Science.gov

Sample records for p2o5 modificados con

  1. The role of P2O5 in silicate melts

    NASA Technical Reports Server (NTRS)

    Ryerson, F. J.; Hess, P. C.

    1980-01-01

    Phase equilibria data in the systems SiO2-P2O5, P2O5-M(x)O(y), and P2O5-M(x)O(y)-SiO2 are employed in conjunction with chromatographic and spectral data to investigate the role of P2O5 in silicate melts. P2O5 depolymerizes pure SiO2 melts by entering the network as a four-fold coordinated cation, but polymerizes melts in which an additional metal cation other than silicon is present. In this complex system P2O5 acts to increase phase separation by further enrichment of the high charge density cations Ti, Fe, Mg, Mn, Ca, in the ferrobasaltic liquid. The dual behavior of P2O5 is explained in a model which requires complexing of phosphate anions and metal cations in the melt. This interaction destroys Si-O-M-O-Si bonds polymerizing the melt. The higher concentration of Si-O-M-O-Si bond complexes in immiscible ferrobasaltic liquids relative to their conjugate immiscible granite liquids explains the partitioning of P2O5 into the ferrobasaltic liquid.

  2. Phase diagram for a portion of the system Ce 2O 3?Na 2O?P 2O 5 rich in P 2O 5

    NASA Astrophysics Data System (ADS)

    Szczygie?, Irena; Znamierowska, Teresa

    1989-10-01

    The phase diagram for a portion of the ternary system Ce 2O 3?Na 2O?P 2O 5 rich in P 2O 5 has been worked out. The durability of two cerium phosphates, CeP 5O 14 and CeP 3O 9, was investigated and the melting point of CeP 5O 14 determined (1064°C congruently). Phase diagrams of the two binary systems CeP 3O 9?CeP 5O 14 and NaCe(PO 3) 4?CeP 5O 14 are presented.

  3. Effects of substituting B2O3 for P2O5 on the structures and properties of V2O5-P2O5 glass systems

    NASA Astrophysics Data System (ADS)

    Han, Kyungseok; Hwang, Chawon; Kim, Donghwan; Gwoo, Donggun; Kim, Taehee; Choi, Wongyu; Kee, Kyungbum; Kim, Jonghwan; Ryu, Bongki

    2012-12-01

    V2O5-B2O3-P2O5 glasses with various compositions were prepared using a normal melt quenching technique, and their characteristics and structural properties were investigated using different techniques. Replacement of P2O5 by B2O3 was found to improve the thermal properties, chemical durability, and room-temperature conductivity. The observed variations in the properties may be correlated with changes in the internal glass network as a result of changes in the chemical composition. Vanadium ions are believed to be present in three possible valence states, namely V3+, V4+, and V5+, and the ratios of these states depend on the glass composition. The observed increases in chemical durability and room-temperature conductivity are assumed to be related to increases in the mean crosslinking density, increases in the number of bridging oxygens, and electron hopping between vanadate ions in different valence states.

  4. Luminescence of phosphorus containing oxide materials: Crystalline SiO2-P and 3P2O5?7SiO2; CaO?P2O5; SrO?P2O5 glasses

    NASA Astrophysics Data System (ADS)

    Trukhin, A. N.; Smits, K.; Jansons, J.; Berzins, D.; Chikvaidze, G.; Griscom, D. L.

