero-order and gave a good fit to the Korsmeyer-Peppas model, which suggested that drug release was due to diffusion through polymer swelling. Zero-order, controlled release profile with the desired buoyancy can be achieved by using optimum formula quantities of sodium bicarbonate and polymer. The tri-layered system shows promising delivery of DTZ, and possibly other water-soluble drugs.

Training effects of wheelchair dance on aerobic fitness in bedridden individuals with severe athetospastic cerebral palsy rated to GMFCS level V.

PubMed

Terada, Kyoko; Satonaka, Ayako; Terada, Yasuto; Suzuki, Nobuharu

2017-10-01

There were few studies about training effects of wheelchair dance on aerobic fitness in the bedridden individuals with severe cerebral palsy for whom the traditional maximal or submaximal exercise tests were not applicable. As the oxygen pulse (O2P), the oxygen uptake divided by the heart rate, is regarded to be a relative measure of stroke volume and the O2P correlates to peak oxygen uptake, we would be able to assess the training effects of wheelchair dance on aerobic fitness in those individuals measuring O2P. To study training effects of wheelchair dance on aerobic fitness in bedridden individuals with severe athetospastic cerebral palsy. Pre-post study design. A laboratory and a community care center. Bedridden individuals with athetospastic cerebral palsy rated to Gross Motor Function Classification System (GMFCS) level V (N.=6). The O2P was compared between during the rest, the waltz, and the jive at the baseline, the 3rd, the 6th, and the 12th month of the intervention of wheelchair dance 6 to 15 minutes at a time, 2 days a week or more. Paired Student's t-test showed that O2P during the waltz and the jive was significantly increased compared with that during the rest at the 6th and the 12th month, and O2P during the jive was also significantly increased compared with that during the rest at the 3rd, the 6th, and the 12th month of the intervention period. This is the first study that shows wheelchair dance may possibly increase aerobic fitness in bedridden individuals with severe athetospastic cerebral palsy rated GMFCS level V. Future studies with a larger sample will be warranted to prove the claim.

Administration of IL-1beta to the 4th ventricle causes anorexia that is blocked by agouti-related peptide and that coincides with activation of tyrosine-hydroxylase neurons in the nucleus of the solitary tract.

PubMed

DeBoer, Mark D; Scarlett, Jarrad M; Levasseur, Peter R; Grant, Wilmon F; Marks, Daniel L

2009-02-01

Inflammation-associated cachexia is associated with multiple chronic diseases and involves activation of appetite regulating centers in the arcuate nucleus of the hypothalamus (ARH). The nucleus of the solitary tract (NTS) in the brainstem has also been implicated as an important nucleus involved in appetite regulation. We set out to determine whether the NTS may be involved in inflammation-associated anorexia by injecting IL-1 beta into the 4th ventricle and assessing food intake and NTS neuronal activation. Injection of IL-1 beta produced a decrease in food intake at 3 and 12h after injection which was ameliorated at the 12h time point by a sub-threshold dose of agouti-related peptide (AgRP). Investigation into neuron types in the NTS revealed that IL-1 beta injection was associated with an increase in c-Fos activity in NTS neurons expressing tyrosine hydroxylase (TH). Additionally, injection of IL-1 beta into the 4th ventricle did not produce c-Fos activation of neurons expressing pro-opiomelanocortin (POMC) in the ARH, cells known to be involved in producing anorexia in response to systemic inflammation. Double-label in situ hybridization revealed that TH neurons did not express IL-1 receptor I (IL1-RI) transcript, demonstrating that c-Fos activation of TH neurons in this setting was not via direct stimulation of IL-1 beta on TH neurons themselves. We conclude that IL-1 beta injection into the 4th ventricle produces anorexia and is accompanied by an increase in activation in TH neurons in the NTS. This provides evidence that the brainstem may be an important mediator of anorexia in the setting of inflammation.

The ASVAB (Armed Services Vocational Aptitude Battery) Score Scales. 1980 and World War II

DTIC Science & Technology

1986-07-01

TABLE B-3 ASVAB 14 (A, B, & C) MECHANICAL & CRAFTS (MC) COMPOSITE PERCENTILE NORMS BY SEX AND GRADE Females Grade Males Total Standard Grade...COMPOSITE PERCENTILE NORMS BY SEX AND GRADE Females Grade Males Total Standard Grade Grade Standard Score 11th 12th nth 12th nth 12th Score 24 24...Standard Scores. B-8 TABLE B-3 ASVAB 14 (A. B,&C) ELECTRONIC & ELECTRICAL (EE) COMPOSITE PERCENTILE NORMS BY SEX AND GRADE Females Grade Males

TH-C-19A-12: Two-Dimensional High Spatial-Resolution Dosimeter Using Europium Doped Potassium Chloride

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

Li, H; Yang, D; Xiao, Z

2014-06-15

Purpose: Recent research has shown that KCl:Eu2+ has great potential for use in megavoltage radiation therapy dosimetry because this material exhibits excellent storage performance and is reusable due to strong radiation hardness. This work reports our attempts to fabricate 2D KCl:Eu2+ storage phosphor films (SPFs) using both a physical vapor deposition (PVD) method and a tape casting method. Methods: A thin layer of KCl:Eu2+ was deposited on a substrate of borosilicate glass (e.g., laboratory slides) with a PVD system. For tape casting, a homogenous suspension containing storage phosphor particles, liquid vehicle and polymer binder was formed and subsequently cast bymore » doctor-blade onto a polyethylene terephthalate substrate to form a 150 μm thick SPF. Results: X ray diffraction analysis showed that a 10 μm thick PVD sample was composed of highly crystalline KCl. No additional phases were observed, suggesting that the europium activator had completed been incorporated into the KCl matrix. Photostimulated luminescence and photoluminescence spectra suggested that F (Cl−) centers were the electron storage centers post x ray irradiation and that Eu2+ cations acted as luminescence centers in the photostimulation process. The 150 μm thick casted KCl:Eu2+ SPF showed sub-millimeter spatial resolution. Monte Carlo simulations further demonstrated that the admixture of 20% KCl:Eu2+ and 80% low Z polymer binder exhibited almost no energy dependence in a 6 MV beam. KCl:Eu2+ pellet samples showed a large dynamic range from 0.01 cGy to 60 Gy dose-to-water, and saturated at approximately 500 Gy as a Result of its intrinsic high radiation hardness. Conclusions: This discovery research provides strong evidence that KCl:Eu2+ based SPF with associated readout apparatus could Result in a novel electronic film system that has all the desirable features associated with classic radiographic film and, importantly, water equivalence and the capability of permanent identification of each detector. This work was supported in part by NIH Grant No. R01CA148853. The authors would like to thank Paul Leblans (AGFA Healthcare, Belgium) for many helpful discussions on this topic.« less

Passive control of quorum sensing: prevention of Pseudomonas aeruginosa biofilm formation by imprinted polymers.

PubMed

Piletska, Elena V; Stavroulakis, Georgios; Larcombe, Lee D; Whitcombe, Michael J; Sharma, Anant; Primrose, Sandy; Robinson, Gary K; Piletsky, Sergey A

2011-04-11

Here we present the first molecular imprinted polymer (MIP) that is able to attenuate the biofilm formation of the opportunistic human pathogen Pseudomonas aeruginosa through specific sequestration of its signal molecule N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C(12)-AHL). The MIP was rationally designed using computational modeling, and its capacity and specificity and that of a corresponding blank polymer toward signal molecule of P. aeruginosa (3-oxo-C(12)-AHL) and its analogue were tested. The biofilm formation in the presence of polymers and without polymers was studied using scanning confocal laser microscopy. Staining with crystal violet dye was used for the quantification of the biofilm formation. A significant reduction of the biofilm growth was observed in the presence of MIP (>80%), which was superior to that of the resin prepared without template, which showed a reduction of 40% in comparison with biofilm, which was grown without polymer addition. It was shown that 3-oxo-C(12)-AHL-specific MIP prevented the development of quorum-sensing-controlled phenotypes (in this case, biofilm formation) from being up-regulated. The developed MIP could be considered as a new tool for the elimination of life-threatening infections in a multitude of practical applications; it could, for example, be grafted on the surface of medical devices such as catheters and lenses, be a component of paints, or be used as a wound adsorbent.

12 CFR 271.4 - Records available for public inspection and copying.

Code of Federal Regulations, 2012 CFR

2012-01-01

... copying. 271.4 Section 271.4 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) FEDERAL OPEN MARKET.... weekdays, at the Freedom of Information Office of the Board of Governors of the Federal Reserve System, 20th Street and Constitution Avenue, N.W., Washington, D.C. 20551 (the pedestrian entrance is on C...

12 CFR 271.4 - Records available for public inspection and copying.

Code of Federal Regulations, 2010 CFR

2010-01-01

... copying. 271.4 Section 271.4 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) FEDERAL OPEN MARKET.... weekdays, at the Freedom of Information Office of the Board of Governors of the Federal Reserve System, 20th Street and Constitution Avenue, N.W., Washington, D.C. 20551 (the pedestrian entrance is on C...

12 CFR 271.4 - Records available for public inspection and copying.

Code of Federal Regulations, 2014 CFR

2014-01-01

... copying. 271.4 Section 271.4 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) FEDERAL OPEN MARKET.... weekdays, at the Freedom of Information Office of the Board of Governors of the Federal Reserve System, 20th Street and Constitution Avenue, N.W., Washington, D.C. 20551 (the pedestrian entrance is on C...

A Michigan School Money Primer for Policymakers, School Officials, Media and Residents

ERIC Educational Resources Information Center

Olson, Ryan S.; LaFaive, Michael D.

2007-01-01

The system that finances Michigan's schools from kindergarten through 12th grade is a perennial topic of conversation among policymakers, parents, taxpayers and voters. A constructive discussion of this issue, however, requires a sound knowledge of the financial workings of Michigan's elementary and secondary school system. This knowledge is…

Using the SSIS Assessments with Australian Students: A Comparative Analysis of Test Psychometrics to the US Normative Sample

ERIC Educational Resources Information Center

Sherbow, Amanda; Kettler, Ryan J.; Elliott, Stephen N.; Davies, Michael; Dembitzer, Leah

2015-01-01

The Social Skills Improvement System (SSIS; Gresham & Elliott, 2008) is a multiple stage, broadband system for assessing and intervening with children in preschool through 12th grade originally normed in the USA. Two of the assessment components of this system were analysed: (a) the Performance Screening Guides (PSGs); and (b) the Rating…

Design Document for 12th Grade NAEP Preparedness Research Judgmental Standard Setting Studies: Setting Standards on the National Assessment of Educational Progress in Reading and Mathematics for 12th Grade Preparedness

ERIC Educational Resources Information Center

National Assessment Governing Board, 2010

2010-01-01

The National Assessment Governing Board adopted a Program of Preparedness Research in March 2009. Several categories of research studies were recommended to produce results for reporting 12th grade preparedness for the 2009 grade 12 National Assessment of Educational Progress (NAEP) in reading and mathematics. The categories included content…

EDITORIAL: Artificial Muscles: Selected papers from the 5th World Congress on Biomimetics, Artificial Muscles and Nano-Bio (Osaka, Japan, 25-27 November 2009) Artificial Muscles: Selected papers from the 5th World Congress on Biomimetics, Artificial Muscles and Nano-Bio (Osaka, Japan, 25-27 November 2009)

NASA Astrophysics Data System (ADS)

Shahinpoor, Mohsen

2011-12-01

The 5th World Congress on Biomimetics, Artificial Muscles and Nano-Bio and the 4th International Conference on Artificial Muscles were held in Osaka, Japan, 23-27 November 2009. This special section of Smart Materials and Structures is devoted to a selected number of research papers presented at this international conference and congress. Of the 76 or so papers presented at the conference, only 10 papers were finally selected, reviewed and accepted for this special section, following the regular reviewing procedures of the journal. This special section is focused on polymeric artificial muscles, electroactive polymers, multifunctional nanocomposites and their applications. In particular, an electromechanical model for self-sensing ionic polymer-metal composite actuating devices with patterned surface electrodes is presented which discusses the concept of creating self-sensing ionic polymer-metal composite (IPMC) actuating devices with patterned surface electrodes where actuator and sensor elements are separated by a grounded shielding electrode. Eventually, an electromechanical model of the device is also proposed and validated. Following that, there is broad coverage of polytetrahydrofurane-polyethylene oxide-PEDOT conducting interpenetrating polymer networks (IPNs) for high speed actuators. The conducting polymer (poly(3,4-ethylenedioxythiophene)) is incorporated within the IPNs, which are synthesized from polyethylene oxide (PEO)/polytetrahydrofurane (PTHF) networks. PEO/PTHF IPNs are prepared using poly(ethylene glycol) methacrylate and dimethacrylate and hydroxythelechelic PTHF as starting materials. The conducting IPN actuators are prepared by oxidative polymerization of 3,4-ethylenedioxithiophene (EDOT) using FeCl3 as an oxidizing agent within the PEO/PTHF IPN host matrix. Subsequently, giant and reversible magnetorheology of carrageenan/iron oxide magnetic gels are discussed and the effect of magnetic fields on the viscoelastic properties, magnetorheological effect of carrageenan gel containing iron oxide particles are investigated using dynamic viscoelastic measurements under magnetic fields. Furthermore, the relationship between the magnetorheology and the elasticity of magnetic gel is discussed. This special section then covers the characteristics of ionic polymer-metal composite with chemically-doped TiO2 particles to improve the bending performance of ionic polymer-metal composite (IPMC) actuators. This study is mainly focused on the characterization of the physical, electrochemical, and electromechanical properties of TiO2-doped ionic polymer membranes, and IPMCs prepared by the sol-gel method, which results in a uniform distribution of the particles inside the polymer membrane. It was determined that the lifetime of IPMC is strongly dependent on the level of water uptake. This paper is then followed by a presentation on training and shape retention in conducting polymer artificial muscles. Electrochemomechanical deformation (ECMD) of the conducting polymer, polyaniline film, is studied to investigate the behavior of actuation under tensile loads. The ECMD is induced by strains due to insertion of ionic species (cyclic strain) and a creep due to applied loads during the redox cycle. The cyclic strain is enhanced by the experience of high tensile loads, indicating a training effect. The training effect is explained by the enhanced electrochemical activity of the film. The special section then presents a paper on the current status and future prospects of power generators using dielectric elastomers. Electroactive polymer artificial muscle (EPAM), known as 'dielectric elastomer', appears to offer unique capabilities as an actuator and electrical power generator. However, the power output levels of such generators are small and the efficiencies are rather high. For example, electrical energy conversion efficiency of over 70% has been achieved. The ability of EPAM to produce hydrogen fuel for energy storage was also demonstrated. Because the energy conversion principle of EPAM is capacitive in nature, the performance is largely size-independent. Formation of motile assembly of microtubules driven by kinesins is presented next. Microtubule (MT) and kinesin are rail and motor proteins that are involved in various moving events of eukaryotic cells in natural systems. In vitro, the sliding motion of microtubules (rail) can be reproduced on a kinesin (motor protein)-coated surface coupled with adenosine triphosphate (ATP) hydrolysis, which is called a 'motility assay'. Based on this technique, a method is reported for forming MT assemblies by an active self-assembly (AcSA) process, in which MTs are crosslinked during a sliding motion on a kinesin-coated surface. Streptavidin (ST) is employed as glue to crosslink biotin-labeled MTs. This discussion is then followed by a paper on the performances of fast-moving low-voltage electromechanical actuators based on single-walled carbon nanotubes and ionic liquids. Here the mechanical and electrical properties of the polymer-free single-walled carbon nanotube (SWNT) sheets containing different contents of ionic liquids (ILs) are reported. The polymer-free SWNT sheets are prepared with the knowledge that millimeter-long 'super growth' carbon nanotubes (SG-SWNTs), produced by a water-assisted modified CVD method, associate together tightly with ILs. The molecular mechanism of electroactive polymer actuators is then discussed in the next paper. Movement of ionic electroactive polymer actuators utilizes their anisotropic volume change, which is induced by the applied voltage. The mechanism of the volume change is, however, not well understood, especially at the molecular level. The current understanding of the mechanism of the volume change at the molecular level is reviewed, focusing on the actuators made with carbon materials. Then, the pressure generated in the actuators in response to the applied voltage based on the results of the Monte Carlo simulation is discussed. It is shown that the mechanism of the actuators can be analyzed at the molecular level in terms of the balance between the electrostatic and volume exclusion interactions that act among the electrode materials and the electrolyte ions. The special section then presents a master curve for analyzing the electrochemical aging and memory effects of poly(3,4-ethylenedioxythiophene). The memory effect of conducting polymers in an electrochemical environment is investigated. This memory effect is related to the electromechanical responses of the conducting polymer. Poly(3,4-ethylenedioxythiophene) is chosen because of its interesting properties—mainly its chemical and electrochemical stabilities. By means of cyclic voltammetry, the influence of the waiting time tw at a holding potential Ew in relation to the conformational relaxation process occurring in the conducting polymer is analyzed. The effect of electrochemical aging on the electrical properties is also explained from the viewpoint of the rearrangement of polymer chains. This completes a brief report on the content of the special section on artificial muscles. I would like to thank the contributing authors of this collection of papers on artificial muscles for their outstanding and unique contributions. I am also indebted to all of the reviewers, editors and editorial staff who handled the reviews of all the papers for their time and effort. I would like to express my sincere thanks and appreciation to Professor E Garcia, Editor-in-Chief, for his encouragement and support, and for providing the opportunity to publish this special section of Smart Materials and Structures. I am also grateful to the IOP Publishing team for their support. In particular, I am greatly indebted to publisher Natasha Leeper, for her help and excellent management in the preparation of this special section on artificial muscles.

A polymer driveshaft for use in orbital and rotational atherectomy

NASA Astrophysics Data System (ADS)

Grothe, Preston Lee

Driveshafts used in atherectomy medical devices are often comprised of coiled or braided metal wires. These constructions are designed to tolerate delivery through tortuous vessels and can endure high speed rotation used during activation of the atherectomy treatment. This research investigated polymer driveshaft designs, which were comprised of polymer inner and outer layers, and coiled or braided stainless steel wires. The polymer driveshaft materials included polyimide, nylon 12, and polytetrafluoroethylene (PTFE). Mechanical testing of polymer driveshafts was conducted to determine material response in bending, tension, compression, and torsion. The polymer driveshaft test results were then compared with current coiled metal wire driveshaft constructions. The investigation identified polymer driveshaft options that could feasibly work in an atherectomy application.

76 FR 32188 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-03

...,11,14- additive. heptaphenyl. P-11-0096 12/08/10 03/07/11 AOC LLC (S) Polymer (S) 1,4- component for benzenedicarboxy laminating of lic acid, 1,4- fiberglass dimethyl ester, reinforced polymer with 1,4- plastic parts... products with ethylene glycol, polymers with 1,4- cyclohexanedimet hanol, diethylene glycol, ethylene...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2011 CFR

2011-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2012 CFR

2012-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2014 CFR

2014-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2013 CFR

2013-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

Processing of Thermotropic Liquid Crystalline Polymers and Their Blends

DTIC Science & Technology

1990-02-23

Dziemianowicz, J. Romanski and W. Werber , Polym. Eng. Sci., 28(12), 785 (1988). 22. C. U. Ko and G. L. Wilkes, J. Appi. Polym. Sci., 37, 3063 (1989). 23. K...Virginia 22217-5000 NSTL, Mississippi 39529 Dr. Bernard Dauda 1 Naval Weapons Center Naval Weapons Support Center Attn: Dr. Ron Atkins Code UKC Chemistry

Relationships between Grade Levels, Personal Factors, and Instructional Variation among 4th-12th Grade Teachers

ERIC Educational Resources Information Center

White, Jacquelyn M.

2011-01-01

The purpose of this quantitative correlational study was to investigate relationships between grade levels, personal factors of teachers, and instructional variety used by 4th-12th grade teachers in Kern County, California. The population under investigation included 2,844 teachers. 235 elementary, middle school/junior high, and secondary teachers…

RADIATION MALFORMATIONS BELONGING TO THE CYCLOPIA-ARRHINENCEPHALIA- OTECEPHALIA GROUP IN THE MOUSE FETUS

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

Marakami, U.; Kameyana, Y.; Majima, A.

1962-03-01

Pregnant mice on the 8.5th day of gestation were subjected to 200-r whole-body irradiation and the fetuses were examined on the l3th to l9th day of gestation. Incidence of fetal death (23.0%) was much higher than in the controls (8.2%1, and malformations of the nose, eyes, and ears cecurred in 32%. These malformations included alterations leading to a beaklike snout (19%), a univentricular telencephalon with cyclopia (6%), and forms transitional between these two (6%). These malformations were specific for irradiation on the 8.5th day of gestation; in previous studies they were not prominent when irradiation was carried out on themore » 8th, lOth, or llth day. During this most sensitive developmental stsge at 8.5 days, 3 to 5 brain vesicles are formed and the anterior neuropore is closed, which may account for the greater effect of teratogenic agents on the central nervous system at this time. Other abnormalities included exencephalia 12%), hydrocephalus (4%), microcephalia 10.7%), abnormally shaped head (5%), spinal cord anomalies (6%), eye anomalies (29%1, harelip and cleft palate (12%), tail abnormalities (6%), and thoraco- abdominal hernia (5%). (H.H.D.)« less

Numerical simulation of a lattice polymer model at its integrable point

NASA Astrophysics Data System (ADS)

Bedini, A.; Owczarek, A. L.; Prellberg, T.

2013-07-01

We revisit an integrable lattice model of polymer collapse using numerical simulations. This model was first studied by Blöte and Nienhuis (1989 J. Phys. A: Math. Gen. 22 1415) and it describes polymers with some attraction, providing thus a model for the polymer collapse transition. At a particular set of Boltzmann weights the model is integrable and the exponents ν = 12/23 ≈ 0.522 and γ = 53/46 ≈ 1.152 have been computed via identification of the scaling dimensions xt = 1/12 and xh = -5/48. We directly investigate the polymer scaling exponents via Monte Carlo simulations using the pruned-enriched Rosenbluth method algorithm. By simulating this polymer model for walks up to length 4096 we find ν = 0.576(6) and γ = 1.045(5), which are clearly different from the predicted values. Our estimate for the exponent ν is compatible with the known θ-point value of 4/7 and in agreement with very recent numerical evaluation by Foster and Pinettes (2012 J. Phys. A: Math. Theor. 45 505003).

Hematite (U-Th)/He thermochronometry constrains intraplate strike-slip faulting on the Kuh-e-Faghan Fault, central Iran

NASA Astrophysics Data System (ADS)

Calzolari, Gabriele; Rossetti, Federico; Ault, Alexis K.; Lucci, Federico; Olivetti, Valerio; Nozaem, Reza

2018-03-01

The Kuh-e-Faghan strike-slip fault system (KFF), located to the northern edge of the Lut Block in central Iran, developed through a Neogene-Quaternary pulsed history of eastward fault propagation and fault-related exhumation. This system is a consequence of the residual stresses transmitted from the Arabia-Eurasia convergent plate boundary. Here we integrate structural and textural analysis with new and previously published apatite fission-track (AFT) and apatite (U-Th)/He (apatite He) results, chlorite thermomentry, and hematite (U-Th)/He data from hematite-coated brittle fault surfaces to constrain the timing of tectonic activity and refine patterns of late Miocene-Pliocene burial and exhumation associated with the propagation of the KFF. Twenty-nine hematite (U-Th)/He (hematite He) dates from three striated hematite coated slip surfaces from the KFF fault core and damage zone yield individual dates from 12-2 Ma. Petrographic analysis and chlorite thermometry of a polyphase, fossil fluid system in the KFF fault core document that fluid circulation and mineralization transitioned from a closed system characterized by pressure solution and calcite growth to an open system characterized by hot hydrothermal (T = 239 ± 10 °C) fluids and hematite formation. Hematite microtextures and grain size analysis reveal primary and secondary syntectonic hematite fabrics, no evidence of hematite comminution and similar hematite He closure temperatures ( 60-85 °C) in each sample. Integration of these results with thermal history modeling of AFT and apatite He data shows that KFF activity in the late Miocene is characterized by an early stage of fault nucleation, fluid circulation, hematite mineralization, and eastward propagation not associated with vertical movement that lasted from 12 to 7 Ma. Hematite He, AFT, and apatite He data track a second phase of fault system activity involving fault-related exhumation initiating at 7 Ma and continuing until present time. Our new data constrain the onset of the recognized Late Miocene-Pliocene tectonic reorganization in north-central Iran.

A Brief Study on Toxic Combustion Products of the Polymers Used in High-Pressure Oxygen Systems

NASA Technical Reports Server (NTRS)

Hshieh, Fu-Yu; Beeson, Harold D.