    2014-10-01

    Luminescence of phosphate glasses such as CaO?P2O5 and SrO?P2O5 is compared with that of phosphorus doped crystalline ?-quartz and phosphosilicate glass with content 3P2O5?7SiO2. Water & OH groups are found by IR spectra in these materials. The spectrum of luminescence contains many bands in the range 1.5 - 5.5 eV. The luminescence bands in UV range at 4.5-5 eV are similar in those materials. Decay duration in exponential approximation manifests a time constant about 37 ns. Also a component in ?s range was detected. PL band of ?s component is shifted to low energy with respect to that of ˜37 ns component. This shift is about 0.6 eV. It is explained as singlet-triplet splitting of excited state. Below 14 K increase of luminescence kinetics duration in ?s range was observed and it was ascribed to zero magnetic field splitting of triplet excited state of the center. Yellow-red luminescence was induced by irradiation in phosphorus doped crystalline ?-quartz, phosphosilicate glasses. The yellowl uminescence contains two bands at 600 and 740 nm. Their decay is similar under 193 nm laser and may be fitted with the first order fractal kinetics or stretched exponent. Thermally stimulated luminescence contains only band at 600 nm. The 248 nm laser excites luminescence at 740 nm according to intra center process with decay time constant about 4 ms at 9 K. Both type of luminescence UV and yellow were ascribed to different defects containing phosphorus. P-doped ?-quartz sample heated to 550 co become opalescent. Ir spectra related to water & OH groups are changed. Photoluminescence intensity of all three bands, UV (250 nm), yellow (600 nm) and red (740 nm) strongly diminished and disappeared after heating to 660 C°. Radiation induced red luminescence of non-bridging oxygen luminescence center (NBO) appeared in crystal after heat treatment. We had observed a crystalline version of this center (l. Skuja et al, Nuclear Instruments and Methods in Physics Research B 286,159-168 (2012)). Effect of heat treatment explained as sedimentation of phosphorus in some state. Keeping of treated sample at 450-500 C° leads to partial revival of ability to create yellow luminescence center under irradiation.

  5. P-T phase diagram and structural transformations of molten P2O5 under pressure

    NASA Astrophysics Data System (ADS)

    Brazhkin, V. V.; Katayama, Y.; Lyapin, A. G.; Saitoh, H.

    2014-03-01

    The P2O5 compound is an archetypical glass-forming oxide with a record high hygroscopicity, which makes its study extremely difficult. We present the in situ x-ray diffraction study of the pressure-temperature phase diagram of P2O5 and, particularly, of the liquid P2O5 structure under high pressure up to 10 GPa. Additionally, quenching from the melt has been used to extend the melting curve up to 15 GPa. We found that structural transformation in the liquid P2O5 under pressure is unique and includes three stages: first, the disappearance of the intermediate range order of the melt together with a slow increase in the average first-coordination number (P-O and O-P neighbors) up to 4 GPa; second, the "normal" compression almost without structural modification at higher pressures up to 8-9 GPa; and, finally, the abrupt change of the short-range order structure of the liquid with the jumplike increase at 9-10 GPa. The last stage correlates with the melting curve maximum (?1250 °C) at ?10 GPa and can be interpreted as a transformation to the liquid phase with entirely fivefold-coordinated phosphorus and twofold-coordinated oxygen atoms.

  6. Optimization of the thermodynamic properties and phase diagrams of P2O5-containing systems

    NASA Astrophysics Data System (ADS)