2005-01-01

One likely cause of polymer ignition in a high-pressure oxygen system is the adiabatic-compression heating of polymers caused by pneumatic impact. Oxidative pyrolysis or combustion of polymers in a high-pressure oxygen system could generate toxic gases. This paper investigates the feasibility of using the NASA pneumatic-impact system to conduct adiabatic-compression combustion tests and determines the toxic combustion products produced from the burning of five selected polymers. Five polymers commonly used in high-pressure oxygen systems, Zytel(Registered TradeMark) 42 (Nylon 6/6), Buna N (nitrile rubber), Witon(Registered TradeMark) A (copolymer of vinylidene fluoride and hexafluoropropylene), Neoflon(Registered TradeMark) (polychlorotrifluoroethylene), and Teflon(Registered TradeMark) (polytetrafluoroethylene), were tested in the NASA pneumatic-impact test system at 17.2-MPa oxygen pressure. The polymers were ignited and burned; combustion products were collected in a stainless-steel sample bottle and analyzed using various methods. The results show that the NASA pneumatic-impact system is an appropriate test system to conduct adiabatic-compression combustion tests and to collect combustion products for further chemical analysis. The composition of the combustion product gas generated from burning the five selected polymers are presented and discussed.

Microwave promoted simple, efficient and regioselective synthesis of trisubstituted imidazo[1,2-a]benzimidazoles on soluble support.

PubMed

Chen, Li-Hsun; Hsiao, Ya-Shan; Yellol, Gorakh S; Sun, Chung-Ming

2011-03-14

An efficient microwave-assisted and soluble polymer-supported synthesis of medicinally important imidazole-fused benzimidazoles has been developed. The protocol involves the rapid condensation of polymer-bound amino benzimidazoles with various α-bromoketones and subsequent in situ intramolecular cyclization under microwave irradiation resulting in a one pot synthesis of imidazole interlacing benzimidazole polymer conjugates. The condensed product was obtained with excellent regioselectivity. The biologically interesting imidazo[1,2-a]benzimidazoles was released from polymer support at ambient temperature. Diversity in the triheterocyclic nucleus was achieved by the different substitutions at its 2, 3, and 9 positions. The new protocol has the advantages of short reaction time, easy workup process, excellent yields, reduced environmental impact, wide substrate scope and convenient procedure.

Stability effect of cholesterol-poly(acrylic acid) in a stimuli-responsive polymer-liposome complex obtained from soybean lecithin for controlled drug delivery.

PubMed

Simões, M G; Alves, P; Carvalheiro, Manuela; Simões, P N

2017-04-01

The development of polymer-liposome complexes (PLCs), in particular for biomedical applications, has grown significantly in the last decades. The importance of these studies comes from the emerging need in finding intelligent controlled release systems, more predictable, effective and selective, for applications in several areas, such as treatment and/or diagnosis of cancer, neurological, dermatological, ophthalmic and orthopedic diseases, gene therapy, cosmetic treatments, and food engineering. This work reports the development and characterization of a pH sensitive system for controlled release based on PLCs. The selected hydrophilic polymer was poly(acrylic acid) (PAA) synthesized by atom transfer radical polymerization (ATRP) with a cholesterol (CHO) end-group to improve the anchoring of the polymer into the lipid bilayer. The polymer was incorporated into liposomes formulated from soybean lecithin and stearylamine, with different stearylamine/phospholipid and polymer/phospholipid ratios (5, 10 and 20%). The developed PLCs were characterized in terms of particle size, polydispersity, zeta potential, release profiles, and encapsulation efficiency. Cell viability studies were performed to assess the cytotoxic potential of PLCs. The results showed that the liposomal formulation with 5% of stearylamine and 10% of polymer positively contribute to the stabilization of the complexes. Afterwards, the carboxylic acid groups of the polymer present at the surface of the liposomes were crosslinked and the same parameters analyzed. The crosslinked complexes showed to be more stable at physiologic conditions. In addition, the release profiles at different pHs (2-12) revealed that the obtained complexes released all their content at acidic conditions. In summary, the main accomplishments of this work are: (i) innovative synthesis of cholesterol-poly(acrylic acid) (CHO-PAA) by ATRP; (ii) stabilization of the liposomal formulation by incorporation of stearylamine and CHO-PAA; (iii) new approach for CHO-PAA crosslinking, resulting in more stable PLCs at physiological conditions; (iv) destabilization of PLCs upon slight changes of pH, showing their pH sensitivity; and (v) the PLCs do not exhibit cellular toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Macromolecular 'size' and 'hardness' drives structure in solvent-swollen blends of linear, cyclic, and star polymers.

PubMed

Gartner, Thomas E; Jayaraman, Arthi

2018-01-17

In this paper, we apply molecular simulation and liquid state theory to uncover the structure and thermodynamics of homopolymer blends of the same chemistry and varying chain architecture in the presence of explicit solvent species. We use hybrid Monte Carlo (MC)/molecular dynamics (MD) simulations in the Gibbs ensemble to study the swelling of ∼12 000 g mol -1 linear, cyclic, and 4-arm star polystyrene chains in toluene. Our simulations show that the macroscopic swelling response is indistinguishable between the various architectures and matches published experimental data for the solvent annealing of linear polystyrene by toluene vapor. We then use standard MD simulations in the NPT ensemble along with polymer reference interaction site model (PRISM) theory to calculate effective polymer-solvent and polymer-polymer Flory-Huggins interaction parameters (χ eff ) in these systems. As seen in the macroscopic swelling results, there are no significant differences in the polymer-solvent and polymer-polymer χ eff between the various architectures. Despite similar macroscopic swelling and effective interaction parameters between various architectures, the pair correlation function between chain centers-of-mass indicates stronger correlations between cyclic or star chains in the linear-cyclic blends and linear-star blends, compared to linear chain-linear chain correlations. Furthermore, we note striking similarities in the chain-level correlations and the radius of gyration of cyclic and 4-arm star architectures of identical molecular weight. Our results indicate that the cyclic and star chains are 'smaller' and 'harder' than their linear counterparts, and through comparison with MD simulations of blends of soft spheres with varying hardness and size we suggest that these macromolecular characteristics are the source of the stronger cyclic-cyclic and star-star correlations.

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

McLeod, John A., E-mail: jmcleod@suda.edu.cn; Pitman, Amy L.; Moewes, Alexander

The electronic structure of [6,6]-phenyl C{sub 61} butyric acid methyl ester (PCBM), poly(3-hexylthiophene) (P3HT), and P3HT/PCBM blends is studied using soft X-ray emission and absorption spectroscopy and density functional theory calculations. We find that annealing reduces the HOMO-LUMO gap of P3HT and P3HT/PCBM blends, whereas annealing has little effect on the HOMO-LUMO gap of PCBM. We propose a model connecting torsional disorder in a P3HT polymer to the HOMO-LUMO gap, which suggests that annealing helps to decrease the torsional disorder in the P3HT polymers. Our model is used to predict the characteristic length scales of the flat P3TH polymer segmentsmore » in P3HT and P3HT/PCBM blends before and after annealing. Our approach may prove useful in characterizing organic photovoltaic devices in situ or even in operando.« less

78 FR 8987 - Standards To Prevent, Detect, and Respond to Sexual Abuse and Assault in Confinement Facilities...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-07

...; Potomac Center North, 500 12th Street SW., Washington, DC 20536; Contact Telephone Number (202) 732-4292... Homeland Security; Potomac Center North, 500 12th Street SW., Washington, DC 20536; Telephone: (202) 732... Security; Potomac Center North, 500 12th Street SW., Washington, DC 20536; Telephone: (202) 732-4292 (not a...

Design and implementation of an experiment scheduling system for the ACTS satellite

NASA Technical Reports Server (NTRS)

Ringer, Mark J.

1994-01-01

The Advanced Communication Technology Satellite (ACTS) was launched on the 12th of September 1993 aboard STS-51. All events since that time have proceeded as planned with user operations commencing on December 6th, 1993. ACTS is a geosynchronous satellite designed to extend the state of the art in communication satellite design and is available to experimenters on a 'time/bandwidth available' basis. The ACTS satellite requires the advance scheduling of experimental activities based upon a complex set of resource, state, and activity constraints in order to ensure smooth operations. This paper describes the software system developed to schedule experiments for ACTS.

Experimental comparison of photogrammetry for additive manufactured parts with and without laser speckle projection

NASA Astrophysics Data System (ADS)

Sims-Waterhouse, D.; Bointon, P.; Piano, S.; Leach, R. K.

2017-06-01

In this paper we show that, by using a photogrammetry system with and without laser speckle, a large range of additive manufacturing (AM) parts with different geometries, materials and post-processing textures can be measured to high accuracy. AM test artefacts have been produced in three materials: polymer powder bed fusion (nylon-12), metal powder bed fusion (Ti-6Al-4V) and polymer material extrusion (ABS plastic). Each test artefact was then measured with the photogrammetry system in both normal and laser speckle projection modes and the resulting point clouds compared with the artefact CAD model. The results show that laser speckle projection can result in a reduction of the point cloud standard deviation from the CAD data of up to 101 μm. A complex relationship with surface texture, artefact geometry and the laser speckle projection is also observed and discussed.

Performance characterization of an abiotic and fluorescent-based continuous glucose monitoring system in patients with type 1 diabetes.

PubMed

Mortellaro, Mark; DeHennis, Andrew

2014-11-15

A continuous glucose monitoring (CGM) system consisting of a wireless, subcutaneously implantable glucose sensor and a body-worn transmitter is described and clinical performance over a 28 day implant period in 12 type 1 diabetic patients is reported. The implantable sensor is constructed of a fluorescent, boronic-acid based glucose indicating polymer coated onto a miniaturized, polymer-encased optical detection system. The external transmitter wirelessly communicates with and powers the sensor and contains Bluetooth capability for interfacing with a Smartphone application. The accuracy of 19 implanted sensors were evaluated over 28 days during 6 in-clinic sessions by comparing the CGM glucose values to venous blood glucose measurements taken every 15 min. Mean absolute relative difference (MARD) for all sensors was 11.6 ± 0.7%, and Clarke error grid analysis showed that 99% of paired data points were in the combined A and B zones. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Enhancement of the Th1-phenotype immune system by the intake of Oyster mushroom (Tamogitake) extract in a double-blind, placebo-controlled study.

PubMed

Tanaka, Aiko; Nishimura, Mie; Sato, Yuji; Sato, Hiroki; Nishihira, Jun

2016-10-01

Pleurotus cornucopiae (Oyster mushroom, Tamogitake) has long been eaten as a functional food for enhancement of the immune system, but its effectiveness has not been well confirmed in humans. To this end, we set up a double-blind placebo-controlled human clinical trial to investigate the potential of Oyster mushrooms with respect to the up-regulation of the immune system. The subjects ingested Oyster mushroom extract for 8 weeks. We measured the serum cytokine levels involved in regulation of the immune system, including interferon (IFN)-γ, interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, and tumor-necrosis factor (TNF)-α. We found that intake of Oyster mushroom extract elevated IFN-γ ( P  = 0.013) and IL-12, whereas serum levels of IL-10 and IL-13 and other cytokines were minimally changed. We also measured natural killer (NK) cell activity, the levels of which tended to increase, but not significantly. Taken together, these facts suggest that Oyster mushrooms have the potential to enhance the immune system, through Th1 phenotype potentiation as the macrophage-IL-12 - IFN-γ pathway. This results in activation of the cell-mediated immune system as exemplified by up-regulation of NK cell activity. Oyster mushroom extract may be beneficial for the prevention of various diseases, including infectious diseases and cancer, due to its stimulation of the immune system.

Porous polymer media

DOEpatents

Shepodd, Timothy J.

2002-01-01

Highly crosslinked monolithic porous polymer materials for chromatographic applications. By using solvent compositions that provide not only for polymerization of acrylate monomers in such a fashion that a porous polymer network is formed prior to phase separation but also for exchanging the polymerization solvent for a running buffer using electroosmotic flow, the need for high pressure purging is eliminated. The polymer materials have been shown to be an effective capillary electrochromatographic separations medium at lower field strengths than conventional polymer media. Further, because of their highly crosslinked nature these polymer materials are structurally stable in a wide range of organic and aqueous solvents and over a pH range of 2-12.

Optical fiber sensor for the detection of laser-generated ultrasound in arterial tissues

NASA Astrophysics Data System (ADS)

Beard, Paul C.; Mills, Timothy N.

1995-02-01

Theoretical and experimental aspects of an extrinsic Fabry-Perot optical fiber ultrasound sensor for use in a photoacoustic-guided laser angioplasty system are described. The sensor has been characterized using laser generated thermoelastic waves as a source of wideband ultrasound. A system sensitivity of 25 mV/MPa and an acoustic noise floor of 2 Pa/Hz1/2 are reported using a transparent polymer film as the sensing element. The system demonstrates the required bandwidth for sensing thermoelastic waves containing frequency components up to 20 MHz.

Homoleptic ligands vs heteroleptic ligands on coordination polymerizations: Construction and properties of silver(I) coordination polymers containing dialkylbis(4-pyridy)silanes

NASA Astrophysics Data System (ADS)

Park, Minwoo; Jang, Jaeseong; Moon, So Yun; Jung, Ok-Sang

2014-03-01

Investigations into pure bidentate ligand vs mixed bidentate ligands on self-assembly of AgPF6 with the respective L1, L2, L3, L1/L2, L1/L3, and L2/L3 (L1 = diethylbis(4-pyridyl)silane; L2 = ethylmethylbis(4-pyridyl)silane; L3 = cyclotetramethylenebis(4-pyridyl)silane) were carried out. The self-assembly reactions of AgPF6 with the respective ligand system produce desirable homoleptic or heteroleptic silver(I) coordination polymers. [Ag(L1)2](PF6) gives rise to a tubular loop chain whereas the other five products lead to a twofold interpenetration diamonoid structure. [Ag(L1)2](PF6) shows a strong blue luminescence at 453 nm (λex = 270 nm), which is useful to recognize alcohols. All products were characterized by thermal analyses, and in particular, calcination of [Ag(L3)2](PF6)ṡCH3OH at 600 °C finally produces silver(0) microcrystalline morphology.

Biocatalytic route to sugar-PEG-based polymers for drug delivery applications.

PubMed

Bhatia, Sumati; Mohr, Andreas; Mathur, Divya; Parmar, Virinder S; Haag, Rainer; Prasad, Ashok K

2011-10-10

Sugar-PEG-based polymers were synthesized by enzymatic copolymerization of 4-C-hydroxymethyl-1,2-O-isopropylidene-β-L-threo-pentofuranose/4-C-hydroxymethyl-1,2-O-benzylidene-β-L-threo-pentofuranose/4-C-hydroxymethyl-1,2-O-isopropylidene-3-O-pentyl-β-L-threo-pentofuranose with PEG-600 dimethyl ester using Novozyme-435 (Candida antarctica lipase immobilized on polyacrylate). Carbohydrate monomers were obtained by the multistep synthesis starting from diacetone-D-glucose and PEG-600 dimethyl ester, which was in turn obtained by the esterification of the commercially available PEG-600 diacid. Aggregation studies on the copolymers revealed that in aqueous solution those polymers bearing the hydrophobic pentyl/benzylidene moiety spontaneously self-assembled into supramolecular aggregates. The critical aggregation concentration (CAC) of polymers was determined by surface tension measurements, and the precise size of the aggregates was obtained by dynamic light scattering. The polymeric aggregates were further explored for their drug encapsulation properties in buffered aqueous solution of pH 7.4 (37 °C) using nile red as a hydrophobic model compound by means of UV/vis and fluorescence spectroscopy. There was no significant encapsulation in polymer synthesized from 4-C-hydroxymethyl-1,2-O-isopropylidene-β-L-threo-pentofuranose because this sugar monomer does not contain a big hydrophobic moiety as the pentyl or the benzylidene moiety. Nile red release study was performed at pH 5.0 and 7.4 using fluorescence spectroscopy. The release of nile red from the polymer bearing benzylidene moiety and pentyl moiety was observed with a half life of 3.4 and 2.0 h, respectively at pH 5.0, whereas no release was found at pH 7.4.

Preoperative and postoperative serial assessments of postural balance and fall risk in patients with arthroscopic anterior cruciate ligament reconstruction.

PubMed

Gokalp, Oguzhan; Akkaya, Semih; Akkaya, Nuray; Buker, Nihal; Gungor, Harun R; Ok, Nusret; Yorukoglu, Cagdas

2016-04-27

Impaired postural balance due to somatosensory data loss with mechanical instability has been shown in patients with ACL deficiency. To assess postural balance in patients with ACL insufficiency prior to surgery and following reconstruction with serial evaluations. Thirty patients (mean age of 27.7 ± 6.7 years) who underwent arthroscopic reconstruction of ACL with bone-patellar tendon-bone autograft were examined for clinical and functional variables at preoperative day and postoperative 12th week. Posturographic analysis were performed by using Tetrax Interactive Balance System (Sunlight Medical Ltd, Israel) at preoperative day, at 4th, 8th, and 12th weeks following reconstruction. Data computed by posturographic software by the considerations of the oscillation velocities of body sways is fall risk as a numeric value (0-100, lower values indicate better condition). All of the patients (mean age of 27.7 ± 6.7 years) had significant improvements for clinical, functional evaluations and fall risk (p< 0.05). Mean fall risk was within high-risk category (59.9 ± 22.8) preoperatively. The highest fall risk was detected at postoperative 4th week. Patients had high fall risk at 8th week similar to preoperative value. Mean fall risk decreased to low level risk at 12th week. Preoperative symptom duration had relationships with preoperative fall risk and postoperative improvement of fall risk (p= 0.001, r= -0.632, p= 0.001, r= -0.870, respectively). The improvement of fall risk was higher in patients with symptoms shorter than 6 months (p= 0.001). According to these results, mean fall risk of patients with ACL insufficiency was within high risk category preoperatively, and fall risk improves after surgical reconstruction, but as the duration of complaints lengthens especially longer than 6 months, the improvement of fall risk decreases following reconstruction.

Simultaneous Increase in Open-Circuit Voltage and Efficiency of Fullerene-Free Solar Cells through Chlorinated Thieno[3,4- b ]thiophene Polymer Donor

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

Wang, Huan; Chao, Pengjie; Chen, Hui

The chlorinated polymer, PBTCl, has been found to be an efficient donor in nonfullerene polymer solar cells (PSCs), which showed a blue-shifted absorbance compared to that of its fluorine analogue (PTB7-th) and resulted in more complementary light absorption with a nonfullerene acceptor, such as ITIC. Meanwhile, chlorine substitution lowered the HOMO level of PBTCl, which increased the open-circuit voltage of the corresponding polymer-based devices. The 2D GIWAXS analysis illustrated that the PBTCl/ITIC blend film exhibited a “face-on” orientation and scattering features of both PBTCl and ITIC, suggesting that the blend of PBTCl and ITIC was phase-separated and formed individual crystallinemore » domains of the donor and acceptor, which promoted charge transfer in the bicontinuous film and eventually elevated the solar energy conversion efficiency. The PBTCl-based nonfullerene PSC exhibited a maximum PCE of 7.57% with a Voc of 0.91 V, which was an approximately 13% increasing in the PCE compared to that of the fluorine-analogue-based device.« less

Multi-thermal observations of newly formed loops in a dynamic flare

NASA Technical Reports Server (NTRS)

Svestka, Zdenek F.; Fontenla, Juan M.; Machado, Marcos E.; Martin, Sara F.; Neidig, Donald F.

1987-01-01

The dynamic flare of November 6, 1980 (max at about 15:26 UT) developed a rich system of growing loops which could be followed in H-alpha for 1.5 hr. Throughout the flare, these loops, near the limb, were seen in emission against the disk. Theoretical computations of deviations from LTE populations for a hydrogen atom reveal that this requires electron densities in the loops close to, or in excess of 10 to the 12th/cu cm. From measured widths of higher Balmer lines the density at the tops of the loops was found to be 4 x 10 to the 12th/cu cm if no nonthermal motions were present, or 5 x 10 to the 11th/cu cm for a turbulent velocity of about 12 km/s. It is now general knowledge that flare loops are initially observed in X-rays and become visible in H-alpha only after cooling. For such a high density, a loop would cool through radiation from 10 to the 7th to 10 to the 4th K within a few minutes so that the dense H-alpha loops should have heights very close to the heights of the X-ray loops. This, however, contradicts the observations obtained by the HXIS and FCS instruments on board SMM which show the X-ray loops at much higher altitudes than the loops in H-alpha. Therefore, it is suggested that the density must have been significantly lower when the loops were formed, and that the flare loops were apparently both shrinking and increasing in density while cooling.

Recurrent convulsions in a thoroughbred foal: management and treatment.

PubMed

May, C J; Greenwood, R E

1977-07-23

A thoroughbred foal had a convulsive attack 12 hours after birth followed by further convulsions on the 10th, 11th and 12th days after birth. It was treated successfully by medication with primidone, feeding by stomach tube and careful nursing.

A chemiluminescence biosensor based on the adsorption recognition function between Fe3O4@SiO2@GO polymers and DNA for ultrasensitive detection of DNA

NASA Astrophysics Data System (ADS)

Sun, Yuanling; Li, Jianbo; Wang, Yanhui; Ding, Chaofan; Lin, Yanna; Sun, Weiyan; Luo, Chuannan

2017-05-01

In this work, a chemiluminescence (CL) biosensor was prepared for ultrasensitive determination of deoxyribonucleic acid (DNA) based on the adsorption recognition function between core-shell Fe3O4@SiO2 - graphene oxide (Fe3O4@SiO2@GO) polymers and DNA. The Fe3O4@SiO2@GO polymers were composed by GO and magnetite nanoparticles. And the core-shell polymers were confirmed by Scanning Electron Microscope (SEM), X-Ray Powder Diffraction (XRD) and Fourier Transform Infrared (FTIR). Then Fe3O4@SiO2@GO was modified by DNA. Based on the principle of complementary base, Fe3O4@SiO2@GO-DNA was introduced to the CL system and the selectivity, sensitivity of DNA detection was significantly improved. The adsorption properties of Fe3O4@SiO2@GO to DNA were researched through the adsorption equilibrium, adsorption kinetic and thermodynamics. Under optimized CL conditions, DNA could be assayed with the linear concentration range of 5.0 × 10- 12-2.5 × 10- 11 mol/L. The detection limit was 1.7 × 10- 12 mol/L (3δ) and the relative standard deviation (RSD) was 3.1%. The biosensor was finally used for the determination of DNA in laboratory samples and recoveries ranged from 99% to 103%. The satisfactory results revealed the potential application of Fe3O4@SiO2@GO-DNA-CL biosensor in the diagnosis and the treatment of human genetic diseases.

In vivo evaluation of anionic thiolated polymers as oral delivery systems for efflux pump inhibition.

PubMed

Palmberger, Thomas F; Laffleur, Flavia; Greindl, Melanie; Bernkop-Schnürch, Andreas

2015-08-01

Recently, the cationic polymer thiolated chitosan has been reported to modulate drug absorption by inhibition of intestinal efflux pumps. The objective of this study was to evaluate in vitro and in vivo whether thiolated anionic biopolymers also show an efflux pump inhibitory effect in order to improve intestinal transcellular drug uptake. Therefore, three thiomers have been synthesized due covalent attachment of cysteine to various polymer backbones: pectin-cysteine (pect-cys), carboxymethylcellulose-cysteine (CMC-cys) and alginate-cysteine (alg-cys). In vitro, the permeation enhancing properties of these thiomers and their corresponding unmodified polymers have been evaluated on rat small intestine in Ussing-type chambers, using sulforhodamine 101 (SR-101) as MRP2 model substrate. In comparison to buffer only, SR-101 transport in presence of pect-cys, CMC-cys and alg-cys was improved 1.5-fold, 1.8-fold and 3.0-fold, respectively. Due to the comparatively best in vitro performance of thiolated alginate, it has been chosen for in vivo studies: a SR-101 solution containing 4% (w/v) alg-cys led to an AUC0 ≥ 12 of SR-101 of 109 ng ml(-1)h in rats representing a 3.8-fold improvement in comparison to a SR-101 buffer solution. Unmodified alginate improved the AUC0 ≥ 12 of SR-101 by a factor of 1.9. These findings suggest thiolated alginate as promising auxiliary agent for drugs being anionic efflux pump substrates, since the oral bioavailability of a MRP2 substrate could be significantly improved. Copyright © 2015 Elsevier B.V. All rights reserved.

Development and evaluation of camptothecin loaded polymer stabilized nanoemulsion: Targeting potential in 4T1-breast tumour xenograft model.