    Hudon, Pierre; Jung, In-Ho

    2014-05-01

    P2O5 is an important oxide component in the late stage products of numerous igneous rocks such as granites and pegmatites. Typically, P2O5 combines with CaO and crystallizes in the form of apatite, while in volatile-free conditions, Ca-whitlockite is formed. In spite of their interest, the thermodynamic properties and phase diagrams of P2O5-containg systems are not well known yet. In the case of the pure P2O5 for example, no experimental thermodynamic data are available for the liquid and the O and O' solid phases. As a result, we re-evaluated all the thermodynamic and phase diagram data of the P2O5 unary system [1]. Optimization of the thermodynamic properties and phase diagrams of the binary P2O5 systems was then performed including the Li2O-, Na2O-, MgO-, CaO-, BaO-, MnO-, FeO-, Fe2O3-, ZnO-, Al2O3-, and SiO2-P2O5 [2] systems. All available thermodynamic and phase equilibrium data were simultaneously reproduced in order to obtain a set of model equations for the Gibbs energies of all phases as functions of temperature and composition. In particular, the Gibbs energy of the liquid solution was described using the Modified Quasichemical Model [3-5] implemented in the FactSage software [6]. Thermodynamic modeling of the Li2O-Na2O-K2O-MgO-CaO-FeO-Fe2O3-Al2O3-SiO2 system, which include many granite-forming minerals such as nepheline, leucite, pyroxene, melilite, feldspar and spinel is currently in progress. [1] Jung, I.-H., Hudon, P. (2012) Thermodynamic assessment of P2O5. J. Am. Ceram. Soc., 95 (11), 3665-3672. [2] Rahman, M., Hudon, P. and Jung, I.-H. (2013) A coupled experimental study and thermodynamic modeling of the SiO2-P2O5 system. Metall. Mater. Trans. B, 44 (4), 837-852. [3] Pelton, A.D. and Blander, M. (1984) Computer-assisted analysis of the thermodynamic properties and phase diagrams of slags. Proc. AIME Symp. Metall. Slags Fluxes, TMS-AIME, 281-294. [4] Pelton, A.D. and Blander, M. (1986) Thermodynamic analysis of ordered liquid solutions by a modified quasichemical approach application to silicate slags. Metall. Trans. B, 17, 805-815. [5] A.D. Pelton, S.A. Decterov, G. Eriksson, C. Robelin and Y. Dessureault (2000) The modified quasichemical model - I Binary solutions. Metall. Mater. Trans. B, 31, 651-660. [6] C.W. Bale, P. Chartrand, S.A. Decterov, G. Eriksson, K. Hack, R. Ben Mahfoud, J. Melançon, A.D. Pelton and S. Petersen. (2002) FactSage Thermochemical Software and Databases. Calphad, 26, 189-228.

  7. Gamma-ray irradiation induced bulk photochromism in WO3-P2O5 glass

    NASA Astrophysics Data System (ADS)

    Shen, Wei; Baccaro, Stefania; Cemmi, Alessia; Xu, Xiaoqing; Chen, Guorong

    2015-11-01

    In the present work, photochromism of WO3-P2O5 glass under gamma-ray irradiation was reported. As-prepared glass samples with different WO3 content are all optically transparent in the visible wavelength range thanks to the addition of a small amount of oxidizing couple Sb2O3-NaNO3. The photochromic properties are identified by transmission spectra of the glasses before and after irradiation. The results show that the irradiation induced darkening results from the reduction of W6+ to W5+ or W4+. The existence of WO6 clusters in glasses of high WO3 content is proved by XPS, which is the main reason for the obvious photochromic effects. The WO3-P2O5 glass is a promising candidate in gamma-ray sensitive detector.

  8. Electrical resistivity surface for FeO-Fe2O3-P2O5 glasses

    NASA Technical Reports Server (NTRS)

    Vaughan, J. G.; Kinser, D. L.

    1975-01-01

    The dc electrical properties and microstructure of x(FeO-Fe2O3)-(100-x)P2O5 glasses were investigated up to a maximum of x = 75 mol %. Results indicate that, in general, the minimum resistivity of the glass does not occur at equal Fe(2+) and Fe(3+) concentrations, although for the special case where x = 55 mol % the minimum does occur at Fe(2+)/Fe total = 0.5, as reported by other investigators. Evidence presented shows that the position of the minimum resistivity is a function of total iron content. The minimum shifts to glasses richer in Fe(2+) at higher total iron concentrations.

  9. P2O5-doping in waste glasses: evolution of viscosity and crystallization processes

    NASA Astrophysics Data System (ADS)

    Tarrago, Mariona; Espuñes, Alex; Garcia-Valles, Maite; Martinez, Salvador

    2015-04-01

    Current concern for environmental preservation is the main motive for the study of new, more sustainable materials. Increasing amounts of sewage sludge are produced in wastewater treatment plants over the world every day. This fact represents a major problem for the municipalities and industries due to the volume of waste and also to the contaminant elements it may bear, which require expensive conditions for disposal in landfills. Vitrification is an established technique in the inertization of different types of toxic wastes (such as nuclear wastes and contaminated soils) that has been used successfully for sewage sludge. Glasses of basaltic composition (43.48SiO2-14.00Al2O3-12.86Fe2O3-10.00CaO-9.94MgO-3.27Na2O-1.96K2O-0.17MnO-0.55P2O5-2.48TiO2) are used as a laboratory analogous of wastes such as sewage sludge and galvanic sludge to study the properties of the inertization matrix. This basaltic matrix is doped by adding 1%, 2%, 3%, 4% and 20% of P5O5 in order to cover the compositional range of phosphate in sewage sludge encountered in the literature. In this study, the focus has been placed in the effect of the concentration of phosphate (P2O5) in glass stability, thermal properties and evolution of viscosity with temperature. The dependence of viscosity on temperature and the thermal behaviour of these glasses are critical parameters in the design of their production process. Regarding the compositional limits of the mixture, it has been observed that melt reactivity is much increased when P2O5 content is over 4%, hindering the glass conformation process. Moreover, stanfieldite (calcium and magnesium phosphate) crystallized during glass making when phosphate concentration approached 20%, hence establishing the upper limit for glass stability. Viscosity is also dramatically increased in this range, hence requiring production amends. Differential thermal analysis has provided nucleation and crystallization temperatures of the glasses around 915°C and 1050°C respectively at phosphate contents up to 4%. Subsequent analysis by X-Ray Diffraction has proved that newly formed phases are iron oxides, Ca - Mg silicates and feldspars. Glass transition temperature (Tg; approximately 635°C) obtained by dilatometry remains almost constant until very high phosphate contents; even then, the increase is not large (650°C at 20% P2O5). Hot-Stage microscopy (HSM) has shown the evolution of viscosity with temperature through the analysis of the morphological evolution of cylindrical probes of glass according to German standard DIN 51730. The annealing range (viscosity between 1013.5 and 1012 is reached at temperatures between 600 and 700°C. The temperatures of the lower limit of the working range (viscosity under 103 Pa-s) are between 1325 and 1375°C; decreasing slightly with the addition of P2O5.

  10. Amorphous V2O5-P2O5 as high-voltage cathodes for magnesium batteries.

    PubMed

    Arthur, Timothy S; Kato, Keiko; Germain, Jason; Guo, Jinghua; Glans, Per-Anders; Liu, Yi-Sheng; Holmes, Daniel; Fan, Xudong; Mizuno, Fuminori

    2015-11-01

    A deep investigation of amorphous V2O5-P2O5 powders for magnesium batteries communicates the vital properties to achieving the superior electrochemical performance at a 75?:?25 V2O5?:?P2O5 molar ratio. The manipulation of the inter-layer spacing and amorphization of V2O5 can enhance Mg(2+) diffusion and afford a cathode with high-voltage reversibility. PMID:26360296

  11. Electrical properties and FTIR spectra of ZnO-PbO-P 2O 5 glasses

    NASA Astrophysics Data System (ADS)

    Mansour, E.; El-Damrawi, G.