PubMed

Sugumaran, Abimanyu; Ponnusamy, Chandrasekar; Kandasamy, Palanivel; Krishnaswami, Venkateshwaran; Palanichamy, Rajaguru; Kandasamy, Ruckmani; Lakshmanan, Manikandan; Natesan, Subramanian

2018-04-30

Targeted delivery of anticancer agents is poised to improve cancer therapy, for which polymers can serve as targeting ligands or nanocarriers for chemotherapeutic agents. In this study, we have developed and evaluated the efficacy of a camptothecin (CPT)-loaded polymer stabilized nanoemulsion (PSNE) for the passive targeted delivery to breast cancer. Based on the pseudo-ternary phase diagrams, PSNEs were developed using capmul MCM:poloxamer 407 (4:1), solutol HS 15:simulsol P23 (1:2) and water. CPT polymer mixture was developed by solvent evaporation technique. The PSNEs were characterized for droplet size distribution, plasma protein adsorption, drug release, in-vivo targeting potential, hemolytic potential, cytotoxicity, genotoxicity, in-vivo biodistribution and CPT lactone ring stability. The developed PSNEs showed uniform droplet distribution, extended drug release (76.59±6.12% at 24h), acceptable hemolytic potential, significant cytotoxicity (IC 50 =176±4.3ng/mL) and genotoxicity against MCF-7 cancer cells but low DNA damage potential in human peripheral blood lymphocytes. The efficiency of PSNEs for the targeted delivery of CPT into the tumour regions was documented in 4T1-breast tumour xenografted BALB/c mice. In-vivo biodistribution study shows that 7105.84±568.46ng/g of CPT was passively targeted from PSNE to breast cancer tissue. About 80% of the lactone form was stable for 24h. Taken together, our study provides a promising strategy for developing PSNE-targeted drug delivery system for the breast cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects on Photovoltaic Performance of Dialkyloxy-benzothiadiazole Copolymers by Varying the Thienoacene Donor.

PubMed

Kini, Gururaj P; Oh, Sora; Abbas, Zaheer; Rasool, Shafket; Jahandar, Muhammad; Song, Chang Eun; Lee, Sang Kyu; Shin, Won Suk; So, Won-Wook; Lee, Jong-Cheol

2017-04-12

A series of four donor-acceptor alternating copolymers based on dialkyloxy-benzothiadiazole (ROBT) as an acceptor and thienoacenes as donor units were synthesized and tested for polymer solar cells (PSCs). These new polymers had different donor units with varied electron-donating ability (thieno[3,2-b]thiophene (TT), dithieno[3,2-b:2',3'-d]thiophene (DTT), benzo[1,2-b:4,5-b']dithiophene (BDT), and naphtha[1,2-b:5,6-b']dithiophene (NDT)) in the polymer backbone. To understand the effect of these thienoacenes on the optoelectronic and photovoltaic properties of the copolymers, we systematically analyzed and compared the energy levels, crystallinity, morphology, charge recombination, and charge carrier mobility in the resulting polymers. In this series, optimized photovoltaic cells yielded power conversion efficiency (PCE) values of 6.25% (TT), 9.02% (DTT), 6.34% (BDT), and 2.29% (NDT) with different thienoacene donors. The introduction of DTT into the thienoacene-ROBT polymer enabled the generation of well-ordered molecular packings with a π-π stacking distance of 3.72 Å, high charge mobilities, and an interconnected nanofibrillar morphology in blend films. As a result, the PSC employing the polymer with DTT exhibited the highest PCE of 9.02%. Thus, our structure-property relationship studies of thienoacene-ROBT-based polymers emphasize that the molecular design of the polymers must be carefully optimized to develop high efficient PSCs. These findings will help us to understand the impact of the donor thienoacene on the optoelectronic and photovoltaic performance of polymers.

Computational Modeling of Hydroxypropyl-Methylcellulose Acetate Succinate (HPMCAS) and Phenytoin Interactions: A Systematic Coarse-Graining Approach.

PubMed

Huang, Wenjun; Mandal, Taraknath; Larson, Ronald G

2017-03-06

We present coarse-grained (CG) force fields for hydroxypropyl-methylcellulose acetate succinate (HPMCAS) polymers and the drug molecule phenytoin using a bead/stiff spring model, with each bead representing a HPMCAS monomer or monomer side group (hydroxypropyl acetyl, acetyl, or succinyl) or a single phenytoin ring. We obtain the bonded and nonbonded interaction parameters in our CG model using the RDFs from atomistic simulations of short HPMCAS model oligomers (20-mer) and atomistic simulations of phenytoin molecules. The nonbonded interactions are modeled using a LJ 12-6 potential, with separate parameters for each monomer substitution type, which allows heterogeneous polymer chains to be modeled. The cross interaction terms between the polymer and phenytoin CG beads are obtained explicitly from atomistic level polymer-phenytoin simulations, rather than from mixing rules. We study the solvation behavior of 50-mer and 100-mer polymer chains and find chain-length-dependent aggregation. We also compare the phenytoin CG force field developed in this work with that in Mandal et al. (Soft Matter, 2016, 12, 8246-8255) and conclude both are suitable for studying the interaction between polymer and drug in solvated solid dispersion formulation, in the absence of drug crystallization. Finally, we present simulations of heterogeneous HPMCAS model polymer chains and phenytoin molecules. Polymer and drug form a complex in a short period of simulation time due to strong intermolecular interactions. Moreover, the protonated polymer chains are more effective than deprotonated ones in inhibiting the drug aggregation in the polymer-drug complex.

Th1 differentiation drives the accumulation of intravascular, non-protective CD4 T cells during tuberculosis

PubMed Central

Sallin, Michelle A.; Sakai, Shunsuke; Kauffman, Keith D.; Young, Howard A.; Zhu, Jinfang; Barber, Daniel L.

2017-01-01

SUMMARY Recent data indicate that the differentiation state of Th1 cells determines their protective capacity against tuberculosis. Therefore, we examined the role of Th1 polarizing factors in the generation of protective and non-protective subsets of Mtb-specific Th1 cells. We find IL-12/23p40 promotes Th1 cell expansion and maturation beyond the CD73+CXCR3+T-betdim stage, and T-bet prevents deviation of Th1 cells into Th17 cells. Nevertheless, IL-12/23p40 and T-bet are also essential for the production of a prominent subset of intravascular CX3CR1+KLRG1+ Th1 cells that persists poorly and can neither migrate into the lung parenchyma nor control Mtb growth. Furthermore, T-bet suppresses development of CD69+CD103+ tissue resident phenotype effectors in lung. In contrast, Th1 cell-derived IFNγ inhibits the accumulation of intravascular CX3CR1+KLRG1+ Th1 cells. Thus, although IL-12 and T-bet are essential host survival factors, they simultaneously oppose lung CD4 T cell responses at several levels, demonstrating the dual nature of Th1 polarization in tuberculosis. PMID:28355562

New Ag(I)-iminophosphorane coordination polymers as efficient catalysts precursors for the MW-assisted Meyer-Schuster rearrangement of propargylic alcohols in water.

PubMed

García-Álvarez, Joaquín; Díez, Josefina; Vidal, Cristian; Vicent, Cristian

2013-06-03

Treatment of the N-thiophosphorylated iminophosphorane ligands (PTA)═NP(═S)(OR)2 [PTA = 1,3,5-triaza-7-phosphaadamantane, 3a and 3b] and (DAPTA)═NP(═S)(OR)2 [DAPTA = 3,7-diacetyl-1,3,7-triaza-5-bicyclo[3.3.1]nonane, 4a and 4b] with an equimolecular amount of AgSbF6 leads to high-yield formation of the new one-dimensional coordination polymers [Ag{μ(2)-N,S-(PTA)═NP(═S)(OR)2}]x[SbF6]x (5a and 5b) and [Ag{μ(2)-O,S-(DAPTA)═NP(═S)(OR)2}]x[SbF6]x (6a and 6b), respectively. These new (iminophosphorane)silver(I) coordination polymers are efficient catalyst precursors for the Meyer-Schuster isomerization of both terminal and internal alkynols. Reactions proceeded in water, under aerobic conditions and using microwave irradiation as heating source, to afford the corresponding α,β-unsaturated carbonyl compounds in excellent yields, without the addition of any cocatalyst. Remarkably, it should be noted that this catalytic system can be recycled up to 10 consecutive runs (1st cycle 45 min, 99%; 10th cycle 6 h, 97%). ESI-MS analysis of 5a in water has been carried out providing valuable insight into the monomeric active species responsible for catalytic activity in water.

High Ionic Conductivity of Composite Solid Polymer Electrolyte via In Situ Synthesis of Monodispersed SiO2 Nanospheres in Poly(ethylene oxide).

PubMed

Lin, Dingchang; Liu, Wei; Liu, Yayuan; Lee, Hye Ryoung; Hsu, Po-Chun; Liu, Kai; Cui, Yi

2016-01-13

High ionic conductivity solid polymer electrolyte (SPE) has long been desired for the next generation high energy and safe rechargeable lithium batteries. Among all of the SPEs, composite polymer electrolyte (CPE) with ceramic fillers has garnered great interest due to the enhancement of ionic conductivity. However, the high degree of polymer crystallinity, agglomeration of ceramic fillers, and weak polymer-ceramic interaction limit the further improvement of ionic conductivity. Different from the existing methods of blending preformed ceramic particles with polymers, here we introduce an in situ synthesis of ceramic filler particles in polymer electrolyte. Much stronger chemical/mechanical interactions between monodispersed 12 nm diameter SiO2 nanospheres and poly(ethylene oxide) (PEO) chains were produced by in situ hydrolysis, which significantly suppresses the crystallization of PEO and thus facilitates polymer segmental motion for ionic conduction. In addition, an improved degree of LiClO4 dissociation can also be achieved. All of these lead to good ionic conductivity (1.2 × 10(-3) S cm(-1) at 60 °C, 4.4 × 10(-5) S cm(-1) at 30 °C). At the same time, largely extended electrochemical stability window up to 5.5 V can be observed. We further demonstrated all-solid-state lithium batteries showing excellent rate capability as well as good cycling performance.

Autoantibodies to the Rpp25 component of the Th/To complex are the most common antibodies in patients with systemic sclerosis without antibodies detectable by widely available commercial tests.

PubMed

Mahler, Michael; Satoh, Minoru; Hudson, Marie; Baron, Murray; Chan, Jason Y F; Chan, Edward K L; Wick, James; Fritzler, Marvin J

2014-07-01

Antinuclear antibodies (ANA) occur in up to 95% of patients with systemic sclerosis (SSc). In most, SSc-associated antibodies are detected (i.e., centromere, topoisomerase I, RNA polymerase III, PM/Scl, Ro52/TRIM21, and U1RNP). Ribonuclease P protein subunit p25, (Rpp25) is an autoantigenic component of the Th/To complex. The contribution of anti-Th/To and anti-Rpp25 antibodies to ANA positivity in patients with SSc remains unknown. Sera from 873 patients with SSc were tested for ANA, and SSc-associated antibodies were measured. Samples without antibodies to extractable nuclear antigens (ENA; n = 53, ANA+/ENA-), were analyzed by immunoprecipitation (IP) and metabolically labeled proteins and for anti-Rpp25 antibodies (n = 50) by a chemiluminescent immunoassay (CLIA) and Rpp25 ELISA. Anti-Th/To antibodies occurred in 19/53 (36%), as determined by IP, and were the most common autoantibody in ANA+/ENA- SSc. Of those samples, 50/53 were available for additional testing by CLIA and ELISA. Anti-Rpp25 antibodies were detected in 12 (24% CLIA) or 10 (20% ELISA) of 50 patients. Receiver-operating characteristic curve analysis showed similar discrimination between Th/To IP-positive (n = 19) and -negative samples (n = 31) by CLIA and ELISA (area under the curve 0.90 vs 0.87; p = 0.6691). The positive percent agreement between IP and CLIA or ELISA was 12/19 (63.2%, 95% CI 38.4-83.7%) or 10/19 (52.6%, 95% CI 73.3-94.2%), respectively. Negative percent agreement was 100% for both assays. Autoantibodies to the Th/To autoantigen are important in patients with SSc who have been considered negative for SSc-specific or SSc-associated antibodies by widely available commercial assays. Rpp25 can be considered a major target of anti-Th/To antibodies. Assays detecting anti-Th/To and anti-Rpp25 antibodies may be important in SSc.

40 CFR 721.5560 - Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c,e][1,2]oxaphosphorin-6-oxide. 721.5560... Substances § 721.5560 Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H... phenol, reaction products with 6H-dibenz[c,e][1,2]oxaphosphorin-6-oxide. (PMN P-00-991; CAS No. 300371-38...

40 CFR 721.5560 - Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c,e][1,2]oxaphosphorin-6-oxide. 721.5560... Substances § 721.5560 Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H... phenol, reaction products with 6H-dibenz[c,e][1,2]oxaphosphorin-6-oxide. (PMN P-00-991; CAS No. 300371-38...

Decomposition of Time Scales in Linear Systems and Markovian Decision Processes.

DTIC Science & Technology

1980-11-01

this research. I, 3 iv U TABLE OF CONTENTS *Chapter Page *-1. INTRODUCTION .................................................. 1 2. EIGENSTRUCTTJRE...Components ..... o....... 16 2.4. Ordering of State Variables.. ......... ........ 20 2.5. Example - 8th Order Power System Model................ 22 3 ...results. In Chapter 3 we consider the time scale decomposition of singularly perturbed systems. For this problem (1.1) takes the form 12 + u (1.4) 2

Polymer-lipid hybrid systems: merging the benefits of polymeric and lipid-based nanocarriers to improve oral drug delivery.

PubMed

Rao, Shasha; Prestidge, Clive A

2016-01-01

A number of biobarriers limit efficient oral drug absorption; both polymer-based and lipid-based nanocarriers have demonstrated properties and delivery mechanisms to overcome these biobarriers in preclinical settings. Moreover, in order to address the multifaceted oral drug delivery challenges, polymer-lipid hybrid systems are now being designed to merge the beneficial features of both polymeric and lipid-based nanocarriers. Recent advances in the development of polymer-lipid hybrids with a specific focus on their viability in oral delivery are reviewed. Three classes of polymer-lipid hybrids have been identified, i.e. lipid-core polymer-shell systems, polymer-core lipid-shell systems, and matrix-type polymer-lipid hybrids. We focus on their application to overcome the various biological barriers to oral drug absorption, as exemplified by selected preclinical studies. Numerous studies have demonstrated the superiority of polymer-lipid hybrid systems to their non-hybrid counterparts in providing improved drug encapsulation, modulated drug release, and improved cellular uptake. These features have encouraged their applications in the delivery of chemotherapeutics, proteins, peptides, and vaccines. With further research expected to optimize the manufacturing and scaling up processes and in-depth pre-clinical pharmacological and toxicological assessments, these multifaceted drug delivery systems will have significant clinical impact on the oral delivery of pharmaceuticals and biopharmaceuticals.

Strain-dependent release of cytokines modulated by Lactobacillus salivarius human isolates in an in vitro model

PubMed Central

2010-01-01

Background Oral administration of probiotics is known to modulate cytokines profile not only locally, but also systemically. Four strains of Lactobacillus salivarius, LDR0723, BNL1059, RGS1746 and CRL1528, were evaluated for their ability to modulate release of pro- and anti-inflammatory cytokines. Findings Strains were assessed for effects on production of Interleukin-12 (IL-12), Interferon-γ (IFN-γ), Interleukin-4 (IL-4) and Interleukin-5 (IL-5) by incubating bacterial suspensions with THP-1 macrophage like cells. Cytokines were determined by means of specific quantitative enzyme-linked immunosorbent assays. LDR0723 and CRL1528 led to a sustained increment in production of IL-12 and IFN-γ and to a decrease in release of IL-4 and IL-5, while BNL1059 and RGS1746 favoured Th2 response, leading to a decrease in Th1/Th2 ratio with respect to unstimulated cells. Conclusions In conclusion, capability of L. salivarius to modulate immune response was strictly strain dependent and strains of the same species might have opposite effects. Therefore, a careful evaluation of anti-inflammatory properties of lactobacilli should be performed on single strain, before any consideration on potential probiotic use. PMID:20184725

Decreased production of interleukin-12 and type 2 immune responses are marked in cachectic patients with colorectal and gastric cancer.

PubMed

Shibata, Masahiko; Nezu, Takeshi; Kanou, Hisao; Abe, Hideo; Takekawa, Motoo; Fukuzawa, Masahiro

2002-04-01

Balance of the two types of T helper cells is one of the most important factors for regulation of the immune system. This study examines the production of interleukin (IL)-4, -6, -10, -12, and interferon-gamma by peripheral blood mononuclear cells stimulated with phytohemagglutinin or Staphylococcus aureus. Sixty-one patients, including 25 with gastric and 39 with colorectal cancer, and 39 normal volunteers were entered. The production of IL-12 decreased significantly with advancing disease and was lowest in the patients with distant metastases and cachexia. Compared with normal donors, the production of interferon-gamma decreased in all categories of patients, with no difference among patient groups. Levels of Th2 cytokines, such as IL-4, IL-6, and IL-10, also showed no difference among patient groups. However, production of all these cytokines had increased by 2.5 months after sequential testing in the same cachectic patients. The authors' findings indicate that the induction of Th1 cells seems to be suppressed at a relatively early stage of disease, whereas that of Th2 cells seems to increase in the terminal stage.

Model systems for single molecule polymer dynamics

PubMed Central

Latinwo, Folarin

2012-01-01

Double stranded DNA (dsDNA) has long served as a model system for single molecule polymer dynamics. However, dsDNA is a semiflexible polymer, and the structural rigidity of the DNA double helix gives rise to local molecular properties and chain dynamics that differ from flexible chains, including synthetic organic polymers. Recently, we developed single stranded DNA (ssDNA) as a new model system for single molecule studies of flexible polymer chains. In this work, we discuss model polymer systems in the context of “ideal” and “real” chain behavior considering thermal blobs, tension blobs, hydrodynamic drag and force–extension relations. In addition, we present monomer aspect ratio as a key parameter describing chain conformation and dynamics, and we derive dynamical scaling relations in terms of this molecular-level parameter. We show that asymmetric Kuhn segments can suppress monomer–monomer interactions, thereby altering global chain dynamics. Finally, we discuss ssDNA in the context of a new model system for single molecule polymer dynamics. Overall, we anticipate that future single polymer studies of flexible chains will reveal new insight into the dynamic behavior of “real” polymers, which will highlight the importance of molecular individualism and the prevalence of non-linear phenomena. PMID:22956980

Influence of heteroatoms on photovoltaic performance of donor–acceptor copolymers based on 2,6-di(thiophen-2-yl)benzo[1,2-b:4,5-b']difurans and diketopyrrolopyrrole

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

Kobilka, Brandon M.; Hale, Benjamin J.; Ewan, Monique D.

2013-01-01

Donor–acceptor conjugated polymers based on the novel donor 3,7-didodecyl-2,6-di(thiophen-2-yl)benzo[1,2-b:4,5-b']difuran, and 1,4-diketopyrrolo[3,4-c]pyrrole as the acceptor were synthesized via the Stille cross-coupling reaction. The alkyl chains on the diketopyrrolopyrrole monomers were varied to engineer the solubility and morphology of the materials. Thiophene and furan moieties were used to flank the DPP group and the impact of these heterocycles on the polymers' properties evaluated. All of the polymers have similar optoelectronic properties with optical band-gaps of 1.3–1.4 eV, LUMO levels of -3.7 to -3.8 eV and HOMO levels of -5.5 to -5.6 eV. The furan-containing polymers have better solubility than the all-thiophene polymers,more » as significantly higher molecular weight materials of the former were readily dissolved. When the polymers were used as donor materials along with PC71BM as the electron-acceptor in bulk-heterojunction photovoltaic cells, power conversion efficiencies of up to 2.9% were obtained, with the furan-containing polymers giving the best results.« less

Polymer complexes.. XXXX. Supramolecular assembly on coordination models of mixed-valence-ligand poly[1-acrylamido-2-(2-pyridyl)ethane] complexes

NASA Astrophysics Data System (ADS)

El-Sonbati, A. Z.; El-Bindary, A. A.; Diab, M. A.

2003-02-01

The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [( 11)+( 12)] in the paper and in mononuclear polymer complexes ( 1)-( 5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX 2 and KPtCl 4 in the presence of N-heterocyclic base consisting of polymer complexes ( 9)+( 10), and in monouclear compounds ( 6)-( 8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds ( 13)+( 14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.

Polymer complexes. XXXX. Supramolecular assembly on coordination models of mixed-valence-ligand poly[1-acrylamido-2-(2-pyridyl)ethane] complexes.

PubMed

El-Sonbati, A Z; El-Bindary, A A; Diab, M A

2003-02-01

The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [(11)+(12)] in the paper and in mononuclear polymer complexes (1)-(5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX2 and KPtCl4 in the presence of N-heterocyclic base consisting of polymer complexes (9)+(10), and in monouclear compounds (6)-(8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds (13)+(14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.

[The use of polymer gel dosimetry to measure dose distribution around metallic implants].

PubMed

Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

2014-10-01

A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances.

Ontogeny of Daucus carota Infected with Meloidogyne hapla

PubMed Central

Slinger, L. A.; Bird, G. W.

1978-01-01

The ontogeny of carrots (Daucus carota cv. 'Spartan Premium') grown under greenhouse conditions in pots of organic soil infected with Meloidogyne hapla was influenced detrimentally as early as 4 days after seeding, as determined through analysis of plant surface area, dry weight, fresh weight, net assimilation rate, relative growth rate, and leaf-area ratio. Only 58% of the diseased carrots were suitable for fresh market, compared with 97% of those grown in nematode-free soil. Growth and development of the shoot system (height, surface area, dry weight, and fresh weight) were retarded by M. hapla as early as 12 days after seeding. During the first 12 days after seeding, root dry weight was greater for diseased plants than for controls. Root growth and development (surface area, dry weight, and fresh weight) associated with this nematode, however, were retarded as early as 16 days after seeding. M. hapla caused a delay in the occurrence of 2nd-, 4th-, and 5th-order roots, and an increase in the occurrence of 6th-order roots in infected plants. Parasitized plants had 44% fewer roots (primary through 6th-order) and 50% less total root length. PMID:19305837

Assessment of relative flammability and thermochemical properties of some thermoplastic materials

NASA Technical Reports Server (NTRS)

Kourtides, D. A.; Parker, J. A.

1977-01-01

Thermomechanical properties, flammability, oxygen index, relative toxicity of pyrolysis effluents, and char yields were studied for 12 advanced polymers which are candidates for use in aircraft interiors as decorative films, compression- and injection-molded parts and thermoplastic parts. Polymers sampled included polyphenylene sulfide, 9,9 bis (4-hydroxyphenol) fluorene polycarbonate-poly (dimethylsiloxane), polyether sulfone, polyvinyl fluoride and polyvinylidene fluoride. Availability of these samples, whether in commercial form or in test quantities, is specified. An estimate of relative fire resistance for the materials was obtained; the five polymers listed above were found to be the most fire resistant of the 12 sampled.

Layering Transitions and Squeeze-Out Patterns in Nanoscale Polymeric Soap Films

NASA Astrophysics Data System (ADS)

Berg, Steffen; Troian, Sandra M.

2004-11-01

Oscillatory forces in freely suspended or confined nanofilms of micellar solutions, colloidal suspensions, alkanes and semidilute polyelectrolyte films generate stepwise thinning during the final stages of film drainage. The step jump correlates with the basic aggregation unit such as the micellar size or the polymer mesh size. In all studies so far reported, the interface separating films of different thickness is circular or elliptical, as seen in common or Newton black films. Our studies of freely suspended soaps films containing an anionic surfactant and nonionic polymer have revealed that the last stratification event expands with a fractal boundary whose dimension increases with the solution viscosity above a critical value. Unstable front propagation resembles a viscous fingering instability. We propose that internal film layering due to confinement of polymer-surfactant aggregates leads to a smaller viscosity in the thinnest film (≈ 12 nm), which rapidly penetrates into an exterior layer (≈ 62 nm) of higher viscosity. Subsequent coarsening of the fractal interface mimics shapes recently observed in macroscopic systems.

Polymer concrete composites for the production of high strength pipe and linings in high temperature corrosive environments

DOEpatents

Zeldin, A.; Carciello, N.; Fontana, J.; Kukacka, L.

High temperature corrosive resistant, non-aqueous polymer concrete composites are described. They comprise about 12 to 20% by weight of a water-insoluble polymer binder polymerized in situ from a liquid monomer mixture consisting essentially of about 40 to 70% by weight of styrene, about 25 to 45% by weight acrylonitrile and about 2.5 to 7.5% by weight acrylamide or methacrylamide and about 1 to 10% by weight of a crosslinking agent. This agent is selected from the group consisting of trimethylolpropane trimethacrylate and divinyl benzene; and about 80 to 88% by weight of an inert inorganic filler system containing silica sand and portland cement, and optionally Fe/sub 2/O/sub 3/ or carbon black or mica. A free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other organic peroxides and combinations thereof to initiate crosspolymerization of the monomer mixture in the presence of said inorganic filler.

Biodegradable polymers for targeted delivery of anti-cancer drugs.

PubMed

Doppalapudi, Sindhu; Jain, Anjali; Domb, Abraham J; Khan, Wahid

2016-06-01

Biodegradable polymers have been used for more than three decades in cancer treatment and have received increased interest in recent years. A range of biodegradable polymeric drug delivery systems designed for localized and systemic administration of therapeutic agents as well as tumor-targeting macromolecules has entered into the clinical phase of development, indicating the significance of biodegradable polymers in cancer therapy. This review elaborates upon applications of biodegradable polymers in the delivery and targeting of anti-cancer agents. Design of various drug delivery systems based on biodegradable polymers has been described. Moreover, the indication of polymers in the targeted delivery of chemotherapeutic drugs via passive, active targeting, and localized drug delivery are also covered. Biodegradable polymer-based drug delivery systems have the potential to deliver the payload to the target and can enhance drug availability at desired sites. Systemic toxicity and serious side effects observed with conventional cancer therapeutics can be significantly reduced with targeted polymeric systems. Still, there are many challenges that need to be met with respect to the degradation kinetics of the system, diffusion of drug payload within solid tumors, targeting tumoral tissue and tumor heterogeneity.