    2010-04-01

    Glasses of chemical composition xZnO.(60- x)PbO.40P 2O 5 ( x=10-60 mol%) have been prepared and investigated for FTIR, density, molar volume ( V m), and DC conductivity. Both density and molar volume decreases systematically with composition. FTIR analysis indicates that ?30 mol% (PbO and/or ZnO) enters the glass structure as formers. Below and above that concentration a decreasing amount of Pb 2+ (Zn 2+) is incorporated into the network as modifier. The band at 1018-1025 cm -1 can be considered as an indication for the presence of P-O-Pb(Zn) linkages. By introducing ZnO into the glasses, P-O-Pb(Zn) linkages may be formed by opening up P?O bonds of PO 4 tetrahedra. For all glasses the linear dependence of the conductivity indicates an ionic conduction due to Pb 2+ and/or Zn 2+ ions. The increase in activation energy by about 68%, and also the decrease in the conductivity at certain temperature not only attributed to an increase in the covalency of the glass matrix upon replacing PbO by ZnO but also due to an increase in the strain energy because of the decrease in V m of the studied glasses. It is found that the conductivity of ZnO-PbO-P 2O 5 glasses is four orders of magnitude higher than that of ZnO-PbO-B 2O 3 glasses containing the same amount of ZnO measured at the same temperature. In addition, both conductivities decrease with composition which may indicate that the origin of these decreases may be the same regardless the type of the host glass former. The differences in electronegativity and size of Zn 2+ and Pb 2+ divalent ions and the structural changes that will follow in the network govern the conductivity behaviour of Zn-Pb containing glasses.

  12. Effects of CaO/P2O5 ratio on the structure and elastic properties of SiO2-CaO-Na2O-P2O5 bioglasses.

    PubMed

    Lin, Chung-Cherng; Chen, Shih-Fan; Leung, Kak Si; Shen, Pouyan

    2012-02-01

    The evolution of elastic properties and structure upon the change of CaO/P(2)O(5) ratio in SiO(2)-CaO-Na(2)O-P(2)O(5) glasses (45S5-derived and 55S4-derived) at ambient conditions has been studied by using both Brillouin and Raman spectroscopy coupled with X-ray diffraction. Under the same SiO(2)/Na(2)O ratio, it is found that a decrease in CaO/P(2)O(5) molar ratio has caused a more-polymerized silicate network via a net consumption of Q(0), Q(1), and Q(2) species yet enriching in Q(3) and Q(4) species. Brillouin experiments revealed that all the bulk, shear and Young's moduli of the glasses studied increases with the increase of CaO/P(2)O(5) molar ratio. The unexpected variation trend in shear modulus can be correlated to the contribution from cohesion, the less-polymerized phosphate Q species, and density. Compared to the 45S5-derived, the more-polymerized 55S4-deived glass has a lower bulk but slightly higher shear modulus at the given CaO/P(2)O(5) ratio. PMID:22109904

  13. Effect of P2O5 and FetO on the Viscosity and Slag Structure in Steelmaking Slags

    NASA Astrophysics Data System (ADS)

    Wang, Z. J.; Shu, Q. F.; Sridhar, S.; Zhang, M.; Guo, M.; Zhang, Z. T.

    2015-04-01

    The present paper investigates the influence of P2O5 and FetO on the viscosity and structure of steelmaking slags. An understanding of the viscous behavior and structure of FetO-bearing smelting slags is essential to control the dephosphorization in steelmaking process and to efficiently recycle the phosphorus from steelmaking slags. It is found that the viscosity of CaO-SiO2-Al2O3-MgO-FetO-P2O5 slags slightly increases with increasing P2O5 content, while the viscosity decreases with increasing FetO content. The degree of the polymerization of quenched slags, determined from Raman spectra, is found to increase with increasing P2O5 content and decrease with increasing FetO content. It is also noted that the peaks of Raman spectra between 800 and 1200 cm-1 were nearly absent at the FetO content of 22.46 wt pct; whereas according to 29Si MAS-NMR and FTIR analysis, it is clearly seen that the [SiO4]-tetrahedra-related peaks existed even for the same slag. This may confirm that small quantities of extra-framework iron species can absorb the Raman scattering and damp the Raman signal intensity and the presence of FetO in the slag does not necessarily eliminate [SiO4]-tetrahedra.

  14. Proton conduction of MO-P2O5 glasses (M = Zn, Ba) containing a large amount of water

    NASA Astrophysics Data System (ADS)

    Sumi, Hirofumi; Nakano, Yuki; Fujishiro, Yoshinobu; Kasuga, Toshihiro

    2015-07-01

    Zinc and barium phosphate glasses show good proton conductivity at intermediate temperature around 200 °C. Infrared spectra and 1H magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectra proposed that a 30 mol%ZnO-70 mol%P2O5 glass melted at 800 °C has a large amount of 'mobile' protons. The proton conductivity at 250 °C was measured to be 1 × 10-3 S/cm. A H2-air fuel cell using the ZnO-P2O5 glass electrolyte of 1.8 mm in thickness showed the maximum power density of 1.2 mW/cm2 at 200 °C.

  15. Selective Crystallization Behavior of CaO-SiO2-Al2O3-MgO-FetO-P2O5 Steelmaking Slags Modified through P2O5 and Al2O3

    NASA Astrophysics Data System (ADS)

    Wang, Zhanjun; Sun, Yongqi; Sridhar, Seetharaman; Zhang, Mei; Guo, Min; Zhang, Zuotai

    2015-10-01

    In this study, the selective crystallization behavior of synthetic FetO-rich steelmaking slags modified by P2O5 and Al2O3 additions was explored using non-isothermal differential scanning calorimetry, X-ray diffraction, and field emission scanning electron microscopy techniques. Continuous cooling transformation diagrams of Fe-enriched and P-enriched phases were constructed. It was found that P2O5 addition can suppress the crystallization due to the increasing viscosity caused by increasing degree of polymerization; however, an increase of Al2O3 content accelerated the precipitation of dystectic MgFeAlO4, copolymerized by [AlO4]-tetrahedra and [FeO4]-tetrahedra units. It was also noted that the content of phosphorus in P-enriched phase can reach a high value as 28.71 wt pct for the slags modified by 15.17 wt pct Al2O3. The non-isothermal crystallization kinetics derived from activation energy and the structure of the slags explained by Raman spectra were further analyzed, which was well in accordance with the above analysis.

  16. Effect of P2O5 and MnO2 on crystallization of magnetic glass ceramics

    PubMed Central

    Abdel-Hameed, Salwa A.M.; Marzouk, Mohamed A.; Farag, Mohamed M.

    2013-01-01

    This work pointed out the effect of adding P2O5 and/or MnO2 on the crystallization behavior of magnetic glass ceramic in the system Fe2O3·ZnO·CaO·SiO2·B2O3. The differential thermal analysis of the quenched samples revealed decrease in the thermal effects by adding P2O5 and/or MnO2 to the base sample. The X-ray diffraction patterns show the development of nanometric magnetite crystals in a glassy matrix. Heat treatment at 800 °C for 2 h, under reducing atmosphere, caused an increase in the amount of the crystallized magnetite with the appearance of minor hematite and Ca2SiO4. The transmission electron microscope revealed a crystallite size in the range 10–30 nm. Magnetic hysteresis cycles were analyzed with a maximum applied field of 25 kOe at room temperature. The prepared magnetic glass ceramics are expected to be useful for localized treatment of cancer. PMID:25685522

  17. MAGNETIC BEHAVIOR OF IRON IONS IN THE P2O5·CaO GLASS MATRIX

    NASA Astrophysics Data System (ADS)

    ARDELEAN, I.; ANDRONACHE, C.; PǍŞCUŢǍ, P.

    The temperature dependence of the magnetic susceptibility of xFe2O3·(100-x)-[P2O5·CaO] glasses with 0P2O5·CaO glass matrix, the Fe2+ ion content is higher than that of the Fe3+ ions for glasses with x≥10 mol%. For the glasses with x>35 mol%, the evaluated values of the μeff indicate either the presence of Fe+ ions or the coordination influence on the magnetic moment of iron ions, but the presence of small quantities of the antiferromagnetic or ferrimagnetic interactions between iron ions in studied temperature range cannot be excluded. The high temperature susceptibility results indicate that the iron ions are isolated or participate in dipole-dipole interactions for glasses with x≤35 mol% and are antiferromagnetically coupled for higher contents of Fe2O3.