No Need to Wait for Superman: A Case Study of One Unique High School

ERIC Educational Resources Information Center

Ratcliff, N. J.; Jones, C. R.; Costner, R. H.; Knight, C.; Disney, G.; Savage-Davis, E.; Sheehan, H.; Hunt, G. H.

2012-01-01

Based on a theoretical model developed by Schlechty, this case study focuses on a small high school, located on a college campus and designed to address the educational needs of gifted 9th- through 12th-grade students. Eight teachers who taught 9th- and 12th-grade classes and their 60 students were observed. Each teacher was observed during six…

Relationships between Work Values, Socio-Educational and Work Experiences, and Vocational Aspirations of 6th, 9th, 10th, and 12th Graders

ERIC Educational Resources Information Center

Wijting, Jan P.; And Others

1977-01-01

Using a cross-sectional design and canonical regression analysis, the differential relationships between work values and social, educational, and occupational experiences and aspirations were examined for boys and girls in grades 6, 9, 10, and 12. Support was found for predicted differences in work-values correlates across grades and between…

Progresses in neuroproteomics of neurodegenerative diseases--18th HUPO BPP workshop: September 12, 2012, Boston, USA.

PubMed

Gröttrup, Bernd; May, Caroline; Meyer, Helmut E; Grinberg, Lea T; Park, Young Mok

2013-01-01

The HUPO Brain Proteome Project (HUPO BPP) held its 18(th) workshop in Boston, USA, September 12(th) 2012 during the HUPO 11th Annual Word Congress. The focus was on the progress on the Human Brain Proteome Atlas as well as ideas, strategies and methodological aspects. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Relationship of intentional self-harm using sharp objects with depressive and dissociative tendencies in pre-adolescence-adolescence.

PubMed

Sho, Noriko; Oiji, Arata; Konno, Chizue; Toyohara, Koji; Minami, Tatsuya; Arai, Takashi; Seike, Yoji

2009-06-01

The objectives of the present study were to (i) evaluate the prevalence of children and adolescents who have engaged in intentional self-harm using a sharp object; and (ii) investigate the relationship between self-harm with sharp objects and depressive tendencies or dissociative tendencies. A total of 1938 students in grades 5-12 in Yokohama, Japan, were enrolled, and they completed anonymous self-report questionnaires including a question about intentional self-harm with a sharp object, the Depression Self-Rating Scale for Children (DSRSC) and the Adolescent Dissociative Experiences Scale (A-DES). The prevalence of self-harm using sharp object was 5.4% among male 5th-6th graders, 4.0% among female 5th-6th graders, 5.3% among male 7th-9th graders, 15.1% among female 7th-9th graders, 6.6% among male 10th-12th graders, and 9.6% among female 10th-12th graders. Categorical regression analysis showed that a small amount of variance in self-harm by sharp object was explained by DSRSC and A-DES scores. Self-harm with a sharp object was prevalent among pre-adolescents and adolescents and was associated with depressive and dissociative tendencies.

GROWING ALTERNATIVE SUSTAINABLE BUILDINGS: BIOCOMPOSITE PRODUCTS FROM NATURAL FIBER, BIODEGRADABLE AND RECYCLABLE POLYMER MATERIALS FOR LOAD-BEARING CONSTRUCTION COMPONENTS

EPA Science Inventory

The Phase 2 proposal set out to define a number of limited research objectives to carry the project forward, based on the success of research and design carried out in Phase I through to the development and implementation of the project towards a marketable commodity for th...

TRIAD Annual Spring Meeting (49th) Held in Huntsville, Alabama on May 27, 2010

DTIC Science & Technology

2010-05-27

Northrop Grumman Mission Systems Ms. Mitzi Whittenburg BAE Systems Presentations from the Spring TRIAD will be available to download 1-2 weeks...Ms. Mitzi Whittenburg, C.P.M., BAE Systems, Land & Armaments U.S. Combat Systems (USCS) u Ms. Chireda Gaither, CSC 2:50 pm - 3:00 pm CLOSING...REMARKS u Ms. Diane Dempsey, NDIA TRIAD Co-Chair, Meeting Chair Ms. Mitzi Whittenburg, CPM BAE Systems, Land & Armaments U.S. Combat Systems

Suicidal ideation among students of the 7th, 8th, and 9th grades in the State of Lara, Venezuela: the Global School Health Survey.

PubMed

Granero, Ricardo; Poni, Esteban; Poni, Carolin

2008-12-01

Suicidal behavior among adolescents is not a well-explored public health problem. Health policy decision-making on suicidal behavior needs reliable information on the prevalence of suicidal ideation (SI) and its associated risk factors to produce health promotion and prevention programs. The Global School Health Survey is a self-administered survey done on a random probabilistic sample among students of the 7th, 8th, and 9th grades in the Lara State, Venezuela, school period 2003 to 2004. Point prevalence of SI and associated factors were included and the odds (OR) of having SI was calculated given selected factors. Two-thousand seventy (2070) respondents, of which 13.5 % reported having SI in the last 12 months, and in females more than males (14.6% vs. 11.7%). The OR for SI, according to an associated risk factor, were among (a) females: age > or = 14 years (2.2), worries (3.42), loneliness (8.8), ever had sexual intercourse (5.58), alcohol (8.43) and (b) males: having only one or non close friends (3.69), alcohol (12.36), ever had sexual intercourse (2.73). Behavioral risk factors are relatively new in the field of surveillance systems; therefore, results on SI should be cautiously taken into consideration and a wide discussion should be encouraged as we learn how to best use the results for health promotion and disease prevention.

Polymer encapsulated microcavity optomechanical magnetometer

DOE PAGES

Zhu, Jiangang; Zhao, Guangming; Savukov, Igor; ...

2017-08-21

We demonstrate a magnetometer using polymer encapsulated whispering-gallery-mode microcavity actuated by a micro-magnet. The magnetic field induces force on the micro-magnet causing deformation in the polymer around the microcavity. Subsequently the microcavity detects the change in the refractive index of the polymer resulted from the deformation. This magnetometer works in the frequency range of hertz-to-kilohertz range and achieves a sensitivity of 880 pT/Hz 1/2 at 200 Hz in a micro-scale sensor volume. Polymer encapsulation of the magnetometer and fiber optical connection ensures environmental robustness and practicality of the sensor.

Medium Bandgap Conjugated Polymer for High Performance Polymer Solar Cells Exceeding 9% Power Conversion Efficiency.

PubMed

Jung, Jae Woong; Liu, Feng; Russell, Thomas P; Jo, Won Ho

2015-12-02

Two medium-bandgap polymers composed of benzo[1,2-b:4,5-b']dithiohpene and 2,1,3-benzothiadiazole with 6-octyl-thieno[3,2-b]thiophene as a π-bridge unit are synthesized and their photovoltaic properties are analyzed. The two polymers have deep highest occupied molecular orbital energy levels, high crystallinity, optimal bulk-heterojunction morphology, and efficient charge transport, resulting in a power conversion efficiency of as high as 9.44% for a single-junction polymer solar-cell device. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 58513 - Federal Advisory Committee Act; Technological Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-21

..., 445 12th Street, SW., Washington, DC 20554. DATES: September 27th, 2011. ADDRESSES: Federal Communications Commission, 445 12th Street, SW., Washington, DC 20554. FOR FURTHER INFORMATION CONTACT: Walter... attempt to accommodate as many people as possible. However, admittance will be limited to seating...

77 FR 51842 - Social Security Acquiescence Ruling (AR) 12-X(8); Petersen v. Astrue, 633 F.3d 633 (8th Cir. 2011...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-27

... SOCIAL SECURITY ADMINISTRATION [Docket No. SSA-2012-0046] Social Security Acquiescence Ruling (AR) 12-X(8); Petersen v. Astrue, 633 F.3d 633 (8th Cir. 2011); Whether a National Guard Technician Who.... Acquiescence Ruling 12-X(8) Petersen v. Astrue, 633 F.3d 633 (8th Cir. 2011): Whether a National Guard...

Interleukin-10 Modulation of Virus Clearance and Disease in Mice with Alphaviral Encephalomyelitis.

PubMed

Martin, Nina M; Griffin, Diane E

2018-03-15

Alphaviruses are an important cause of mosquito-borne outbreaks of arthritis, rash, and encephalomyelitis. Previous studies in mice with a virulent strain (neuroadapted SINV [NSV]) of the alphavirus Sindbis virus (SINV) identified a role for Th17 cells and regulation by interleukin-10 (IL-10) in the pathogenesis of fatal encephalomyelitis (K. A. Kulcsar, V. K. Baxter, I. P. Greene, and D. E. Griffin, Proc Natl Acad Sci U S A 111:16053-16058, 2014, https://doi.org/10.1073/pnas.1418966111). To determine the role of virus virulence in generation of immune responses, we analyzed the modulatory effects of IL-10 on disease severity, virus clearance, and the CD4 + T cell response to infection with a recombinant strain of SINV of intermediate virulence (TE12). The absence of IL-10 during TE12 infection led to longer morbidity, more weight loss, higher mortality, and slower viral clearance than in wild-type mice. More severe disease and impaired virus clearance in IL-10 -/- mice were associated with more Th1 cells, fewer Th2 cells, innate lymphoid type 2 cells, regulatory cells, and B cells, and delayed production of antiviral antibody in the central nervous system (CNS) without an effect on Th17 cells. Therefore, IL-10 deficiency led to more severe disease in TE12-infected mice by increasing Th1 cells and by hampering development of the local B cell responses necessary for rapid production of antiviral antibody and virus clearance from the CNS. In addition, the shift from Th17 to Th1 responses with decreased virus virulence indicates that the effects of IL-10 deficiency on immunopathologic responses in the CNS during alphavirus infection are influenced by virus strain. IMPORTANCE Alphaviruses cause mosquito-borne outbreaks of encephalomyelitis, but determinants of outcome are incompletely understood. We analyzed the effects of the anti-inflammatory cytokine IL-10 on disease severity and virus clearance after infection with an alphavirus strain of intermediate virulence. The absence of IL-10 led to longer illness, more weight loss, more death, and slower viral clearance than in mice that produced IL-10. IL-10 influenced development of disease-causing T cells and entry into the brain of B cells producing antiviral antibody. The Th1 pathogenic cell subtype that developed in IL-10-deficient mice infected with a less virulent virus was distinct from the Th17 subtype that developed in response to a more virulent virus, indicating a role for virus strain in determining the immune response. Slow production of antibody in the nervous system led to delayed virus clearance. Therefore, both the virus strain and the host response to infection are important determinants of outcome. Copyright © 2018 American Society for Microbiology.

Vertebral formula and congenital abnormalities of the vertebral column in rabbits.

PubMed

Proks, P; Stehlik, L; Nyvltova, I; Necas, A; Vignoli, M; Jekl, V

2018-06-01

The aim of this retrospective study of 330 rabbits (164 males, 166 females) was to determine different vertebral formulas and prevalence of congenital vertebral anomalies in rabbits from radiographs of the cervical (C), thoracic (Th), lumbar (L) and sacral (S) segments of the vertebral column. The number of vertebrae in each segment of vertebral column, position of anticlinal vertebra and localisation and type of congenital abnormalities were recorded. In 280/330 rabbits (84.8%) with normal vertebral morphology, seven vertebral formulas were identified: C7/Th12/L7/S4 (252/330, 76.4%), C7/Th12/L6/S4 (11/330, 3.3%), C7/Th13/L7/S4 (8/330, 2.4%), C7/Th12/L7/S5 (4/330, 1.2%), C7/Th12/L8/S4 (3/330, 0.9%), C7/Th12/L7/S6 (1/330, 0.3%) and C7/Th11/L7/S4 (1/330, 0.3%). The anticlinal vertebra was identified as Th10 in 56.4% of rabbits and Th11 in 42.4% of rabbits. Congenital spinal abnormalities were identified in 50/330 (15.2%) rabbits, predominantly as a single pathology (n=44). Transitional vertebrae represented the most common abnormalities (n=41 rabbits) in the thoracolumbar (n=35) and lumbosacral segments (n=6). Five variants of thoracolumbar transitional vertebrae were identified. Cervical butterfly vertebrae were detected in three rabbits. One rabbit exhibited three congenital vertebral anomalies: cervical block vertebra, thoracic hemivertebra and thoracolumbar transitional vertebra. Five rabbits exhibited congenital vertebral abnormalities with concurrent malalignment, specifically cervical kyphosis/short vertebra (n=1), thoracic lordoscoliosis/thoracolumbar transitional vertebrae (n=1), thoracic kyphoscoliosis/wedge vertebrae (n=2) and thoracolumbar lordoscoliosis/thoracolumbar transitional vertebrae/lumbosacral transitional vertebrae (n=1). These findings suggest that vertebral columns in rabbits display a wide range of morphologies, with occasional congenital malformations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Polymer therapeutics: concepts and applications.

PubMed

Haag, Rainer; Kratz, Felix

2006-02-13

Polymer therapeutics encompass polymer-protein conjugates, drug-polymer conjugates, and supramolecular drug-delivery systems. Numerous polymer-protein conjugates with improved stability and pharmacokinetic properties have been developed, for example, by anchoring enzymes or biologically relevant proteins to polyethylene glycol components (PEGylation). Several polymer-protein conjugates have received market approval, for example the PEGylated form of adenosine deaminase. Coupling low-molecular-weight anticancer drugs to high-molecular-weight polymers through a cleavable linker is an effective method for improving the therapeutic index of clinically established agents, and the first candidates have been evaluated in clinical trials, including, N-(2-hydroxypropyl)methacrylamide conjugates of doxorubicin, camptothecin, paclitaxel, and platinum(II) complexes. Another class of polymer therapeutics are drug-delivery systems based on well-defined multivalent and dendritic polymers. These include polyanionic polymers for the inhibition of virus attachment, polycationic complexes with DNA or RNA (polyplexes), and dendritic core-shell architectures for the encapsulation of drugs. In this Review an overview of polymer therapeutics is presented with a focus on concepts and examples that characterize the salient features of the drug-delivery systems.

Cylodextrin Polymer Nitrate

NASA Technical Reports Server (NTRS)

Kosowski, Bernard; Ruebner, Anja; Statton, Gary; Robitelle, Danielle; Meyers, Curtis

2000-01-01

The development of the use of cyclodextrin nitrates as possible components of insensitive, high-energy energetics is outlined over a time period of 12 years. Four different types of cyclodextrin polymers were synthesized, nitrated, and evaluated regarding their potential use for the military and aerospace community. The synthesis of these novel cyclodextrin polymers and different nitration techniques are shown and the potential of these new materials is discussed.

Polyestercarbonates which exhibit improved processibility

DOEpatents

Krabbenhoft, Herman Otto

1999-01-01

The invention relates to a polyestercarbonate polymer which comprises repeating units of a mono-unsaturated aliphatic dicarboxylic acid having about 12 to about 20 carbon atoms. Preferred dicarboxylic acids for incorporation into the polymer are cis-octadec-9-enedioic acid or trans-octadec-9-enedioic acid. The use of these mono-unsaturated acids results in polymers with lower glass transition temperatures, and enhances processibility.

Viscosity of the oil-in-water Pickering emulsion stabilized by surfactant-polymer and nanoparticle-surfactant-polymer system

NASA Astrophysics Data System (ADS)

Sharma, Tushar; Kumar, G. Suresh; Chon, Bo Hyun; Sangwai, Jitendra S.

2014-11-01

Information on the viscosity of Pickering emulsion is required for their successful application in upstream oil and gas industry to understand their stability at extreme environment. In this work, a novel formulation of oil-in-water (o/w) Pickering emulsion stabilized using nanoparticle-surfactant-polymer (polyacrylamide) system as formulated in our earlier work (Sharma et al., Journal of Industrial and Engineering Chemistry, 2014) is investigated for rheological stability at high pressure and high temperature (HPHT) conditions using a controlled-strain rheometer. The nanoparticle (SiO2 and clay) concentration is varied from 1.0 to 5.0 wt%. The results are compared with the rheological behavior of simple o/w emulsion stabilized by surfactant-polymer system. Both the emulsions exhibit non-Newtonian shear thinning behavior. A positive shift in this behavior is observed for surfactant-polymer stabilized emulsion at high pressure conditions. Yield stress is observed to increase with pressure for surfactant-polymer emulsion. In addition, increase in temperature has an adverse effect on the viscosity of emulsion stabilized by surfactant-polymer system. In case of nanoparticle-surfactant-polymer stabilized o/w emulsion system, the viscosity and yield stress are predominantly constant for varying pressure and temperature conditions. The viscosity data for both o/w emulsion systems are fitted by the Herschel-Bulkley model and found to be satisfactory. In general, the study indicates that the Pickering emulsion stabilized by nanoparticle-surfactant-polymer system shows improved and stable rheological properties as compared to conventional emulsion stabilized by surfactant-polymer system indicating their successful application for HPHT environment in upstream oil and gas industry.

[Characteristics of tenocyte adhesion to biologically-modified surface of polymer].

PubMed

Qin, Tingwu; Yang, Zhiming; Xie, Huiqi; Li, Hong; Qin, Jian; Wu, Zezhi; Xu, Shirong; Cai, Shaoxi

2002-12-01

In this study we examined the in vitro characteristics of tenocyte adhesion to biologically-modified surface of polymer. Polylactic-co-glycolic acid (PLGA) 85/15 films were prepared by a solvent-casting technique. Each film was adhered onto the bottom of a chamber. The film was precoated with poly-D-lysine (PDL), and then coated with serum-free F12 medium containing various concentrations of fibronectin (FN), type I collagen (CN I), and insulin-like growth factor1 (IGF-1). The monoclonal antibodies (to FN and to CN I) with various dilutions were used to inhibit attachment of tenocytes to surface precoated with FN or CN I. Human embryonic tendon cells (HETCs) and transformed human embryonic tendon cells (THETCs) were used as the seeding cells. The system used for the measurement of adhesion force was the micropipette aspiration experiment system. The micropipette was manipulated to aspirate a small portion of the tenocyte body by using a small aspiration pressure. Then the pipette was pulled away from the adhesion area by micromanipulation. The minimum force required to detach the tenocyte from the substrate was defined as the adhesion force. The results showed that modification of FN or CN I by precoating significantly enhanced attachment of tenocytes to surface of polymer (P < 0.05). As antibodies to FN or CN I were added to a polymer film precoated with FN or CN I, the adhesion force decreased significantly (P < 0.05). We concluded that the specific adhesion forces of tenocytes to extracellular matrix adhesion proteins (FN and CN I) had coordinated action and showed good dependence on their precoating concentrations, and were inhibited by the antibodies to these adhesion proteins. Films precoated with IGF-1 strongly accelerated the adhesion of tenocytes to polymer. These results indicate that the specific adhesion of tenocytes to polymer can be promoted by coating extracellular matrix adhesive proteins and insulin-like growth factor1. It is of great importance to construct tissue-engineered tendon.

The Contribution to Adolescent Well-Being Made by Nonfamily Adults: An Examination of Developmental Assets as Contexts and Processes

ERIC Educational Resources Information Center

Scales, Peter C.; Benson, Peter L.; Mannes, Marc

2006-01-01

The contribution of nonfamily adults to young people's well-being was explored using both a cross-sectional national sample of 614 12- to 17-year-olds and a longitudinal sample of 370 students followed from 6th-8th grades through 10th-12th grades. Both variable- and person-centered analyses were employed. Young people's involvement in…

Making the Grade: Do Nebraska Teachers and Administrators Working in Public Schools in 7th-12th Grade Settings Agree about What Constitutes Sound Grading Practice?

ERIC Educational Resources Information Center

Olson, Mark E.

2013-01-01

In this study, the researcher sought to determine whether Nebraska teachers and administrators agreed about what constitutes sound grading practice. The results of this study indicated that Nebraska teachers and administrators working in public schools in 7th-12th grade settings did not always agree about what constituted sound grading practice.…

Influence of Skip Patterns on Item Non-Response in a Substance Use Survey of 7th to 12th Grade Students

ERIC Educational Resources Information Center

Ding, Kele; Olds, R. Scott; Thombs, Dennis L.

2009-01-01

This retrospective case study assessed the influence of item non-response error on subsequent response to questionnaire items assessing adolescent alcohol and marijuana use. Post-hoc analyses were conducted on survey results obtained from 4,371 7th to 12th grade students in Ohio in 2005. A skip pattern design in a conventional questionnaire…

Nonsuicidal Self-Injury among "Privileged" Youths: Longitudinal and Cross-Sectional Approaches to Developmental Process

ERIC Educational Resources Information Center

Yates, Tuppett M.; Tracy, Allison J.; Luthar, Suniya S.

2008-01-01

This investigation examined process-level pathways to nonsuicidal self-injury (NSSI; e.g., self-cutting, -burning, -hitting) in 2 cohorts of suburban, upper-middle-class youths: a cross-sectional sample of 9th-12th graders (n = 1,036, 51.9% girls) on the West Coast and a longitudinal sample followed annually from the 6th through 12th grades (n =…

The Advanced Program of Vocational Agriculture in Louisiana. Ag III and Ag IV (11th and 12th Grades). Volume II. Bulletin No. 1725.

ERIC Educational Resources Information Center

Louisiana State Dept. of Education, Baton Rouge. Div. of Vocational Education.

This curriculum guide consists of materials for use in teaching an advanced course in agricultural mechanics designed for 11th and 12th grade students. Addressed in the individual units of the guide are arc welding; oxy-acetylene welding; soldering; electricity; tractor maintenance, operation, and safety; small engines; farm structures; and cold…

Engineered Polymers for Advanced Drug Delivery

PubMed Central

Kim, Sungwon; Kim, Jong-Ho; Jeon, Oju; Kwon, Ick Chan; Park, Kinam

2009-01-01

Engineered polymers have been utilized for developing advanced drug delivery systems. The development of such polymers has caused advances in polymer chemistry, which, in turn, has resulted in smart polymers that can respond to changes in environmental condition, such as temperature, pH, and biomolecules. The responses vary widely from swelling/deswelling to degradation. Drug-polymer conjugates and drug-containing nano/micro-particles have been used for drug targeting. Engineered polymers and polymeric systems have also been used in new areas, such as molecular imaging as well as in nanotechnology. This review examines the engineered polymers that have been used as traditional drug delivery and as more recent applications in nanotechnology. PMID:18977434

High-Performance Polymers Sandwiched with Chemical Vapor Deposited Hexagonal Boron Nitrides as Scalable High-Temperature Dielectric Materials.

PubMed

Azizi, Amin; Gadinski, Matthew R; Li, Qi; AlSaud, Mohammed Abu; Wang, Jianjun; Wang, Yi; Wang, Bo; Liu, Feihua; Chen, Long-Qing; Alem, Nasim; Wang, Qing

2017-09-01

Polymer dielectrics are the preferred materials of choice for power electronics and pulsed power applications. However, their relatively low operating temperatures significantly limit their uses in harsh-environment energy storage devices, e.g., automobile and aerospace power systems. Herein, hexagonal boron nitride (h-BN) films are prepared from chemical vapor deposition (CVD) and readily transferred onto polyetherimide (PEI) films. Greatly improved performance in terms of discharged energy density and charge-discharge efficiency is achieved in the PEI sandwiched with CVD-grown h-BN films at elevated temperatures when compared to neat PEI films and other high-temperature polymer and nanocomposite dielectrics. Notably, the h-BN-coated PEI films are capable of operating with >90% charge-discharge efficiencies and delivering high energy densities, i.e., 1.2 J cm -3 , even at a temperature close to the glass transition temperature of polymer (i.e., 217 °C) where pristine PEI almost fails. Outstanding cyclability and dielectric stability over a straight 55 000 charge-discharge cycles are demonstrated in the h-BN-coated PEI at high temperatures. The work demonstrates a general and scalable pathway to enable the high-temperature capacitive energy applications of a wide range of engineering polymers and also offers an efficient method for the synthesis and transfer of 2D nanomaterials at the scale demanded for applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Graphene Nanoplatelet-Polymer Chemiresistive Sensor Arrays for the Detection and Discrimination of Chemical Warfare Agent Simulants.