  18. FT-IR and thermoluminescence investigation of P2O5-BaO-K2O glass system

    NASA Astrophysics Data System (ADS)

    Ivascu, C.; Timar-Gabor, A.; Cozar, O.

    2013-11-01

    The 0.5P2O5ṡxBaOṡ(0.5-x)K2O glass system (0≤x≤0.5mol%) is investigated by FT-IR and thermoluminescence as a possible dosimetic material. FT-IR spectra show structural network modifications with the composition variations of the studied glasses. The predominant absorption bands are characterized by two broad peaks near 500 cm-1, two weak peaks around 740 cm-1 and three peaks in the 900-1270 cm-1 region. The shift in the position of the band assigned to asymmetric stretching of PO2- group, υas(PO2-) modes from ˜1100 cm-1 to 1085 cm-1 and the decrease in its relative intensity with the increasing of K2O content shows a network modifier role of this oxide.. Luminescence investigations show that by adding modifier oxides in the phosphate glass a dose dependent TL signals result upon irradiation. Thus P2O5-BaO-K2O glass system is a possible candidate material for dosimetry in the dose 0 - 50 Gy range.

  19. Zero photoelastic and water durable ZnO-SnO-P2O5-B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Saitoh, Akira; Nakata, Kohei; Tricot, Grégory; Chen, Yuanyuan; Yamamoto, Naoki; Takebe, Hiromichi

    2015-04-01

    We report properties of zero birefringent xZnO-(67-x)SnO-(33-y)P2O5-y B2O3 glasses, within 18.5 ? x ? 22 and y = 0, 3, and 10 mol. %. These compositions of boro-phosphate glasses provide both zero photoelastic constant (PEC) and improved water durability. x = 19 and y = 3 compositions show minimum PEC of -0.002 × 10-12 Pa-1, which can contribute to candidate material for fiber current sensor devise without lead. The structures of zero photoelastic glasses were investigated by Raman scattering and nuclear magnetic resonance spectroscopies. Compositions of zero PEC glasses are explained by the empirical model proposed by Zwanziger et al. [Chem. Mater. 19, 286-290 (2007)].

  20. NMR study of crystallization in MgO-CaO-SiO 2-P 2O 5 glass-ceramics

    NASA Astrophysics Data System (ADS)

    Ren, Hai-Lan; Yue, Yong; Ye, Chao-Hui; Guo, Li-Ping; Lei, Jia-Heng

    1998-08-01

    29Si and 31P magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) measurements were employed to investigate crystallization in MgO-CaO-SiO 2-P 2O 5 bioglass-ceramics. The results suggest that wollastonite (β-CaSiO 3) is separated as a new crystalline phase, corresponding to the appearance of a sharp signal in the 29Si MAS NMR spectra, while oxyapatite (Ca 10(PO 4) 6O) forms in the process of the order of the phosphorus-rich phases increasing as a whole, corresponding to the gradual narrowing of 31P MAS NMR spectra. ZnO can make the glass stable and difficult to crystallize at a low temperature, while at a high temperature, ZnO can participate in the crystallization of β-CaSiO 3 and promote it.

  1. Effects of the substitution of P2O5 by B2O3 on the structure and dielectric properties in (90-x) P2O5-xB2O3-10Fe2O3 glasses.