PubMed

Wiederoder, Michael S; Nallon, Eric C; Weiss, Matt; McGraw, Shannon K; Schnee, Vincent P; Bright, Collin J; Polcha, Michael P; Paffenroth, Randy; Uzarski, Joshua R

2017-11-22

A cross-reactive array of semiselective chemiresistive sensors made of polymer-graphene nanoplatelet (GNP) composite coated electrodes was examined for detection and discrimination of chemical warfare agents (CWA). The arrays employ a set of chemically diverse polymers to generate a unique response signature for multiple CWA simulants and background interferents. The developed sensors' signal remains consistent after repeated exposures to multiple analytes for up to 5 days with a similar signal magnitude across different replicate sensors with the same polymer-GNP coating. An array of 12 sensors each coated with a different polymer-GNP mixture was exposed 100 times to a cycle of single analyte vapors consisting of 5 chemically similar CWA simulants and 8 common background interferents. The collected data was vector normalized to reduce concentration dependency, z-scored to account for baseline drift and signal-to-noise ratio, and Kalman filtered to reduce noise. The processed data was dimensionally reduced with principal component analysis and analyzed with four different machine learning algorithms to evaluate discrimination capabilities. For 5 similarly structured CWA simulants alone 100% classification accuracy was achieved. For all analytes tested 99% classification accuracy was achieved demonstrating the CWA discrimination capabilities of the developed system. The novel sensor fabrication methods and data processing techniques are attractive for development of sensor platforms for discrimination of CWA and other classes of chemical vapors.

Novel lectin-modified poly(ethylene-co-vinyl acetate) mucoadhesive nanoparticles of carvedilol: preparation and in vitro optimization using a two-level factorial design.

PubMed

Varshosaz, Jaleh; Moazen, Ellaheh

2014-08-01

Carvedilol used in cardiovascular diseases has systemic bioavailability of 25-35%. The objective of this study was production of lectin-modified poly(ethylene-co-vinyl acetate) (PEVA) as mucoadhesive nanoparticles to enhance low oral bioavailability of carvedilol. Nanoparticles were prepared by the emulsification-solvent evaporation method using a two-level factorial design. The studied variables included the vinyl acetate content of the polymer, drug and polymer content. Surface modification of PEVA nanoparticles with lectin was carried out by the adsorption method and coupling efficiency was determined using the Bradford assay. Mucoadhesion of nanoparticles was studied on mucin. The particle size, polydispersity index, zeta potential, drug loading and drug release from nanoparticles were studied. The morphology of nanoparticles and crystalline status of the entrapped drug were studied by SEM, DSC and XRD tests, respectively. Results showed the most effective factor on particle size and zeta potential was the interaction of polymer and drug content while, drug loading efficiency and mucoadhesion were more affected by the interaction of polymer type and drug content. Drug concentration was the most effective variable on the drug release rate. The drug was in amorphous state in nanoparticles. The optimum nanoparticles obtained by 45 mg of copolymer contained 12% vinyl acetate/4.3 ml of organic phase and drug concentration of 37.5 wt% of polymer.

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2'-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

Elaboration of m-cresol polyamide12/ polyaniline composite films for antistatic applications

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

Mezdour, D.; Tabellout, M.; Bardeau, J.-F

2013-12-16

The present work deals with the preparation of transparent antistatic films from an extreme dilution of an intrinsically conducting polymer (ICP) with not coloured polymers. Our approach is based on the chemical polymerization of a very thin layer of Polyaniline (PANI) around particles of an insulating polymer (PA12). Films were obtained by dissolving the synthesized core-shell particles in m-Cresol. The electric property and structure relationships were investigated by using dielectric relaxation spectroscopy, X-ray diffraction and micro-Raman spectroscopy. Composite films exhibited a well established dc conductivity over all the frequency range for 10 wt. % of PANI concentration related to themore » conductive properties of the PANI clusters. X-ray diffraction data show broader and lower intensity of PA12 peaks when increasing PANI content, probably due to the additional doping effect of m- cresol. The doping of PA12/PANI films with Dodecyl benzene sulfonic acid (DBSA) was unequivocally verified by Raman spectroscopy.« less

Shape memory polymer medical device

DOEpatents

Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA

2010-06-29

A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

Evaluation of Matrix Tablets Based on Eudragit®E100/Carbopol®971P Combinations for Controlled Release and Improved Compaction Properties of Water Soluble Model Drug Paracetamol.

PubMed

Obeidat, Wasfy M; Nokhodchi, Ali; Alkhatib, Hatim

2015-10-01

The purpose of this work was to investigate the influence of Eudragit®E100 polymer in modifying the release rates and compaction properties of water soluble model drug paracetamol from Carbopol®971P NF polymer matrix tablets prepared by direct compression. The effects of the ratio of the two polymers, the total polymeric content, and the tablets mechanical strength on paracetamol release rates were investigated. Dissolution studies were conducted using USP XX Π rotating paddle apparatus at 50 rpm and 37°C at three different stages (pH 1.2, 4.8, and 6.8). Results showed that the polymers combination improved significantly the compaction properties of paracetamol tablets as evident by the higher crushing strengths (8.3 ± 0.4 Kp) compared to polymer-free tablets (3.4 ± 0.2 Kp) at intermediate compression pressure of 490 MPa. When combined with Carbopol®971P NF, Eudragit®E100 was found to be capable of extending paracetamol release for more than 12 h compared to 1 h for polymers-free tablets. The combined polymers were able to control paracetamol release in a pH independent pattern. The f2 (similarity factor) analysis showed that the ratio between the polymers and the total polymer concentration exhibited significant impact on drug release rates. In conclusion, Eudragit®E100 when combined with Carbopol®971P NF was capable of improving the compaction and sustained release properties of paracetamol. Korsmeyer-Peppas model was found to be the most suitable for fitting drug release data. The polymer combinations can potentially be used to control the release rates of highly water soluble drugs.

Novel degradable co-polymers of polypyrrole support cell proliferation and enhance neurite out-growth with electrical stimulation.

PubMed

Durgam, Hymavathi; Sapp, Shawn; Deister, Curt; Khaing, Zin; Chang, Emily; Luebben, Silvia; Schmidt, Christine E

2010-01-01

Synthetic polymers such as polypyrrole (PPy) are gaining significance in neural studies because of their conductive properties. We evaluated two novel biodegradable block co-polymers of PPy with poly(epsilon-caprolactone) (PCL) and poly(ethyl cyanoacrylate) (PECA) for nerve regeneration applications. PPy-PCL and PPy-PECA co-polymers can be processed from solvent-based colloidal dispersions and have essentially the same or greater conductivity (32 S/cm for PPy-PCL, 19 S/cm for PPy-PECA) compared to the PPy homo-polymer (22 S/cm). The PPy portions of the co-polymers permit electrical stimulation whereas the PCL or PECA blocks enable degradation by hydrolysis. For in vitro tests, films were prepared on polycarbonate sheets by air brushing layers of dispersions and pressing the films. We characterized the films for hydrolytic degradation, electrical conductivity, cell proliferation and neurite extension. The co-polymers were sufficient to carry out electrical stimulation of cells without the requirement of a metallic conductor underneath the co-polymer film. In vitro electrical stimulation of PPy-PCL significantly increased the number of PC12 cells bearing neurites compared to unstimulated PPy-PCL. For in vivo experiments, the PPy co-polymers were coated onto the inner walls of nerve guidance channels (NGCs) made of the commercially available non-conducting biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV). The NGCs were implanted in a 10 mm defect made in the sciatic nerve of rats, and harvested after 8 weeks. Histological staining showed axonal growth. The studies indicated that these new conducting degradable biomaterials have good biocompatibility and support proliferation and growth of PC12 cells in vitro (with and without electrical stimulation) and neurons in vivo (without electrical stimulation).

Performance comparison of protonic and sodium phosphomolybdovanadate polyoxoanion catholytes within a chemically regenerative redox cathode polymer electrolyte fuel cell

NASA Astrophysics Data System (ADS)

Ward, David B.; Gunn, Natasha L. O.; Uwigena, Nadine; Davies, Trevor J.

2018-01-01

The direct reduction of oxygen in conventional polymer electrolyte fuel cells (PEFCs) is seen by many researchers as a key challenge in PEFC development. Chemically regenerative redox cathode (CRRC) polymer electrolyte fuel cells offer an alternative approach via the indirect reduction of oxygen, improving durability and reducing cost. These systems substitute gaseous oxygen for a liquid catalyst that is reduced at the cathode then oxidised in a regeneration vessel via air bubbling. A key component of a CRRC system is the liquid catalyst or catholyte. To date, phosphomolybdovanadium polyoxometalates with empirical formula H3+nPVnMo12-nO40 have shown the most promise for CRRC PEFC systems. In this work, four catholyte formulations are studied and compared against each other. The catholytes vary in vanadium content, pH and counter ion, with empirical formulas H6PV3Mo9O40, H7PV4Mo8O40, Na3H3PV3Mo9O40 and Na4H3PV4Mo8O40. Thermodynamic properties, cell performance and regeneration rates are measured, generating new insights into how formulation chemistry affects the components of a CRRC system. The results include the best CRRC PEFC performance reported to date, with noticeable advantages over conventional PEFCs. The optimum catholyte formulation is then determined via steady state tests, the results of which will guide further optimization of the catholyte formulation.

Operational frequency stability of rubidium and cesium frequency standards

NASA Technical Reports Server (NTRS)

Lavery, J. E.

1973-01-01

The frequency stabilities under operational conditions of several commercially available rubidium and cesium frequency standards were determined from experimental data for frequency averaging times from 10 to the 7th power s and are presented in table and graph form. For frequency averaging times between 10 to the 5th power and 10 to the 7th power s, the rubidium standards tested have a stability of between 10 to the minus 12th power and 5 x 10 to the minus 12th power, while the cesium standards have a stability of between 2 x 10 to the minus 13th power and 5 x 10 to the minus 13th power.

Designing polymers with sugar-based advantages for bioactive delivery applications.

PubMed

Zhang, Yingyue; Chan, Jennifer W; Moretti, Alysha; Uhrich, Kathryn E

2015-12-10

Sugar-based polymers have been extensively explored as a means to increase drug delivery systems' biocompatibility and biodegradation. Here,we review he use of sugar-based polymers for drug delivery applications, with a particular focus on the utility of the sugar component(s) to provide benefits for drug targeting and stimuli responsive systems. Specifically, numerous synthetic methods have been developed to reliably modify naturally-occurring polysaccharides, conjugate sugar moieties to synthetic polymer scaffolds to generate glycopolymers, and utilize sugars as a multifunctional building block to develop sugar-linked polymers. The design of sugar-based polymer systems has tremendous implications on both the physiological and biological properties imparted by the saccharide units and are unique from synthetic polymers. These features include the ability of glycopolymers to preferentially target various cell types and tissues through receptor interactions, exhibit bioadhesion for prolonged residence time, and be rapidly recognized and internalized by cancer cells. Also discussed are the distinct stimuli-sensitive properties of saccharide-modified polymers to mediate drug release under desired conditions. Saccharide-based systems with inherent pH- and temperature-sensitive properties, as well as enzyme-cleavable polysaccharides for targeted bioactive delivery, are covered. Overall, this work emphasizes inherent benefits of sugar-containing polymer systems for bioactive delivery.

Electrically conducting polymers for aerospace applications

NASA Technical Reports Server (NTRS)

Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. R.; Meador, Michael A.

1991-01-01

Current research on electrically conducting polymers from 1974 to the present is reviewed focusing on the development of materials for aeronautic and space applications. Problems discussed include extended pi-systems, pyrolytic polymers, charge-transfer systems, conductive matrix resins for composite materials, and prospects for the use of conducting polymers in space photovoltaics.

Effect of Processing Parameters on the Morphology of PVDF Electrospun Nanofiber

NASA Astrophysics Data System (ADS)

Zulfikar, M. A.; Afrianingsih, I.; Nasir, M.; Alni, A.

2018-03-01

Electrospinning is a process that produces continuous polymer fibers with diameters in the submicron range through the action of an external electric field imposed on a polymer solution or melt. Because of the tiny diameter in several hundreds of nanometers and the high porosity, electrospun membranes show potential applications in extensive areas such as filtration systems, biomedical tissue templates, drug delivery membranes, and so on. In the electrospinning process, some parameters such as polymer concentration, feeding rate of the polymer solution, additives, humidity, viscosity, surface tension, applied voltage, and nozzle-to ground collector distance will affect the fiber diameter and morphology. In this work, we have evaluated the effects of two processing parameters including the flow rate of the polymer solution and nozzle-to ground collector distance, on the morphology of the fibers formed. The solutions used in the electrospinning experiments were prepared using Poly(vinylidene fluoride) (PVDF). This material was dissolved in N,N-dimethylformamide (DMF) to make solutions with concentrations of 20 wt%. These solutions was electrospun using a 5 mL plastic syringe with an 8 gauge stainless needle at an applied voltage of 20.0 kV, a flow rate of 0.02-0.04 mL/min and nozzle-to ground collector distance of 12 and 15 cm. Electrospinning of PVDF polymer solution was performed in horizontal alignment having a grounded aluminum foil which serves as a collector. The nanofibers obtained were characterized by polarizing optical microscope. We find that the low flow rate of the polymer solution and nozzle-to ground collector distance are strongly correlated with the formation of bead defects in the fibers.

Passage from normal mucosa to adenoma and colon cancer: alteration of normal sCD30 mechanisms regulating TH1/TH2 cell functions.

PubMed

Contasta, Ida; Berghella, Anna Maria; Pellegrini, Patrizia; Adorno, Domenico

2003-08-01

The pathogenesis of cancer is currently under intensive investigation to identify reliable prognostic indices for the early detection of disease. Adenomas have been identified as precursors of colorectal cancer and tumor establishment, and disease progression has been found to reflect a malfunction of the immune system. On the basis of the role of the CD30 molecule in the regulation of TH1/TH2 functions and our previous results, strongly suggesting the validity of serum TH1/TH2 cytokines in the study of tumor progression, we studied network interaction between the production of soluble (s) CD30/sBCl2 in whole blood culture [in basic conditions and after PHA, LPS, and anti-CD3 monoclonal antibody (mAb) stimulation] and levels of TH1/TH2 cytokines (IL2, IFN gamma, IL12, IL4, IL5, IL10). Peripheral blood from a group of healthy subjects, as well as from patients with adenoma and colorectal cancer was used. Our objective was to gain a better insight into the role of the CD30 molecule in the passage from normal mucosa to adenoma and tumor and identify specific disease markers. Our results suggest that the decrease in CD30 expression and the abnormal increase in Bcl2 expression, observed in the peripheral cells of both adenoma and tumor groups determine an imbalance between TH1/TH2 functions. Consequently, changes in sCD30/sBcl2 culture production and TH1/TH2 cytokine serum levels may be reliable markers for tumor progression. In fact, our overall data show that a decrease of sCD30 levels in basic and PHA conditions and an increase of IFN gamma, IL4, IL5, and IL12 serum levels and sBcl2 in all activation condition are indicative of the passage from normal mucosa to adenoma; whilst a decrease of sBcl2 level in basic, LPS and anti-CD3 conditions and of IL2, IFN gamma serum levels, together with an increase of IL5 are indicative of the passage from adenoma to tumor.

Ultra fast polymer network blue phase liquid crystals

NASA Astrophysics Data System (ADS)

Hussain, Zakir; Masutani, Akira; Danner, David; Pleis, Frank; Hollfelder, Nadine; Nelles, Gabriele; Kilickiran, Pinar

2011-06-01

Polymer-stabilization of blue phase liquid crystal systems within a host polymer network are reported, which enables ultrafast switching flexible displays. Our newly developed method to stabilize the blue phase in an existing polymer network (e.g., that of a polymer network liquid crystal; PNLC) has shown wide temperature stability and fast response speeds. Systems where the blue phase is stabilized in an already existing polymer network are attractive candidates for ultrafast LCDs. The technology also promises to be applied to flexible PNLC and/or polymer dispersed liquid crystal (PDLC) displays using plastic substrate such as polyethylene terephthalate (PET).

Polymers for hydrogen infrastructure and vehicle fuel systems :

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

Barth, Rachel Reina; Simmons, Kevin L.; San Marchi, Christopher W.

2013-10-01

This document addresses polymer materials for use in hydrogen service. Section 1 summarizes the applications of polymers in hydrogen infrastructure and vehicle fuel systems and identifies polymers used in these applications. Section 2 reviews the properties of polymer materials exposed to hydrogen and/or high-pressure environments, using information obtained from published, peer-reviewed literature. The effect of high pressure on physical and mechanical properties of polymers is emphasized in this section along with a summary of hydrogen transport through polymers. Section 3 identifies areas in which fuller characterization is needed in order to assess material suitability for hydrogen service.

Nanoparticles as strengthening agents in polymer systems

NASA Astrophysics Data System (ADS)

Shahid, Naureen

2005-11-01

Carboxylate-substituted alumina nanoparticles are produced solvent free using mechanical shear. The general nature of this method has been demonstrated for L-lysine-, stearate, and p-hydroxybenzoate-derived materials. The reaction rate and particle size is controlled by a combination of temperature and shear rate. The nanoparticles are spectroscopically equivalent to those reported from aqueous syntheses, however, the average particle size can be decreased and the particle size distribution narrowed depending on the reaction conditions. Lysine and p-hydroxybenzoato alumoxanes have been introduced in carbon fiber reinforced epoxide resin composites. Different preparation conditions have been studied to obtain composite with enhanced performances that are ideal for the motor sports and aerospace industries. A new composite material has been fabricated utilizing surface-modified carboxylate alumoxane nanoparticles and the biodegradable polymer poly(propylene fumarate)/poly(propylene fumarate)-diacrylate (PPF/PPF-DA). For this study, composites were prepared using various functional groups including: a surfactant alumoxane to enhance nanoparticle dispersion into the polymer; an activated-alumoxane to enhance nanoparticle interaction with the polymer matrix; a mixed alumoxane containing both activated and surfactant groups. Nanocomposites prepared with all types of alumoxane, as well as blank polymer resin and unmodified boehmite, underwent mechanical testing and were characterized by SEM and microprobe analysis. A nanocomposite composed of mixed alumoxane nanoparticles dispersed in PPF/PPF-DA exhibited increased flexural modulus compared to polymer resin alone, and a significant enhancement over both the activated and surfacted alumoxanes. Boric acid is used as the cross-linking agent in oil well drilling industry even though the efficacy of the borate ion, [B(OH)4]- , as a cross-linking agent is poor. The reaction product of boric acid and the polysaccharide guaran (the major component of guar gum) has been investigated by 11B NMR spectroscopy. By comparison with the 11B NMR of boric acid and phenyl boronic acid complexes of 1,2-diols [HOCMe2CMe2OH, cis-C6H 10(OH)2, trans-C6H10(OH) 2, o-C6H4(OH)2], 1,3-diols (neol-H2), monosaccharides (L-fucose, mannose and galactose) and disaccharides (celloboise and sucrose) it is found that the guaran polymer is cross-linked via a borate complex of two 1,2-diols both forming chelate 5-membered ring cycles, this contrasts with previous proposals. (Abstract shortened by UMI.)

Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial.

PubMed

Auvichayapat, Paradee; Prapochanung, Montira; Tunkamnerdthai, Oratai; Sripanidkulchai, Bung-orn; Auvichayapat, Narong; Thinkhamrop, Bandit; Kunhasura, Soontorn; Wongpratoom, Srisuda; Sinawat, Supat; Hongprapas, Pranithi

2008-02-27

This study was undertaken to investigate the effects of green tea on weight reduction in obese Thais. A randomized, controlled trial involving 60 obese subjects (body mass index, BMI > 25 kg/m2) was conducted. All subjects consumed a Thai diet containing 3 meals (8373.6 kJ/day) for 12 weeks, prepared by the Nutritional Unit at Srinagarind Hospital. The diet contained 65% carbohydrates, 15% protein, and 20% fat. Body weight, BMI, body composition, resting energy expenditure, and substrate oxidation were measured at baseline, and during weeks 4, 8, and 12 of the study. Serum levels of leptin and urine VMA were measured at baseline and during the 12th week. Differences over time and between the treatments (green tea or placebo) over time were determined using two-factor ANOVA with repeated measures. In comparing the two groups, differences in weight loss were 2.70, 5.10, and 3.3 kg during the 4th, 8th, and 12th weeks of the study, respectively. At the 8th and 12th weeks of the study, body weight loss was significantly different (P < 0.05). At the 8th week, the difference in resting energy expenditure was 183.38 kJ/day (P < 0.001), the difference in the respiratory quotient was 0.02 (P < 0.05), and no significant differences existed in satiety score, food intake, or physical activity. Urine VMA was significantly different in the 12th week of the study (P < 0.05). We conclude that green tea can reduce body weight in obese Thai subjects by increasing energy expenditure and fat oxidation.

Electrochemical performance of a solvent-free hybrid ceramic-polymer electrolyte based on Li7La3Zr2O12 in P(EO)15LiTFSI

NASA Astrophysics Data System (ADS)

Keller, Marlou; Appetecchi, Giovanni Battista; Kim, Guk-Tae; Sharova, Varvara; Schneider, Meike; Schuhmacher, Jörg; Roters, Andreas; Passerini, Stefano

2017-06-01

The preparation of hybrid ceramic-polymer electrolytes, consisting of 70 wt% of Li+ cation conducting Li7La3Zr2O12 (LLZO) and 30 wt% of P(EO)15LiTFSI polymer electrolyte, through a solvent-free procedure is reported. The LLZO-P(EO)15LiTFSI hybrid electrolytes exhibit remarkable improvement in terms of flexibility and processability with respect to pure LLZO ceramic electrolytes. The physicochemical and electrochemical investigation shows the effect of LLZO annealing, resulting in ion conduction gain. However, slow charge transfer at the ceramic-polymer interface is also observed especially at higher temperatures. Nevertheless, improved compatibility with lithium metal anodes and good Li stripping/plating behavior are exhibited by the LLZO-P(EO)15LiTFSI hybrid electrolytes with respect to P(EO)15LiTFSI.

Group 10 Metal Benzene-1,2-dithiolate Derivatives in the Synthesis of Coordination Polymers Containing Potassium Countercations.

PubMed

Castillo, Oscar; Delgado, Esther; Gómez-García, Carlos J; Hernández, Diego; Hernández, Elisa; Martín, Avelino; Martínez, José I; Zamora, Félix

2017-10-02

The use of theoretical calculations has allowed us to predict the coordination behavior of dithiolene [M(SC 6 H 4 S) 2 ] 2- (M = Ni, Pd, Pt) entities, giving rise to the first organometallic polymers {[K 2 (μ-H 2 O) 2 ][Ni(SC 6 H 4 S) 2 ]} n and {[K 2 (μ-H 2 O) 2 (thf)] 2 [K 2 (μ-H 2 O) 2 (thf) 2 ][Pd 3 (SC 6 H 4 S) 6 ]} n by one-pot reactions of the corresponding d 10 metal salts, 1,2-benzenedithiolene, and KOH. The polymers are based on σ,π interactions between potassium atoms and [M(SC 6 H 4 S) 2 ] 2- (M = Ni, Pd) entities. In contrast, only σ interactions are observed when the analogous platinum derivative is used instead, yielding the coordination polymer {[K 2 (μ-thf) 2 ][Pt(SC 6 H 4 S) 2 ]} n .

Performance comparison of the 4th generation Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA on the EVOLIS™ automated system versus Abbott ARCHITECT HIV Ag/Ab Combo, Ortho Anti-HIV 1+2 EIA on Vitros ECi and Siemens HIV-1/O/2 enhanced on Advia Centaur.

PubMed

Mitchell, Elizabeth O; Stewart, Greg; Bajzik, Olivier; Ferret, Mathieu; Bentsen, Christopher; Shriver, M Kathleen

2013-12-01

A multisite study was conducted to evaluate the performance of the Bio-Rad 4th generation GS HIV Combo Ag/Ab EIA versus Abbott 4th generation ARCHITECT HIV Ag/Ab Combo. The performance of two 3rd generation EIAs, Ortho Diagnostics Anti-HIV 1+2 EIA and Siemens HIV 1/O/2 was also evaluated. Study objective was comparison of analytical HIV-1 p24 antigen detection, sensitivity in HIV-1 seroconversion panels, specificity in blood donors and two HIV false reactive panels. Analytical sensitivity was evaluated with International HIV-1 p24 antigen standards, the AFFSAPS (pg/mL) and WHO 90/636 (IU/mL) standards; sensitivity in acute infection was compared on 55 seroconversion samples, and specificity was evaluated on 1000 negative blood donors and two false reactive panels. GS HIV Combo Ag/Ab demonstrated better analytical HIV antigen sensitivity compared to ARCHITECT HIV Ag/Ab Combo: 0.41 IU/mL versus 1.2 IU/mL (WHO) and 12.7 pg/mL versus 20.1 pg/mL (AFSSAPS); GS HIV Combo Ag/Ab EIA also demonstrated slightly better specificity compared to ARCHITECT HIV Ag/Ab Combo (100% versus 99.7%). The 4th generation HIV Combo tests detected seroconversion 7-11 days earlier than the 3rd generation HIV antibody only EIAs. Both 4th generation immunoassays demonstrated excellent performance in sensitivity, with the reduction of the serological window period (7-11 days earlier detection than the 3rd generation HIV tests). However, GS HIV Combo Ag/Ab demonstrated improved HIV antigen analytical sensitivity and slightly better specificity when compared to ARCHITECT HIV Ag/Ab Combo assay, with higher positive predictive values (PPV) for low prevalence populations. Copyright © 2013 Elsevier B.V. All rights reserved.

Polymers for Drug Delivery Systems

PubMed Central

Liechty, William B.; Kryscio, David R.; Slaughter, Brandon V.; Peppas, Nicholas A.

2012-01-01

Polymers have played an integral role in the advancement of drug delivery technology by providing controlled release of therapeutic agents in constant doses over long periods, cyclic dosage, and tunable release of both hydrophilic and hydrophobic drugs. From early beginnings using off-the-shelf materials, the field has grown tremendously, driven in part by the innovations of chemical engineers. Modern advances in drug delivery are now predicated upon the rational design of polymers tailored for specific cargo and engineered to exert distinct biological functions. In this review, we highlight the fundamental drug delivery systems and their mathematical foundations and discuss the physiological barriers to drug delivery. We review the origins and applications of stimuli-responsive polymer systems and polymer therapeutics such as polymer-protein and polymer-drug conjugates. The latest developments in polymers capable of molecular recognition or directing intracellular delivery are surveyed to illustrate areas of research advancing the frontiers of drug delivery. PMID:22432577

12 CFR 271.3 - Published information.

Code of Federal Regulations, 2014 CFR

2014-01-01

... from the Publications Services of the Federal Reserve Board, 20th Street and Constitution Avenue, N.W... Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) FEDERAL OPEN MARKET COMMITTEE RULES REGARDING AVAILABILITY OF INFORMATION § 271.3 Published information. (a) Federal Register. The Committee publishes in the...

12 CFR 271.3 - Published information.

Code of Federal Regulations, 2012 CFR

2012-01-01

... from the Publications Services of the Federal Reserve Board, 20th Street and Constitution Avenue, N.W... Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) FEDERAL OPEN MARKET COMMITTEE RULES REGARDING AVAILABILITY OF INFORMATION § 271.3 Published information. (a) Federal Register. The Committee publishes in the...

NASA Tech Briefs, December 2001. Volume 25, No. 12

NASA Technical Reports Server (NTRS)

2001-01-01

Topics include: special coverage section on sensors, and sections on electronic components and systems, software, materials, mechanics, information sciences, book and reports, and a special section of Motion Control Tech Briefs. It also contains a section celebrating the 25th anniversary of the publication.

Triple Header Annual Workshop Proceedings (12th, Sarasota, Florida, April 25-29, 1993).

ERIC Educational Resources Information Center

American Probation and Parole Association, Lexington, KY.

The family and juvenile court system in the United States is overwhelmed with the number of court cases involving the incarceration of young people. The proceedings of this conference, the goal of which was to find alternatives to incarceration and improve efficiency of the juvenile court system, are summaries of the following 22 presentations:…

IEEE Workshop on Real-Time Operating Systems (8th) Held in Atlanta, Georgia on 15-17 May 1991

DTIC Science & Technology

1992-01-01

and sug- posiur, pages 259-169. !988. gestions in earlier drafts of this paper. [12] L. Sha. J. Lehoczky, and R. Rajkumar. Solutions for some...Telecomunicacion, * j Ciudad Universitaria , E-28040 Madrid, Spain, jpuente@dit.upm.es, Tel:(34-1)3367342, Fax: (34-1)5432077. I Donner, Marc, IBM Research, P.O...Telecomunicacion Ciudad Universitaria E-28040 Madrid SPANJE Dear Juan, Enclosed please find the Final Report on the 17th IFAC/IFIP Workshop on Real Time Programming

Idiopathic and normal lateral lumbar curves: muscle effects interpreted by 12th rib length asymmetry with pathomechanic implications for lumbar idiopathic scoliosis.

PubMed

Grivas, Theodoros B; Burwell, R Geoffrey; Kechagias, Vasileios; Mazioti, Christina; Fountas, Apostolos; Kolovou, Dimitra; Christodoulou, Evangelos

2016-01-01

The historical view of scoliosis as a primary rotation deformity led to debate about the pathomechanic role of paravertebral muscles; particularly multifidus, thought by some to be scoliogenic, counteracting, uncertain, or unimportant. Here, we address lateral lumbar curves (LLC) and suggest a pathomechanic role for quadrates lumborum, (QL) in the light of a new finding, namely of 12th rib bilateral length asymmetry associated with idiopathic and small non-scoliosis LLC. Group 1: The postero-anterior spinal radiographs of 14 children (girls 9, boys 5) aged 9-18, median age 13 years, with right lumbar idiopathic scoliosis (IS) and right LLC less that 10°, were studied. The mean Cobb angle was 12° (range 5-22°). Group 2: In 28 children (girls 17, boys 11) with straight spines, postero-anterior spinal radiographs were evaluated similarly to the children with the LLC, aged 8-17, median age 13 years. The ratio of the right/left 12th rib lengths and it's reliability was calculated. The difference of the ratio between the two groups was tested; and the correlation between the ratio and the Cobb angle estimated. Statistical analysis was done using the SPSS package. The ratio's reliability study showed intra-observer +/-0,036 and the inter-observer error +/-0,042 respectively in terms of 95 % confidence limit of the error of measurements. The 12th rib was longer on the side of the curve convexity in 12 children with LLC and equal in two patients with lumbar scoliosis. The 12th rib ratios of the children with lumbar curve were statistically significantly greater than in those with straight spines. The correlation of the 12th rib ratio with Cobb angle was statistically significant. The 12th thoracic vertebrae show no axial rotation (or minimal) in the LLC and no rotation in the straight spine group. It is not possible, at present, to determine whether the 12th convex rib lengthening is congenitally lengthened, induced mechanically, or both. Several small muscles are attached to the 12th ribs. We focus attention here on the largest of these muscles namely, QL. It has attachments to the pelvis, 12th ribs and transverse processes of lumbar vertebrae as origins and as insertions. Given increased muscle activity on the lumbar curve convexity and similar to the interpretations of earlier workers outlined above, we suggest two hypotheses, relatively increased activity of the right QL muscle causes the LLCs (first hypothesis); or counteracts the lumbar curvature as part of the body's attempt to compensate for the curvature (second hypothesis). These hypotheses may be tested by electrical stimulation studies of QL muscles in subjects with lumbar IS by revealing respectively curve worsening or correction. We suggest that one mechanism leading to relatively increased length of the right 12 ribs is mechanotransduction in accordance with Wolff's and Pauwels Laws.

Science Proficiency and Course Taking in High School: The Relationship of Science Course-Taking Patterns to Increases in Science Proficiency between 8th and 12th Grades.

ERIC Educational Resources Information Center

Madigan, Timothy

This analysis uses data on science achievement and transcript reports of science course taking patterns of students from the National Education Longitudinal Study of 1988 (NELS:88) to estimate the relationship between science course taking and the change in science proficiency levels between 8th and 12th grades. It also explores the extent to…

Idaho National Laboratory Quarterly Occurrence Analysis 4th Quarter FY 2016

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

Mitchell, Lisbeth Ann

This report is published quarterly by the Idaho National Laboratory (INL) Quality and Performance Management Organization. The Department of Energy (DOE) Occurrence Reporting and Processing System, as prescribed in DOE Order 232.2, “Occurrence Reporting and Processing of Operations Information,” requires a quarterly analysis of events, both reportable and not reportable, for the previous 12 months. This report is the analysis of 84 reportable events (29 from the 4th quarter fiscal year 2016 and 55 from the prior three reporting quarters), as well as 39 other issue reports (including events found to be not reportable and Significant Category A and Bmore » conditions) identified at INL during the past 12 months (two from this quarter and 37 from the prior three quarters).« less

Effect of attractive interactions between polymers on the effective force acting between colloids immersed in a polymer system: Analytic liquid-state theory.

PubMed

Chervanyov, A I

2016-12-28

By making use of the polymer reference interaction site model, we analytically study the effect of attractive interactions between polymers on the effective forces acting between colloids immersed in a polymer system. The performed theoretical analysis has no restrictions with respect to the polymer density and relative sizes of the colloids and polymers. The polymer mediated (PM) potential acting between colloids is shown to significantly depend on the strength and range of the polymer-polymer interactions. In the nano-particle limit, where the colloid radius is much smaller than the polymer gyration radius, the presence of attractive polymer-polymer interactions causes only quantitative changes to the PM potential. In the opposite limit of relatively large colloids, the polymer-polymer interactions revert the sign of the total effective force acting between colloids so that this force becomes attractive at sufficiently large polymer densities. With the objective to study an intricate interplay between the attractive PM forces and steric repulsion in different polymer density regimes, we calculate the second virial coefficient B of the total effective potential acting between colloids. The dependence of B on the polymer density is discussed in detail, revealing several novel features of the PM interactions caused by the presence of attractive polymer-polymer interactions.

Polymer/Solvent and Polymer/Polymer Interaction Studies

DTIC Science & Technology

1980-09-01

temperatures up to 450 12 before serious degradation occurs. They have good hydrolytic stability, good solvent resistance, and excellent thermo- oxidative ...Concentration for Sorption in Glassy PVC 5 Temperature Dependence of the Flory-Huggins Interaction Parameters 115 6 Solubility of Dichloromethane in Polysulfone...116 7 Test of Applicability of the Langmuir Equation for Describing Sorption Data 117 8 Temperature Dependence of the Specific Volume of an Amorphous

Sagittal and transversal plane deformity in thoracic scoliosis.

PubMed

Kotwicki, Tomasz

2002-01-01

The aim of the study was to assess the sagittal and transversal plane deformity of the spine in thoracic scoliosis by the mean of 3-D radiographic analysis. 46 patients admitted for surgery for thoracic idiopathic scoliosis underwent preoperative radiographic assessment. All patients presented the same pattern of the coronal plane deformity: single right thoracic curve (Lenke 1, King 3). Neither lumbar nor proximal thoracic structural curve were present. The Cobb angle varied from 41gamma to 77 gamma (mean 55,4 gamma +/- 8,6 gamma). Long cassette standing antero-posterior and lateral radiographs were analysed. Three-dimensional reconstruction with Rachis 91TM software was performed for each pair of radiographs. The following parameters were assessed: sagittal thoracic Cobb angle (Th4-Th12), upper thoracic kyphosis angle (Th5-Th8), lower thoracic kyphosis angle (Th9-Th12), superior and inferior hemi-curve sagittal angles, lumbar lordosis, sacral slope, sacral incidence, vertebral plate index, segmental vertebral axial rotation throughout the thoracic and lumbar spine. Results showed great variability of parameters assessed. The non-harmonious distribution of kyphosis was demonstrated in the thoracic spine. Local Th9-Th12 hypokyphosis and adjacent local Th5-Th8 hyperkyphosis constitute the most typical sagittal pathologies. So called normokyphotic curves were composed of one hyperkyphotic and one hypokyphotic zone. Th1-Th4 segment revealed two patterns of segmental rotation distribution: a purely compensatory curve with no vertebral axial rotation or a rotated curve presenting the morphology intermediate between Lenke 1 and Lenke 2 types (or King 3 and King 5). curves presenting the same coronal plane deformity differ in their morphology assessed in the two other planes; global thoracic kyphosis angle is a misleading parameter because it covers hypo- and hyperkyphotic zones; local distal thoracic (Th9-Th12) hypokyphosis is present in idiopathic thoracic scoliosis.

Early human pregnancy serum cytokine levels predict autoimmunity in offspring.

PubMed

Lindehammer, Sabina Resic; Björck, Sara; Lynch, Kristian; Brundin, Charlotte; Marsal, Karel; Agardh, Daniel; Fex, Malin

2011-09-01

It is generally believed that pregnancy is mediated by a Th2 response, which includes cytokines that promote placental growth and are involved in inducing tolerance to the foetus. If the balance between Th1/and Th2-mediated cytokines is disrupted, systemic and local changes could predispose the foetus to future disease. Therefore, a shift in the Th1/Th2 balance during pregnancy, possibly caused by underlying environmental factors, could be associated with post-partum autoimmune disease in the offspring. Based on this presumption, we used celiac disease as a model to investigate whether autoimmunity is triggered in the foetus during early pregnancy, observed as changes in the mother's cytokine profile. Ten cytokines were measured by electro-chemi-luminescent multiplex ELISA in serum samples obtained from mothers during early pregnancy. Cases included women with children who had developed verified celiac disease before the age of 5, who were compared with other women as matched controls. We observed that 7 out of 10 cytokine levels were significantly increased in our case mothers when compared to controls. Five of these belonged to what is generally known as a Th1-mediated response (TNFα, IFNγ, IL-2, IL-1β and IL-12) and two were Th2 cytokines (IL-13 and IL-10). However, the IL-10 cytokine is known to have features from both arms of the immune system. These results were confirmed in a logistic regression model where five out of the initial seven cytokines remained. This study suggests that increase in Th1 serum cytokines may be associated with celiac disease in offspring.

Transfer of immunoglobulins and antibodies in the hen's egg

PubMed Central

Kramer, T. T.; Cho, H. C.

1970-01-01

The presence of immunoglobulins and antibodies were investigated in the fertile hen's egg during embryogenesis. The egg yolk, egg albumin, amniotic and allantoic fluids, chick embryo serum and intestinal contents were examined for the presence of immunoglobulin and level of antibodies. Immunoglobulin G was not detected in fresh egg albumin, but appeared in the albumin from the 4th day of embryogenesis and persisted through the 16th day. The antibody profile of egg albumin during embryogenesis attained two peaks, which were separated by a trough on the 8th day of embryogenesis. The immunoelectrophoretic pattern of albumin IgG was different from that of egg yolk IgG. The IgG of chick embryo serum was of γ2 mobility on the 12th day of incubation and shifted gradually to the full range of γ1 and γ2 mobilities on the 20th day of incubation. Egg-transmitted antibodies appeared on the 12th day of incubation and attained peak values on the 16th day of incubation. Moderate antibody levels were detected in the amniotic and allantoic fluids from the 12th to the 18th days of incubation. ImagesFIG. 1FIG. 2FIG. 4FIG. 5FIG. 7 PMID:4098593

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

Chew, K. W.; Chen, S. S.; Pang, W. L.

The effects of Lithium triflate salt (LiCF{sub 3}SO{sub 3}), on the poly (methyl methacrylate)(PMMA)-based solid polymer electrolytes plasticized with propylene carbonate (PC) solvated in Tetrahydrofuran (THF) have been studied through a.c impedance spectroscopy and infrared spectroscopy. Lithium triflate was incorporated into the predetermined PMMA/PC system that has the highest value of ionic conductivity. In current investigations, four combination systems: Pure PMMA, (PMMA+PC) systems, (PMMA+LiCF{sub 3}SO{sub 3}) and (PMMA+PC+LiCF{sub 3}SO{sub 3}) systems were prepared using the solution cast method. Solutions were stirred for numerous hours to obtain a homogenous solution before it is poured into the petri dishes under ambient temperaturemore » to form the solid electrolyte thin film. The films were then removed from petri discs and transferred into the dessicator for further drying prior to the different tests. From the characterization done through the a.c impedance spectroscopy, the highest room temperature ionic conductivity in the pure PMMA sample, (PMMA+PC) system and (PMMA+LiCF{sub 3}SO{sub 3}) system is 2.83x10{sup -12} Scm{sup -1}, 4.39x10{sup -11} Scm{sup -1} and 3.93x10{sup -6} Scm{sup -1} respectively. The conductivity for (PMMA+PC+LiCF{sub 3}SO{sub 3}) system was obtained with the 30 wt% of lithium triflate, which is 2.48x10{sup -5} Scm{sup -1}. Infrared spectroscopy shows that complexation occurred between the polymer and the plasticizer, and the polymer and plasticizer and salt. The interactions have been studied in the C=O band, C-O-C band and the O-CH{sub 3} band.« less

Multitemporal field-based plant height estimation using 3D point clouds generated from small unmanned aerial systems high-resolution imagery

NASA Astrophysics Data System (ADS)

Malambo, L.; Popescu, S. C.; Murray, S. C.; Putman, E.; Pugh, N. A.; Horne, D. W.; Richardson, G.; Sheridan, R.; Rooney, W. L.; Avant, R.; Vidrine, M.; McCutchen, B.; Baltensperger, D.; Bishop, M.

2018-02-01

Plant breeders and agronomists are increasingly interested in repeated plant height measurements over large experimental fields to study critical aspects of plant physiology, genetics and environmental conditions during plant growth. However, collecting such measurements using commonly used manual field measurements is inefficient. 3D point clouds generated from unmanned aerial systems (UAS) images using Structure from Motion (SfM) techniques offer a new option for efficiently deriving in-field crop height data. This study evaluated UAS/SfM for multitemporal 3D crop modelling and developed and assessed a methodology for estimating plant height data from point clouds generated using SfM. High-resolution images in visible spectrum were collected weekly across 12 dates from April (planting) to July (harvest) 2016 over 288 maize (Zea mays L.) and 460 sorghum (Sorghum bicolor L.) plots using a DJI Phantom 3 Professional UAS. The study compared SfM point clouds with terrestrial lidar (TLS) at two dates to evaluate the ability of SfM point clouds to accurately capture ground surfaces and crop canopies, both of which are critical for plant height estimation. Extended plant height comparisons were carried out between SfM plant height (the 90th, 95th, 99th percentiles and maximum height) per plot and field plant height measurements at six dates throughout the growing season to test the repeatability and consistency of SfM estimates. High correlations were observed between SfM and TLS data (R2 = 0.88-0.97, RMSE = 0.01-0.02 m and R2 = 0.60-0.77 RMSE = 0.12-0.16 m for the ground surface and canopy comparison, respectively). Extended height comparisons also showed strong correlations (R2 = 0.42-0.91, RMSE = 0.11-0.19 m for maize and R2 = 0.61-0.85, RMSE = 0.12-0.24 m for sorghum). In general, the 90th, 95th and 99th percentile height metrics had higher correlations to field measurements than the maximum metric though differences among them were not statistically significant. The accuracy of SfM plant height estimates fluctuated over the growing period, likely impacted by the changing reflectance regime due to plant development. Overall, these results show a potential path to reducing laborious manual height measurement and enhancing plant research programs through UAS and SfM.

Effects of Saccharomyces boulardii on neonatal hyperbilirubinemia: a randomized controlled trial.

PubMed

Serce, Ozge; Gursoy, Tugba; Ovali, Fahri; Karatekin, Guner

2015-02-01

Since probiotics modulate intestinal functions and enterohepatic circulation; they might have an effect on neonatal hyperbilirubinemia treatment. The objective of this study was to investigate the efficacy of Saccharomyces boulardii supplementation on hyperbilirubinemia. A prospective, double-blind, placebo controlled trial was performed on 35 to 42 gestational weeks' neonates. They were randomized either to receive feeding supplementation with S. boulardii 125 mg every 12 hours or placebo during phototherapy. Serum bilirubin levels were measured at 0, 24th, 48th, 72nd, and 96th hour of phototherapy. A total of 119 infants (61 in the control group and 58 in the study group) were enrolled. The duration of phototherapy (2 [1-3] vs. 2 [1-3], p: 0.22) was not different between groups. The levels of bilirubin during phototherapy ([24th hour; 14.1 {12.8-15.7} vs. 13.5 {12.4-14.9}, p: 0.085]; [48th hour; 14.1 {12-15.3} vs. 13.4 {12.4-14.5}, p: 0.41]; [72nd hour; 13.9 {12.2-15.6} vs. 13.5 {12.5-14.5}, p: 0.41]; [96th hour; 14.7 {11.4-15.5} vs. 13.4 {10.7-14.1}, p: 0.24]) or the duration of rebound phototherapy (1 [1-1] vs. 1.5 [1-2], p: 0.40) were lower in the study group than in the controls, but none of the values were statistically significant. S. boulardii did not influence the clinical course of hyperbilirubinemia significantly. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Development of pH Sensitive Nanoparticles for Intestinal Drug Delivery Using Chemically Modified Guar Gum Co-Polymer.

PubMed

Varma, Vegesna Naga Sravan Kumar; Shivakumar, Hosakote Gurumalappa; Balamuralidhara, Veerna; Navya, Manne; Hani, Umme

2016-01-01

The aim of the research work was to chemically modify guargum (GG) as a pH sensitive co-polymer and formulating intestinal targeting ESO nanoparticles (NPs) using the synthesized co-polymer. Poly acrylamide-grafted-guar gum (PAAm-g-GG) co-polymer was synthesized by free radical polymerization. Chemical modification of PAAm-g-GG by alkaline hydrolysis results in formation of a pH-sensitive co-polymer. The effect of GG and acryl amide (AAm) on grafting was studied. Esomeprazole magnesium (ESO) loaded pH sensitive NPs were prepared by nano-emulsification polymer crosslinking method and characterized. Sixteen formulations were prepared and the concentration of process variables wasvaried to obtain nanoparticles of 200-600 nm. The NPs were found to be homogenous in size distribution. The encapsulation efficiency and drug loading ranged from 33.2% to 50.1% and 12.2% to 17.2% respectively. Particle size, encapsulation efficiency and drug loading increasedalong with co-polymer concentration. In-vitro release studies at pH 1.2 for 2 h, followed by pH 6.8 showed that environment pH significantly affected the drug release. SEM has shown that NPsare spherical with smooth surface. The pH sensitive PAAm-g-GGNPs resisted the initial release of the drug from the drug loaded NPs in acidic pH and delayed the release process to a longer period in alkaline environment.

Development of pH Sensitive Nanoparticles for Intestinal Drug Delivery Using Chemically Modified Guar Gum Co-Polymer

PubMed Central

Varma, Vegesna Naga Sravan Kumar; Shivakumar, Hosakote Gurumalappa; Balamuralidhara, Veerna; Navya, Manne; Hani, Umme

2016-01-01

The aim of the research work was to chemically modify guargum (GG) as a pH sensitive co-polymer and formulating intestinal targeting ESO nanoparticles (NPs) using the synthesized co-polymer. Poly acrylamide-grafted-guar gum (PAAm-g-GG) co-polymer was synthesized by free radical polymerization. Chemical modification of PAAm-g-GG by alkaline hydrolysis results in formation of a pH-sensitive co-polymer. The effect of GG and acryl amide (AAm) on grafting was studied. Esomeprazole magnesium (ESO) loaded pH sensitive NPs were prepared by nano-emulsification polymer crosslinking method and characterized. Sixteen formulations were prepared and the concentration of process variables wasvaried to obtain nanoparticles of 200-600 nm. The NPs were found to be homogenous in size distribution. The encapsulation efficiency and drug loading ranged from 33.2% to 50.1% and 12.2% to 17.2% respectively. Particle size, encapsulation efficiency and drug loading increasedalong with co-polymer concentration. In-vitro release studies at pH 1.2 for 2 h, followed by pH 6.8 showed that environment pH significantly affected the drug release. SEM has shown that NPsare spherical with smooth surface. The pH sensitive PAAm-g-GGNPs resisted the initial release of the drug from the drug loaded NPs in acidic pH and delayed the release process to a longer period in alkaline environment. PMID:27610149

Effect of ginsenoside Rg3 on tyrosine hydroxylase and related mechanisms in the forced swimming-induced fatigue rats.

PubMed

Xu, Yuxia; Zhang, Peng; Wang, Chu; Shan, Ye; Wang, Dandan; Qian, Fenglei; Sun, Mengwei; Zhu, Cuiqing

2013-10-28

Ginsenoside Rg3 has shown multiple pharmacological activities and been considered as one of the most promising approaches for fatigue treatment. However, little is known about the cellular and molecular mechanisms of Rg3 on anti-fatigue and the effect of Rg3 on dopaminergic system has not been reported yet. The major aim of this study is to investigate the effect of Rg3 on TH expression and the related biochemical parameters, such as PKAα, ERK1/2, Akt and α-synuclein in brain of fatigue rats. Weight-loaded forced swimming was performed to establish an animal model of fatigue. Rg3 (10mg/kg, 50mg/kg and 100mg/kg) was intragastrically administrated before swimming. The effect of Rg3 on the expression and phosphorylation of TH and TH-related proteins in fatigue rats or in SH-SY5Y cells was assessed with western blotting. HPLC was used to examine the level of DA and DOPAC in the fatigue rats tissues. TH and phosphorylated TH were decreased in different brain regions of which ventral midbrain were less affected in weight-loaded forced swimming rats. Pretreatment with Rg3 significantly suppressed fatigue-induced decrease expression of TH and TH phosphorylation. Also treatment with Rg3 reversed the decrease expression of PKAα as well as the phosphorylation of ERK1/2 and Akt which were induced by weight-loaded forced swimming. Moreover, weight-loaded swimming could induce the increase expression of α-synuclein in hippocampus and midbrain, while suppressed α-synuclein expression in striatum and prefrontal cortex. Furthermore, Rg3 could induce the increase of TH expression and phosphorylation which was accompanied with elevated expression and phosphorylation of related kinase proteins in vitro, while the inhibitors of kinase proteins could suppress these effects of Rg3. In addition, HPLC results showed that Rg3 could reverse the weight-loaded swimming-induced increase of DOPAC/DA ratio. Our data suggest that fatigue can induce the decrease of DA which might partially result from the change of TH expression and phosphorylation, and Rg3 can reverse these fatigue-induced changes. The underling mechanisms may include the activity changes of PKAα, ERK1/2, Akt and α-synuclein. © 2013 Published by Elsevier Ireland Ltd.

Polymers for 3D Printing and Customized Additive Manufacturing.

PubMed

Ligon, Samuel Clark; Liska, Robert; Stampfl, Jürgen; Gurr, Matthias; Mülhaupt, Rolf

2017-08-09

Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting. The range of polymers used in AM encompasses thermoplastics, thermosets, elastomers, hydrogels, functional polymers, polymer blends, composites, and biological systems. Aspects of polymer design, additives, and processing parameters as they relate to enhancing build speed and improving accuracy, functionality, surface finish, stability, mechanical properties, and porosity are addressed. Selected applications demonstrate how polymer-based AM is being exploited in lightweight engineering, architecture, food processing, optics, energy technology, dentistry, drug delivery, and personalized medicine. Unparalleled by metals and ceramics, polymer-based AM plays a key role in the emerging AM of advanced multifunctional and multimaterial systems including living biological systems as well as life-like synthetic systems.

Polymers for 3D Printing and Customized Additive Manufacturing

PubMed Central

2017-01-01

Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting. The range of polymers used in AM encompasses thermoplastics, thermosets, elastomers, hydrogels, functional polymers, polymer blends, composites, and biological systems. Aspects of polymer design, additives, and processing parameters as they relate to enhancing build speed and improving accuracy, functionality, surface finish, stability, mechanical properties, and porosity are addressed. Selected applications demonstrate how polymer-based AM is being exploited in lightweight engineering, architecture, food processing, optics, energy technology, dentistry, drug delivery, and personalized medicine. Unparalleled by metals and ceramics, polymer-based AM plays a key role in the emerging AM of advanced multifunctional and multimaterial systems including living biological systems as well as life-like synthetic systems. PMID:28756658

Fractionation of poly(methacrylic acid) and poly(vinyl pyridine) in aqueous and organic mobile phases by multidetector thermal field-flow fractionation.

PubMed

Greyling, Guilaume; Pasch, Harald

2017-08-25

Multidetector thermal field-flow fractionation (ThFFF) is shown to be a versatile characterisation platform that can be used to characterise hydrophilic polymers in a variety of organic and aqueous solutions with various ionic strengths. It is demonstrated that ThFFF fractionates isotactic and syndiotactic poly(methacrylic acid) (PMAA) as well as poly(2-vinyl pyridine) (P2VP) and poly(4-vinyl pyridine) (P4VP) according to microstructure in organic solvents and that the ionic strength of the mobile phase has no influence on the retention behaviour of the polymers. With regard to aqueous solutions, it is shown that, despite the weak retention, isotactic and syndiotactic PMAA show different retention behaviours which can qualitatively be attributed to microstructure. Additionally, it is shown that the ionic strength of the mobile phase has a significant influence on the thermal diffusion of polyelectrolytes in aqueous solutions and that the addition of an electrolyte is essential to achieve a microstructure-based separation of P2VP and P4VP in aqueous solutions. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultra-broad range organic solid-state laser from a dye-doped holographic grating quasi-waveguide configuration

NASA Astrophysics Data System (ADS)

Liu, Minghuan; Liu, Yonggang; Peng, Zenghui; Mu, Quanquan; Cao, Zhaoliang; Lu, Xinghai; Ma, Ji; Xuan, Li

2017-08-01

This paper reports the ultra-broad 149.1 nm lasing emission from 573.2 to 722.3 nm using a simple [4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran] (DCM)-doped holographic polymer-dispersed liquid crystal (HPDLC) grating quasi-waveguide configuration by varying the grating period. The lasing emission beams show s-polarization property. The quasi-waveguide structure, which contained the cover glass, the DCM-doped HPDLC grating, the semiconducting polymer film poly[-methoxy-5-(2‧-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV), and the substrate were confirmed to decrease lasing threshold and broaden lasing wavelength. The operational lifetime of the device is 240 000 pulses, which corresponds to an overall laser duration of more than 6 h at a repetition rate of 10 Hz. In addition, the dual-wavelength lasing range from the 8th and 9th order is over 40 nm. The electrical tunability of the dual-wavelength lasing emission is over 1 nm. The experimental results facilitated the decreased lasing threshold and broadened lasing wavelength range of organic solid-state lasers.

H sub 3 PMo sub 12 O sub 40 -doped polyacetylene as a catalyst for ethyl alcohol conversion

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

Pozniczek, J.; Bielanski, A.; Kulszewicz-Bajer, I.

1991-12-01

A new and highly efficient catalyst was obtained by exploiting the unique ability of polyacetylene to incorporate heteropolyanions (HPA) of the Keggin type via oxidative doping. 12-Molybdophosphoric acid, 20.8 wt%, was introduced into the polymer. A uniform distribution of HPA over the cross section of the polymer film was found. However, the concentration of HPA seemed to be higher at the surface of the polymer fibers than in their bulk. The conversion of ethyl alcohol was used as a catalytic test reaction. The catalyst exhibited both acid-base activity (formation of ethylene and diethyl ether) as well as redox activity (formationmore » of acetaldehyde). The acid-base activity was 10 times higher than that of unsupported H{sub 3}PMo{sub 12}O{sub 40}, and the redox activity was about 40 times higher.« less

Stable trifluorostyrene containing compounds grafted to base polymers, and their use as polymer electrolyte membranes

DOEpatents

Yang, Zhen-Yu; Roelofs, Mark Gerrit

2010-11-09

A fluorinated ion exchange polymer prepared by grafting at least one grafting monomer on to at least one base polymer, wherein the grafting monomer comprises structure 1a or 1b: wherein Z comprises S, SO.sub.2, or POR wherein R comprises a linear or branched perfluoroalkyl group of 1 to 14 carbon atoms optionally containing oxygen or chlorine, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 12 carbon atoms or a substituted aryl group of 6 to 12 carbon atoms; RF comprises a linear or branched perfluoroalkene group of 1 to 20 carbon atoms, optionally containing oxygen or chlorine; Q is chosen from F, --OM, NH.sub.2, --N(M)SO.sub.2R.sup.2.sub.F, and C(M)(SO.sub.2R.sup.2.sub.F).sub.2, wherein M comprises H, an alkali cation, or ammonium; R.sup.2.sub.F groups comprises alkyl of 1 to 14 carbon atoms which may optionally include ether oxygens or aryl of 6 to 12 carbon atoms where the alkyl or aryl groups may be perfluorinated or partially fluorinated; and n is 1 or 2 for 1a, and n is 1, 2, or 3 for 1b. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.

Stable trifluorostyrene containing compounds grafted to base polymers, and their use as polymer electrolyte membranes

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

Yang, Zhen-Yu; Roelofs, Mark Gerrit

2010-11-09

A fluorinated ion exchange polymer prepared by grafting at least one grafting monomer on to at least one base polymer, wherein the grafting monomer comprises structure 1a or 1b: wherein Z comprises S, SO.sub.2, or POR wherein R comprises a linear or branched perfluoroalkyl group of 1 to 14 carbon atoms optionally containing oxygen or chlorine, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 12 carbon atoms or a substituted aryl group of 6 to 12 carbon atoms; RF comprises a linear or branched perfluoroalkene group of 1 to 20 carbon atoms, optionallymore » containing oxygen or chlorine; Q is chosen from F, --OM, NH.sub.2, --N(M)SO.sub.2R.sup.2.sub.F, and C(M)(SO.sub.2R.sup.2.sub.F).sub.2, wherein M comprises H, an alkali cation, or ammonium; R.sup.2.sub.F groups comprises alkyl of 1 to 14 carbon atoms which may optionally include ether oxygens or aryl of 6 to 12 carbon atoms where the alkyl or aryl groups may be perfluorinated or partially fluorinated; and n is 1 or 2 for 1a, and n is 1, 2, or 3 for 1b. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.« less

Administration of IL-1β to the 4th ventricle causes anorexia that is blocked by agouti-related peptide and that coincides with activation of tyrosine-hydroxylase neurons in the nucleus of the solitary tract

PubMed Central

DeBoer, Mark D.; Scarlett, Jarrad M.; Levasseur, Peter R.; Grant, Wilmon F.; Marks, Daniel L.

2010-01-01

Inflammation-associated cachexia is associated with multiple chronic diseases and involves activation of appetite regulating centers in the arcuate nucleus of the hypothalamus (ARH). The nucleus of the solitary tract (NTS) in the brainstem has also been implicated as an important nucleus involved in appetite regulation. We set out to determine whether the NTS may be involved in inflammation-associated anorexia by injecting IL-1β into the 4th ventricle and assessing food intake and NTS neuronal activation. Injection of IL-1β produced a decrease in food intake at 3 and 12 h after injection which was ameliorated at the 12 h time point by a sub-threshold dose of agouti-related peptide (AgRP). Investigation into neuron types in the NTS revealed that IL-1β injection was associated with an increase in c-Fos activity in NTS neurons expressing tyrosine hydroxylase (TH). Additionally, injection of IL-1β into the 4th ventricle did not produce c-Fos activation of neurons expressing pro-opiomelanocortin (POMC) in the ARH, cells known to be involved in producing anorexia in response to systemic inflammation. Double-label in situ hybridization revealed that TH neurons did not express IL-1 receptor I (IL1-RI) transcript, demonstrating that c-Fos activation of TH neurons in this setting was not via direct stimulation of IL-1β on TH neurons themselves. We conclude that IL-1β injection into the 4th ventricle produces anorexia and is accompanied by an increase in activation in TH neurons in the NTS. This provides evidence that the brainstem may be an important mediator of anorexia in the setting of inflammation. PMID:19028534

Synthesis, structure, and catalytic performance in cyclooctene epoxidation of a molybdenum oxide/bipyridine hybrid material: {[MoO3(bipy)][MoO3(H2O)]}n.

PubMed

Abrantes, Marta; Amarante, Tatiana R; Antunes, Margarida M; Gago, Sandra; Paz, Filipe A Almeida; Margiolaki, Irene; Rodrigues, Alírio E; Pillinger, Martyn; Valente, Anabela A; Gonçalves, Isabel S

2010-08-02

The reaction of [MoO(2)Cl(2)(bipy)] (1) (bipy = 2,2'-bipyridine) with water in a Teflon-lined stainless steel autoclave (100 degrees C, 19 h), in an open reflux system with oil bath heating (12 h) or in a microwave synthesis system (120 degrees C, 4 h), gave the molybdenum oxide/bipyridine hybrid material {[MoO(3)(bipy)][MoO(3)(H(2)O)]}(n) (2) as a microcrystalline powder in yields of 72-92%. The crystal structure of 2 determined from synchrotron X-ray powder diffraction data is composed of two distinct neutral one-dimensional polymers: an organic-inorganic polymer, [MoO(3)(bipy)](n), and a purely inorganic chain, [MoO(3)(H(2)O)](n), which are interconnected by O-H...O hydrogen bonding interactions. Compound 2 is a moderately active, stable, and selective catalyst for the epoxidation of cis-cyclooctene at 55 degrees C with tert-butylhydroperoxide (tBuOOH, 5.5 M in decane or 70% aqueous) as the oxidant. Biphasic solid-liquid or triphasic solid-organic-aqueous mixtures are formed, and 1,2-epoxycyclooctane is the only reaction product. When n-hexane is employed as a cosolvent and tBuOOH(decane) is the oxidant, the catalytic reaction is heterogeneous in nature, and the solid catalyst can be recycled and reused without a loss of activity. For comparison, the catalytic performance of the precursor 1 was also investigated. The IR spectra of solids recovered after catalysis indicate that 1 transforms into the organic-inorganic polymer [MoO(3)(bipy)] when the oxidant is tBuOOH(decane) and compound 2 when the oxidant is 70% aqueous tBuOOH.

A chemiluminescence biosensor based on the adsorption recognition function between Fe3O4@SiO2@GO polymers and DNA for ultrasensitive detection of DNA.

PubMed

Sun, Yuanling; Li, Jianbo; Wang, Yanhui; Ding, Chaofan; Lin, Yanna; Sun, Weiyan; Luo, Chuannan

2017-05-05

In this work, a chemiluminescence (CL) biosensor was prepared for ultrasensitive determination of deoxyribonucleic acid (DNA) based on the adsorption recognition function between core-shell Fe 3 O 4 @SiO 2 - graphene oxide (Fe 3 O 4 @SiO 2 @GO) polymers and DNA. The Fe 3 O 4 @SiO 2 @GO polymers were composed by GO and magnetite nanoparticles. And the core-shell polymers were confirmed by Scanning Electron Microscope (SEM), X-Ray Powder Diffraction (XRD) and Fourier Transform Infrared (FTIR). Then Fe 3 O 4 @SiO 2 @GO was modified by DNA. Based on the principle of complementary base, Fe 3 O 4 @SiO 2 @GO-DNA was introduced to the CL system and the selectivity, sensitivity of DNA detection was significantly improved. The adsorption properties of Fe 3 O 4 @SiO 2 @GO to DNA were researched through the adsorption equilibrium, adsorption kinetic and thermodynamics. Under optimized CL conditions, DNA could be assayed with the linear concentration range of 5.0×10 -12 -2.5×10 -11 mol/L. The detection limit was 1.7×10 -12 mol/L (3δ) and the relative standard deviation (RSD) was 3.1%. The biosensor was finally used for the determination of DNA in laboratory samples and recoveries ranged from 99% to 103%. The satisfactory results revealed the potential application of Fe 3 O 4 @SiO 2 @GO-DNA-CL biosensor in the diagnosis and the treatment of human genetic diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal gelation and tissue adhesion of biomimetic hydrogels

PubMed Central

Burke, Sean A; Ritter-Jones, Marsha; Lee, Bruce P; Messersmith, Phillip B

2008-01-01

Marine and freshwater mussels are notorious foulers of natural and manmade surfaces, secreting specialized protein adhesives for rapid and durable attachment to wet substrates. Given the strong and water-resistant nature of mussel adhesive proteins, significant potential exists for mimicking their adhesive characteristics in bioinspired synthetic polymer materials. An important component of these proteins is L-3,4-dihydroxylphenylalanine (DOPA), an amino acid believed to contribute to mussel glue solidification through oxidation and crosslinking reactions. Synthetic polymers containing DOPA residues have previously been shown to crosslink into hydrogels upon the introduction of oxidizing reagents. Here we introduce a strategy for stimuli responsive gel formation of mussel adhesive protein mimetic polymers. Lipid vesicles with a bilayer melting transition of 37 °C were designed from a mixture of dipalmitoyl and dimyristoyl phosphatidylcholines and exploited for the release of a sequestered oxidizing reagent upon heating from ambient to physiologic temperature. Colorimetric studies indicated that sodium-periodate-loaded liposomes released their cargo at the phase transition temperature, and when used in conjunction with a DOPA-functionalized poly(ethylene glycol) polymer gave rise to rapid solidification of a crosslinked polymer hydrogel. The tissue adhesive properties of this biomimetic system were determined by in situ thermal gelation of liposome/polymer hydrogel between two porcine dermal tissue surfaces. Bond strength measurements showed that the bond formed by the adhesive hydrogel (mean = 35.1 kPa, SD = 12.5 kPa, n = 11) was several times stronger than a fibrin glue control tested under the same conditions. The results suggest a possible use of this biomimetic strategy for repair of soft tissues. PMID:18458476

Cloud point phenomena for POE-type nonionic surfactants in a model room temperature ionic liquid.

PubMed

Inoue, Tohru; Misono, Takeshi

2008-10-15

The cloud point phenomenon has been investigated for the solutions of polyoxyethylene (POE)-type nonionic surfactants (C(12)E(5), C(12)E(6), C(12)E(7), C(10)E(6), and C(14)E(6)) in 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), a typical room temperature ionic liquid (RTIL). The cloud point, T(c), increases with the elongation of the POE chain, while decreases with the increase in the hydrocarbon chain length. This demonstrates that the solvophilicity/solvophobicity of the surfactants in RTIL comes from POE chain/hydrocarbon chain. When compared with an aqueous system, the chain length dependence of T(c) is larger for the RTIL system regarding both POE and hydrocarbon chains; in particular, hydrocarbon chain length affects T(c) much more strongly in the RTIL system than in equivalent aqueous systems. In a similar fashion to the much-studied aqueous systems, the micellar growth is also observed in this RTIL solvent as the temperature approaches T(c). The cloud point curves have been analyzed using a Flory-Huggins-type model based on phase separation in polymer solutions.

Leptospira Immunoglobulin-Like Protein B (LigB) Binds to Both the C-Terminal 23 Amino Acids of Fibrinogen αC Domain and Factor XIII: Insight into the Mechanism of LigB-Mediated Blockage of Fibrinogen α Chain Cross-Linking.

PubMed

Hsieh, Ching-Lin; Chang, Eric; Tseng, Andrew; Ptak, Christopher; Wu, Li-Chen; Su, Chun-Li; McDonough, Sean P; Lin, Yi-Pin; Chang, Yung-Fu

2016-09-01

The coagulation system provides a primitive but effective defense against hemorrhage. Soluble fibrinogen (Fg) monomers, composed of α, β and γ chains, are recruited to provide structural support for the formation of a hemostatic plug. Fg binds to platelets and is processed into a cross-linked fibrin polymer by the enzymatic clotting factors, thrombin and Factor XIII (FXIII). The newly formed fibrin-platelet clot can act as barrier to protect against pathogens from entering the bloodstream. Further, injuries caused by bacterial infections can be confined to the initial wound site. Many pathogenic bacteria have Fg-binding adhesins that can circumvent the coagulation pathway and allow the bacteria to sidestep containment. Fg expression is upregulated during lung infection providing an attachment surface for bacteria with the ability to produce Fg-binding adhesins. Fg binding by leptospira might play a crucial factor in Leptospira-associated pulmonary hemorrhage, the main factor contributing to lethality in severe cases of leptospirosis. The 12th domain of Leptospira immunoglobulin-like protein B (LigB12), a leptospiral adhesin, interacts with the C-terminus of FgαC (FgαCC). In this study, the binding site for LigB12 was mapped to the final 23 amino acids at the C-terminal end of FgαCC (FgαCC8). The association of FgαCC8 with LigB12 (ELISA, KD = 0.76 μM; SPR, KD = 0.96 μM) was reduced by mutations of both charged residues (R608, R611 and H614 from FgαCC8; D1061 from LigB12) and hydrophobic residues (I613 from FgαCC8; F1054 and A1065 from LigB12). Additionally, LigB12 bound strongly to FXIII and also inhibited fibrin formation, suggesting that LigB can disrupt coagulation by suppressing FXIII activity. Here, the detailed binding mechanism of a leptospiral adhesin to a host hemostatic factor is characterized for the first time and should provide better insight into the pathogenesis of leptospirosis.

Leptospira Immunoglobulin-Like Protein B (LigB) Binds to Both the C-Terminal 23 Amino Acids of Fibrinogen αC Domain and Factor XIII: Insight into the Mechanism of LigB-Mediated Blockage of Fibrinogen α Chain Cross-Linking

PubMed Central

Hsieh, Ching-Lin; Chang, Eric; Tseng, Andrew; Ptak, Christopher; Wu, Li-Chen; Su, Chun-Li; McDonough, Sean P.; Lin, Yi-Pin; Chang, Yung-Fu

2016-01-01

The coagulation system provides a primitive but effective defense against hemorrhage. Soluble fibrinogen (Fg) monomers, composed of α, β and γ chains, are recruited to provide structural support for the formation of a hemostatic plug. Fg binds to platelets and is processed into a cross-linked fibrin polymer by the enzymatic clotting factors, thrombin and Factor XIII (FXIII). The newly formed fibrin-platelet clot can act as barrier to protect against pathogens from entering the bloodstream. Further, injuries caused by bacterial infections can be confined to the initial wound site. Many pathogenic bacteria have Fg-binding adhesins that can circumvent the coagulation pathway and allow the bacteria to sidestep containment. Fg expression is upregulated during lung infection providing an attachment surface for bacteria with the ability to produce Fg-binding adhesins. Fg binding by leptospira might play a crucial factor in Leptospira-associated pulmonary hemorrhage, the main factor contributing to lethality in severe cases of leptospirosis. The 12th domain of Leptospira immunoglobulin-like protein B (LigB12), a leptospiral adhesin, interacts with the C-terminus of FgαC (FgαCC). In this study, the binding site for LigB12 was mapped to the final 23 amino acids at the C-terminal end of FgαCC (FgαCC8). The association of FgαCC8 with LigB12 (ELISA, KD = 0.76 μM; SPR, KD = 0.96 μM) was reduced by mutations of both charged residues (R608, R611 and H614 from FgαCC8; D1061 from LigB12) and hydrophobic residues (I613 from FgαCC8; F1054 and A1065 from LigB12). Additionally, LigB12 bound strongly to FXIII and also inhibited fibrin formation, suggesting that LigB can disrupt coagulation by suppressing FXIII activity. Here, the detailed binding mechanism of a leptospiral adhesin to a host hemostatic factor is characterized for the first time and should provide better insight into the pathogenesis of leptospirosis. PMID:27622634

Solid State Ionic Materials - Proceedings of the 4th Asian Conference on Solid State Ionics

NASA Astrophysics Data System (ADS)

Chowdari, B. V. R.; Yahaya, M.; Talib, I. A.; Salleh, M. M.

1994-07-01

The Table of Contents for the full book PDF is as follows: * Preface * I. INVITED PAPERS * Diffusion of Cations and Anions in Solid Electrolytes * Silver Ion Conductors in the Crystalline State * NMR Studies of Superionic Conductors * Hall Effect and Thermoelectric Power in High Tc Hg-Ba-Ca-Cu-O Ceramics * Solid Electrolyte Materials Prepared by Sol-Gel Chemistry * Preparation of Proton-Conducting Gel Films and their Application to Electrochromic Devices * Thin Film Fuel Cells * Zirconia based Solid Oxide Ion Conductors in Solid Oxide Fuel Cells * The Influence of Anion Substitution on Some Phosphate-based Ion Conducting Glasses * Lithium Intercalation in Carbon Electrodes and its Relevance in Rocking Chair Batteries * Chemical Sensors using Proton Conducting Ceramics * NMR/NQR Studies of Y-Ba-Cu-O Superconductors * Silver Molybdate Glasses and Battery Systems * New Highly Conducting Polymer Ionics and their Application in Electrochemical Devices * Study of Li Electrokinetics on Oligomeric Electrolytes using Microelectrodes * Calculation of Conductivity for Mixed-Phase Electrolytes PEO-MX-Immiscible Additive by Means of Effective Medium Theory * II. CONTRIBUTED PAPERS * Phase Relationship and Electrical Conductivity of Sr-V-O System with Vanadium Suboxide * Amorphous Li+ Ionic Conductors in Li2SO4-Li2O-P2O5 System * Fast Ion Transport in KCl-Al2O3 Composites * The Effect of the Second Phase Precipitation on the Ionic Conductivity of Zr0.85Mg0.15O1.85 * Conductivity Measurements and Phase Relationships in CaCl2-CaHCl Solid Electrolyte * Relationships Between Crystal Structure and Sodium Ion Conductivity in Na7Fe4(AsO4)6 and Na3Al2(AsO4)3 * Electrical Conductivity and Solubility Limit of Ti4+ Ion in Na1+x TiyZr2-ySixP3-xO12 System * Study on Sodium Fast Ion Conductors of Na1+3xAlxTi2-xSi2xP3-2xO12 System * Influences of Zirconia on the Properties of β''-Alumina Ceramics * Decay of Luminescence from Cr3+ Ions in β-Alumina * Lithium Ion Conductivity in the Li4XO4-Li2SO4 (X=Si, Ge, Ti) Systems * A DSC and Conductivity Study of the Influence of Cesium Ion on the Beta-Alpha Transition in Silver Iodide * Phase Diagrams, Stoichiometries and Properties of Bi4V2O11:M2+ Solid Electrolytes * Physical Properties of Electrodeposited Silver Chromotungstate * Pseudopotential Study of Bonding in the Superionic Material AgI: The Effect of Statistical Distribution of Mobile Ions * Cubic Phase Dominant Region in Submicron BaTiO3 Particles * The Crystallization of CoZr Amorphous Alloys via Electrical Resistivity * Cation Ratio Related Properties of Synthetic Mg/Al Layered Double Hydroxide and it's Nanocomposite * DC Conductivity of Nano-Particles of Silver Iodide * Effect of Anomalous Diffusion on Quasielastic Scattering in Superionic Conductors * Computer Simulation Study of Conductivity Enhancement in Superionic-Insulator Composites * Dynamics of Superionic Silver and Copper Iodide Salt Melts * Influence of Dopant Salt AgI, Glass Modifier Ag2O and Glass Formers (SeO3 + MoO3) on Electrical Conductivity in Quaternary Glassy System * Fast Ion Conductivity in the Presence of Competitive Network Formers * Role of Alkali Ions in Borate Glasses * Inelastic Light Scattering in Cadmium Borate Glasses * Investigation on Transport Properties of Mixed Glass System 0.75 [0.75AgI:0.25AgCl]. 0.25[Ag2O:CrO3] * Conduction Mechanism in Lithium Tellurite Glasses * Optimized Silver Tungstoarsenate Glass Electrolyte * Stabilized Superfine Zirconia Powder Prepared by Sol-Gel Process * Study of New PAN-based Electrolytes * Electrical and Thermal Characterization of PVA based Polymer Electrolytes * Conductive Electroactive Polymers: Versatile Solid State Ionic Materials * The Role of Ag2O Addition on the Superconducting Properties of Y-124 Compound * Absorption Spectra Studies of the C60 Films on Transition Metal Film Substrates * Effect of Alumina Dispersal on the Conductivity and Crystallite Size of Polymer Electrolyte * New Mixed Galss-Polymer Solid Electrolytes * The Sputtered La0.5Sr0.5MnO3-Yttria Stabilized Zirconia Composite Electrode in Solid Oxide Fuel Cells * A Solid Electrochemical Ferro Sensor for Molten Matte * SnO2-based Sensor for H2S Monitoring-Electrical Conductivity Measurements and Device Testing * Humidity Sensor using Potassium Tungsten Bronze Synthesized from Peroxo-Polytungstic Acid * Study on Li/LiClO4/V6O13 Test Cells * Fabrication and Characterisation of Some Solid Electrolyte Cells Containing CuI and Silver Oxysalts * Solid State Battery of Proton Conducting Sodium Thiosulphate Pentahydrate * Low Temperature Synthesis of LiMn2O4 for Secondary Lithium Batteries * Effect of Different Cathode Active Materials on Battery Performance with Silver Molybdate Electrolyte Partially Substituted with Zinc Oxide * Fabrication and Characterization of Electrochemical Cells based on Silver Molybdoarsenate and Silver Tungstoarsenate Glass Electrolytes * Lorentz Force Dependence of Dissipation in a Granular Superconductor * Late Entry (Invited paper) * Simultaneous Voltammetry and Spectroscopy of Polyaniline in Propylene Carbonate * Author Index * Tentative List of Participants

System for diffusing light from an optical fiber or light guide

DOEpatents

Maitland, Duncan J [Pleasant Hill, CA; Wilson, Thomas S [San Leandro, CA; Benett, William J [Livermore, CA; Small, IV, Ward [

2008-06-10

A system for diffusing light from an optical fiber wherein the optical fiber is coupled to a light source, comprising forming a polymer element adapted to be connected to the optical fiber and incorporating a scattering element with the polymer element wherein the scattering element diffuses the light from the polymer element. The apparatus of the present invention comprises a polymer element operatively connected to the optical fiber and a scattering element operatively connected with the shape polymer element that diffuses the light from the polymer element.

Polymer in a pore: Effect of confinement on the free energy barrier

NASA Astrophysics Data System (ADS)

Kumar, Sanjiv; Kumar, Sanjay

2018-06-01

We investigate the transfer of a polymer chain from cis- side to trans- side through two types of pores: cone-shaped channel and flat-channel. Using the exact enumeration technique, we obtain the free energy landscapes of a polymer chain for such systems. We have also calculated the free-energy barrier of a polymer chain attached to the edge of the pore. The model system allows us to calculate the force required to pull polymer from the pore and stall-force to confine polymer within the pore.

Inhalation Toxicology. 12. Comparison of Toxicity Rankings of Six Polymers by Lethality and by Incapacitation in Rats

DTIC Science & Technology

1991-12-01

DOT/FAA/AM-91/17 Inhalation Toxicology : XII. Comparison of Toxicity Office of Aviation Medicine Rankings of Six Polymers by \\Vashington, D.C. 20591...Subtitil $I Report Oat. INHALATION TOXICOLOGY : XII. COMPARISON OF TOXICITY. December 1991 RANKINGS OF SIX POLYMERS BY LETHALITY AND BY 6. Performing...the ts (min) at LC50s, the polymers were grouped into III & V (10.5, 11.0); I, II & V1 (14.1-15.0); and IV (19.5). The two toxicological end points

Smart and functional polymer materials for smart and functional microfluidic instruments

NASA Astrophysics Data System (ADS)

Gray, Bonnie L.

2014-04-01

As microfluidic systems evolve from "chip-in-the-lab" to true portable lab-on-a-chip (LoC) or lab-in-a-package (LiP) microinstrumentation, there is a need for increasingly miniaturized sensors, actuators, and integration/interconnect technologies with high levels of functionality and self-direction. Furthermore, as microfluidic instruments are increasingly realized in polymer-based rather than glass- or silicon- based platforms, there is a need to realize these highly functional components in materials that are polymer-compatible. Polymers that are altered to possess basic functionality, and even higher-functioning "smart" polymer materials, may help to realize high-functioning and selfdirecting portable microinstrumentation. Stimuli-responsive hydrogels have been recognized for over a decade as beneficial to the development of smart microfluidics systems and instrumentation. In addition, functional materials such as conductive and magnetic composite polymers are being increasingly employed to push microfluidics systems to greater degrees of functionality, portability, and/or flexibility for wearable/implantable systems. Functional and smart polymer materials can be employed to realize electrodes, electronic routing, heaters, mixers, valves, pumps, sensors, and interconnect structures in polymer-based microfluidic systems. Stimuli for such materials can be located on-chip or in a small package, thus greatly increasing the degree of portability and the potential for mechanical flexibility of such systems. This paper will examine the application of functional polymer materials to the development of high-functioning microfluidics instruments with a goal towards self-direction.

The role of schoolmates' smoking and non-smoking in adolescents' smoking transitions: a longitudinal study.

PubMed

Bricker, Jonathan B; Andersen, M Robyn; Rajan, K Bharat; Sarason, Irwin G; Peterson, Arthur V

2007-10-01

The first longitudinal investigation of the extent to which same-age and older schoolmates' smoking and non-smoking are associated with adolescents' smoking transitions during three grade intervals. Same-age and older schoolmates' smoking and non-smoking were assessed when adolescents were at grades 5 (age 10), 7 (age 12) and 9 (age 14). Adolescents' smoking transitions were assessed at three grade intervals: 5th-7th (age 10-12), 7th-9th (age 12-14) and 9th-12th (age 14-17). Forty Washington State school districts. Smoking questionnaire data were gathered on a cohort of adolescents (n = 4354 for same-age schoolmate analysis; n = 1833 for older schoolmate analysis) that was 49% female and 91% Caucasian. No significant evidence that same-age schoolmates' smoking or non-smoking was associated with any of the adolescent smoking transitions at any of the three grade intervals. In contrast, the probability that each older schoolmate's smoking was associated with the adolescent making the transition to trying smoking was 1% (95% CI: 0.4%, 1.5%) and with the transition from trying to monthly smoking was also 1% (95% CI: 0.2%, 2.0%) during the 7th-9th grade (age 12-14) interval. Moreover, each older schoolmate's non-smoking was associated with a 1.001-1.006 (all P < 0.05) relative risk of an adolescent not trying smoking or escalating from trying to monthly smoking at several grade intervals. Interventions should perhaps focus on the influence of both smoking and non-smoking older schoolmates during late childhood and early adolescence.

Einstein X-ray observations of M101

NASA Technical Reports Server (NTRS)

Trinchieri, G.; Fabbiano, G.; Romaine, S.

1990-01-01

The Einstein X-ray observations of the face-on spiral galaxy M101 are presented. The global X-ray luminosity L(x) of M101 is about 1.2 x 10 to the 40th ergs/s for D = 7.2 Mpc, consistent with the expected X-ray luminosity of normal spiral galaxies of its optical magnitude. The X-ray emission is mostly due to very luminous individual sources, with L(x) greater than 10 to the 38th ergs/s each, most likely very massive accreting binary systems. The data suggest a deficiency of sources in the luminosity range of L(x) from about 10 to the 37th to about 10 to the 38th ergs/s, which would indicate that the luminosity distribution of the X-ray sources in M101 might be different from that of M31 or M33.

Incorporation of additives into polymers

DOEpatents

McCleskey, T. Mark; Yates, Matthew Z.

2003-07-29

There has been invented a method for incorporating additives into polymers comprising: (a) forming an aqueous or alcohol-based colloidal system of the polymer; (b) emulsifying the colloidal system with a compressed fluid; and (c) contacting the colloidal polymer with the additive in the presence of the compressed fluid. The colloidal polymer can be contacted with the additive by having the additive in the compressed fluid used for emulsification or by adding the additive to the colloidal system before or after emulsification with the compressed fluid. The invention process can be carried out either as a batch process or as a continuous on-line process.

Student Athletes and Non-Athletes: Do Their Use of and Beliefs about Alcohol and Other Drugs Differ? Special Research Report.

ERIC Educational Resources Information Center

Ringwalt, Chris

This study examined differences in the use of and beliefs about drugs, by high school athletes and non-athletes. Data for the study were derived from a representative sample of 10,259 7th through 12th grade students in North Carolina conducted in the spring of 1987. Data reported in the study were limited to 11th and 12th grade students, who are…

Annual Fuze Conference (44th)

DTIC Science & Technology

2000-04-11

Untitled Document 44th Fuze Conference.html[6/8/ 2017 10:33:34 AM] Files are in Adobe Acrobat 3.0 format. 44th Annual Fuze Conference 11-12 April...United Kingdom Wednesday, April 12, 2000 Untitled Document 44th Fuze Conference.html[6/8/ 2017 10:33:34 AM] Rockwell Collins’ Artillery GPS Engine...cooperation with U.S experts Mitch Stone Texarkana , Texas Day & Zimmermann, Inc. - Lone Star Division We do what we say! þ History and Evolution þ

Situational analysis and future directions of AYUSH: An assessment through 5-year plans of India

PubMed Central

Samal, Janmejaya

2015-01-01

AYUSH is an acronym for Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homeopathy. These are the six indigenous systems of medicine practiced in India. A department called Department of Indian System of medicine was created in March 1995 and renamed to AYUSH in November 2003 with a focus to provide increased attention for the development of these systems. Very recently, in 2014, a separate ministry was created under the union Government of India, which is headed by a minister of state. Planning regarding these systems of medicine was a part of 5-year planning process since 1951. Since then many developments have happened in this sector albeit the system was struggling with a great degree of uncertainty at the time of 1st5-year plan. A progressive path of development could be observed since the first to the 12th5-year plan. It was up to the 7thplan the growth was little sluggish and from 8thplan onward the growth took its pace and several innovative development processes could be observed thereafter. The system is gradually progressing ahead with a vision to be a globally accepted system, as envisaged in 11th5-year plan. Currently, AYUSH system is a part of mainstream health system implemented under National Rural Health Mission (NRHM). NRHM came into play in 2005 but implemented at ground level in 2006 and introduced the scheme of “Mainstreaming of AYUSH and revitalization of local health traditions” to strengthen public health services. This scheme is currently in operation in its second phase, since 1stApril 2012, with the 12th5-year plan. The scheme was primarily brought in to operation with three important objectives; choice of treatment system to the patients, strengthen facility functionally and strengthen the implementation of national health programmes, however, in some places it seems to be a forced medical pluralism owing to a top-down approach by the union government without considerable involvement of the concerned community. In this study, the 5-year planning documents have been reviewed, from the 1stplan to 12thplan, to enable reflection and throw some light into the future directions of AYUSH system. PMID:26649240

Analysis of multimode BDK doped POF gratings for temperature sensing

NASA Astrophysics Data System (ADS)

Luo, Yanhua; Wu, Wenxuan; Wang, Tongxin; Cheng, Xusheng; Zhang, Qijin; Peng, Gang-Ding; Zhu, Bing

2012-10-01

We report a temperature sensor based on a Bragg grating written in a benzil dimethyl ketal (BDK) doped multimode (MM) polymer optical fiber (POF) for the first time to our knowledge. The thermal response was further analyzed in view of theory and experiment. In theory, with the order of the reflected mode increasing from 1st to 60th order, for MM silica fiber Bragg grating (FBG) the temperature sensitivity will increase linearly from 16.2 pm/°C to 17.5 pm/°C, while for MM polymer FBG the temperature sensitivity (absolute value) will increase linearly from -79.5 pm/°C to -104.4 pm/°C. In addition, temperature sensitivity of MM polymer FBG exhibits almost 1 order larger mode order dependence than that of MM silica FBG. In experiment, the Bragg wavelength shift will decline linearly as the temperature rises, contrary to that of MM silica FBG. The temperature sensitivity of MM polymer FBG is ranged from -0.097 nm/°C to -0.111 nm/°C, more than 8 times that of MM silica FBG, showing great potential used as a temperature sensor.

Gelatin-based microcarriers as embryonic stem cell delivery system in bone tissue engineering: an in-vitro study.

PubMed

Tielens, S; Declercq, H; Gorski, T; Lippens, E; Schacht, E; Cornelissen, M

2007-03-01

Mouse embryonic stem cells were cultured on commercially available biodegradable macroporous microcarriers. A culture period of 1-2 weeks was needed to colonize the microcarriers. Embryonic stem cells retained their pluripotency for up to 14 days when cultured in medium supplemented with leukemia inhibitory factor. Replacing this medium by differentiation medium for 2 weeks initiated osteogenic differentiation. Encapsulation of the cell-loaded microcarriers in photopolymerizable polymers (methacrylate-endcapped poly-D,L-lactide-co-caprolactone), triacetin/hydroxyethylmethacrylate (HEMA) as solvent and with/without gelatin as porogen, resulted in a homogeneous distribution of the microcarriers in the polymer. As observed by transmission electron microscopy, viability of the cells was optimal when gelatin was omitted and when using triacetin instead of HEMA.

Single Wall Carbon Nanotube-polymer Solar Cells

NASA Technical Reports Server (NTRS)

Bailey, Sheila G.; Castro, Stephanie L.; Landi, Brian J.; Gennett, Thomas; Raffaelle, Ryne P.

2005-01-01

Investigation of single wall carbon nanotube (SWNT)-polymer solar cells has been conducted towards developing alternative lightweight, flexible devices for space power applications. Photovoltaic devices were constructed with regioregular poly(3-octylthiophene)-(P3OT) and purified, >95% w/w, laser-generated SWNTs. The P3OT composites were deposited on ITO-coated polyethylene terapthalate (PET) and I-V characterization was performed under simulated AM0 illumination. Fabricated devices for the 1.0% w/w SWNT-P3OT composites showed a photoresponse with an open-circuit voltage (V(sub oc)) of 0.98 V and a short-circuit current density (I(sub sc)) of 0.12 mA/sq cm. Optimization of carrier transport within these novel photovoltaic systems is proposed, specifically development of nanostructure-SWNT complexes to enhance exciton dissociation.

Dectin-1 diversifies Aspergillus fumigatus–specific T cell responses by inhibiting T helper type 1 CD4 T cell differentiation

PubMed Central

Hohl, Tobias M.; Collins, Nichole; Leiner, Ingrid; Gallegos, Alena; Saijo, Shinobu; Coward, Jesse W.; Iwakura, Yoichiro

2011-01-01

Pulmonary infection of mice with Aspergillus fumigatus induces concurrent T helper type 1 (Th1) and Th17 responses that depend on Toll-like receptor/MyD88 and Dectin-1, respectively. However, the mechanisms balancing Th1 and Th17 CD4 T cell populations during infection remain incompletely defined. In this study, we show that Dectin-1 deficiency disproportionally increases Th1 responses and decreases Th17 differentiation after A. fumigatus infection. Dectin-1 signaling in A. fumigatus–infected wild-type mice reduces IFN-γ and IL-12p40 expression in the lung, thereby decreasing T-bet expression in responding CD4 T cells and enhancing Th17 responses. Absence of IFN-γ or IL-12p35 in infected mice or T-bet in responding CD4 T cells enhances Th17 differentiation, independent of Dectin-1 expression, in A. fumigatus–infected mice. Transient deletion of monocyte-derived dendritic cells also reduces Th1 and boosts Th17 differentiation of A. fumigatus–specific CD4 T cells. Our findings indicate that Dectin-1–mediated signals alter CD4 T cell responses to fungal infection by decreasing the production of IL-12 and IFN-γ in innate cells, thereby decreasing T-bet expression in A. fumigatus–specific CD4 T cells and enabling Th17 differentiation. PMID:21242294

[Space-time organization of systems of membrane hydrolysis and transport in rat small intestine].

PubMed

Loginov, G I

1977-05-01

Glucose transport by the concentration gradient with the incubation for 90 min in 0.2% glucose and soluble starch solutions was studied in Wistar rats in 5 segments of the small intestine by the "sac turned inside out" method. Serous fluid was completely replaced by a new portion of Ringer's solution every 15 or 30 min. Substrate load synchronized the enterocyte population and stabilized the transport systems. The changes of glucose absorption during the period of about an hour proved to differ in the 5 segments against the background of continuous and interrupted substrate load. These differences were due to the properties of the transported systems autocontrol and the reactivity level of the given enterocyte population. Areas with different reactivity were found to alternate along the intestine. Between the 8th and 16th hour (rats were sacrificed every 2 hours) starch glucose transport fell sharply in the proximal, and, to a lesser extent, in the middle segments. On the contrary, absorption between the 8th and the 12th hour was considerably intensified in the distal segments. The changes of the strach glucose transport during the period of about an hour along the intestine differed. The data obtained are discussed with consideration to the possible role of the undulating processes in the individual enterocyte population and in the small intestine as an integral system.

The Bond Strength of Composite Resin to Dental Casting Alloys Using an Electro-Chemical Tin Plating System.

DTIC Science & Technology

1985-06-01

of Opaque-Adhesive Containing Opaque Powder ..................... 36 Figure 12. Isosit Resin Condensed into Teflon Tubes ..... 37 Figure 13. Device...millimeter long teflon tube was positioned centrally on each specimen. The Isosit body resin was condensed into the tube using the blunt end of a...8217.*. .’-~ ~**.*~.**.**.*~.**.*%~ 37 Figure 12. Isosit Resin Condensed into Teflon Tubes Wy~WW’. WVtTh. .. . - . - S.. * ***’h.).’ *.~’b

The placental immune milieu is characterized by a Th2- and anti-inflammatory transcription profile, regardless of maternal allergy, and associates with neonatal immunity.

PubMed

Abelius, Martina S; Janefjord, Camilla; Ernerudh, Jan; Berg, Göran; Matthiesen, Leif; Duchén, Karel; Nilsson, Lennart J; Jenmalm, Maria C

2015-05-01

How maternal allergy affects the systemic and local immunological environment during pregnancy and the immune development of the offspring is unclear. Expression of 40 genes was quantified by PCR arrays in placenta, peripheral blood mononuclear cells (PBMC), and cord blood mononuclear cells (CBMC) from 7 allergic and 12 non-allergic women and their offspring. Placental gene expression was dominated by a Th2-/anti-inflammatory profile, irrespectively of maternal allergy, as compared to gene expression in PBMC. p35 expression in placenta correlated with fetal Tbx21 (ρ = -0.88, P < 0.001) and IL-5 expression in PBMC with fetal galectin1 (ρ = 0.91, P < 0.001). Increased expression of Th2-associated CCL22 in CBMC preceded allergy development. Gene expression locally and systemically during pregnancy was partly associated with the offspring's gene expression, possibly indicating that the immunological milieu is important for fetal immune development. Maternal allergy was not associated with an enhanced Th2 immunity in placenta or PBMC, while a marked prenatal Th2 skewing, shown as increased CCL22 mRNA expression, might contribute to postnatal allergy development. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The anti-allergic effects of lactic acid bacteria are strain dependent and mediated by effects on both Th1/Th2 cytokine expression and balance.

PubMed

Fujiwara, Daisuke; Inoue, Sayo; Wakabayashi, Hideyuki; Fujii, Toshio

2004-11-01

There is growing interest in the immune-stimulating effect and in particular, the anti-allergic effect, of lactic acid bacteria (LAB). However, no comprehensive studies have been done that compare the immune-stimulating potential of LAB strains. The in vitro immune-stimulating effects on Th1/Th2 balance of more than 100 LAB strains were compared in splenocytes from ovalbumin-sensitized Th2-polarized mice. The in vivo anti-allergic ability of strain KW3110 was studied in the Th2-polarized model by detecting serum IgE concentration, Th1/Th2 cytokine secretion from splenocytes, and the expression of co-stimulatory molecules on macrophages. In vitro studies from Th2-polarized splenocytes, using IL-12 as a Th1 parameter and IL-4 secretion as a Th2 parameter revealed a wide variety of IL-12-inducing and IL-4-repressing activities, depending on the strain of LAB, not depending on the species. However, evaluation of individual strains in vivo revealed that after exposure to Lactobacillus paracasei KW3110 strain, the serum IgE elevation elicited by repeated OVA injection of mice was strongly inhibited. Cytokine secretion from splenocytes 20 weeks after KW3110 administration showed increased IL-12 and decreased IL-4 expression. Both CD40 and B7-1 expression on macrophages was upregulated by administration of KW3110. Improving the consequences of the Th1/Th2 imbalance by administration of LAB was dependent upon the LAB strain rather than the LAB species. Oral KW3110 administration in the mouse allergy model directed the Th1/Th2 balance toward Th1 through the maturation of APCs and inhibition of serum IgE elevation.

Efficient charge injection in p-type polymer field-effect transistors with low-cost molybdenum electrodes through V2O5 interlayer.

PubMed

Baeg, Kang-Jun; Bae, Gwang-Tae; Noh, Yong-Young

2013-06-26

Here we report high-performance polymer OFETs with a low-cost Mo source/drain electrode by efficient charge injection through the formation of a thermally deposited V2O5 thin film interlayer. A thermally deposited V2O5 interlayer is formed between a regioregular poly(3-hexylthiophene) (rr-P3HT) or a p-type polymer semiconductor containing dodecyl-substituted thienylenevinylene (TV) and dodecylthiophene (PC12TV12T) and the Mo source/drain electrode. The P3HT or PC12TV12T OFETs with the bare Mo electrode exhibited lower charge carrier mobility than those with Au owing to a large barrier height for hole injection (0.5-1.0 eV). By forming the V2O5 layer, the P3HT or PC12TV12T OFETs with V2O5 on the Mo electrode exhibited charge carrier mobility comparable to that of a pristine Au electrode. Best P3HT or PC12TV12T OFETs with 5 nm thick V2O5 on Mo electrode show the charge carrier mobility of 0.12 and 0.38 cm(2)/(V s), respectively. Ultraviolet photoelectron spectroscopy results exhibited the work-function of the Mo electrode progressively changed from 4.3 to 4.9 eV with an increase in V2O5 thickness from 0 to 5 nm, respectively. Interestingly, the V2O5-deposited Mo exhibits comparable Rc to Au, which mainly results from the decreased barrier height for hole carrier injection from the low-cost metal electrode to the frontier molecular orbital of the p-type polymer semiconductor after the incorporation of the transition metal oxide hole injection layer, such as V2O5. This enables the development of large-area, low-cost electronics with the Mo electrodes and V2O5 interlayer.

Ultrasound-guided posterior quadratus lumborum block for postoperative pain after laparoscopic cholecystectomy: A randomized controlled double blind study.

PubMed

Ökmen, Korgün; Metin Ökmen, Burcu; Topal, Serra

2018-06-18

Laparoscopic techniques are commonly used in surgical operations of the gallbladder. There are very few regional anesthesia methods used to achieve this goal. We aimed to investigate the effect of ultrasound-guided posterior quadratus lumborum block (QLB), administered bilaterally on pain scores after laparoscopic cholecystectomy operations. Prospective, double blind, randomized controlled clinical trial. Single-institution, tertiary hospital. 60 patients underwent laparoscopic cholecystectomy were included in the study. Patients were randomized to either Group B (intravenous patient-controlled analgesia (IV PCA) + posterior QLB with 0.3 ml/kg 0.25% bupivacaine; n = 30) or Group S (IV PCA + posterior QLB with 0.3 ml/kg 0,9% saline; n = 30). Postoperative pain (during rest) was evaluated at the 30th minute, 2nd, 6th, 12th, and 24th hours using the VAS scores. Postoperative activity pain was also evaluated with VAS at the 2nd, 6th, 12th, and 24th hours. Postoperative 6th, 12th, and 24th hour follow-up results were recorded to identify the quantity of tramadol use. Secondary outcomes included the Ramsey sedation scale (RSS), side effect profile, and additional analgesic use. The VAS scores between the two groups were found to be statistically significantly lower in Group B (p < 0.001). The mean values of the quantity of tramadol use at the 6th, 12th, and 24th hours were found to be statistically significantly lower in Group B (p < 0.001). There was no statistically significant difference in the rate of side effects (p = 0.309) and RSS (p = 0.505) outcomes between the groups. As a result of this study, we think that posterior QLB administered for pain palliation after laparoscopic cholecystectomy operation is an effective analgesia technique. Copyright © 2018 Elsevier Inc. All rights reserved.

The Effect of Classroom Discourse on High School Students' Argumentative Writing Skills

ERIC Educational Resources Information Center

Sineath, Karl D.

2014-01-01

On the writing component of the most recent National Assessment of Educational Progress, 12th grade high school students' scores on argumentative tasks were lower than on tasks that required them to explain or to convey an experience ("National Assessment of Educational Progress," 2011). Similarly, 11th and 12th graders at the research…