    PubMed

    Sdiri, N; Elhouichet, H; Dhaou, H; Mokhtar, F

    2014-01-01

    90%[xB2O3 (1-x) P2O5] 10%Fe2O3, glass systems where (x=0 mol%, 5 mol%, 10 mol%, 15 mol%, 20 mol%) was prepared via a melt quenching technique. The structure of glass is investigated at room temperature by, Raman and EPR spectroscopy. Raman studies have been performed on these glasses to examine the distribution of different borate and phosphate structural groups. We have noted an increase from 3 to 4 in the coordination number of the boron atoms from 3 to 4, i.e., the conversion of the BO3 triangular structural units into BO4 tetrahedra. The samples have been investigated by means of electron paramagnetic resonance (EPR). The results obtained from the gef=4.28 EPR line are typical of the occurrence of iron (III) occupying substitutional sites. Moreover, the dielectric sizes such as ε'(ω), ε″(ω), imaginary parts of the electrical modulus, M(*)(ω) and the loss tanδ, their variation with frequency at room temperature show a decrease in relaxation intensity with an increase in the concentration of (B2O3). On the present work, we have found a weak extinction index with our new glass. PMID:23995605

  2. Cl, P2O5, U and Br associated with mineral separates from a low and a high Ti mare basalt

    NASA Technical Reports Server (NTRS)

    Jovanovic, S.; Reed, G. W., Jr.

    1980-01-01

    Low Ti basalt 12040 and high Ti basalt 75055 have approximately the same Cl/P2O5 ratio; the Cl is that remaining after a hot water leach. Pyroxene, plagioclase and ilmenite minerals separated from the basalts also tend to have this same Cl/P2O5 ratio. This is evidence that these major minerals do not control the ratio since Cl and P would not be expected to partition to the same extent into each mineral. Olivine appears to be a special case. It is proposed that the grains measured contained inclusions with leachable and P2O5-related Cl. Dilute acid leaches of whole rock and separated minerals have the same or nearly the same Cl/P2O5 ratios as the residual samples. Apatite and whitlockite were probably the phases leached. They must be constituents of the mesostasis and are present as microminerals or coatings on major mineral grains. The acid leach results imply little or no partition of Cl and P2O5 into major minerals.

  3. Life and failure mechanism prediction of eco-friendly P2O5-SnO2-B2O3 glass frits

    NASA Astrophysics Data System (ADS)

    Choi, Hyoung-Seuk; Choi, Duck-Kyun

    2013-09-01

    Glass frits are used widely in the VFD, PDP, LCD, and OLED displays, solar cells, and automobiles. It is essential for glass frits to exhibit material properties such as low melting temperatures and coefficient of thermal expansion close to glass to prevent thermal shock and to lower the thermal stress. Glass frit containing 60%-85% of PbO lowers the melting temperature. However, PbO causes environmental pollution. In this study, we developed P2O5-SnO2-B2O3 glass frits and carried out life tests on these systems. In addition, life tests were also carried out on Pb-containing glass frits (VFD) for comparison to predict the life of the P2O5-SnO2-B2O3 systems. Subsequently, the failure mechanisms of VFD and Pb-free P2O5-SnO2-B2O3 glass frits were analyzed.

  4. Compositional effect of WO3, MoO3, and P2O5 on Raman spectroscopy of tellurite glass for broadband and high gain Raman amplifier

    NASA Astrophysics Data System (ADS)

    Yuan, J.; Yang, Q.; Chen, D. D.; Qian, Q.; Shen, S. X.; Zhang, Q. Y.; Jiang, Z. H.

    2012-05-01

    In order to obtain broadband and high Raman gain coefficient in the tellurite glass, a detailed study of the effects of WO3, MoO3, and P2O5 in TeO2-ZnO-Na2O-Nb2O5 (TZNN) glass system on the thermal stabilities and Raman spectroscopic was performed. It was found that both WO3 and MoO3 improved the glass thermal stability and enhanced the bandwidth significantly. Higher Raman gain coefficients and broader bandwidth were realized in the MoO3 modified glasses than those of WO3 added glass. The tellurite glass containing 15 mol. % MoO3 exhibits the bandwidth 1.7 times larger than the silica glass and the Raman gain coefficient is as high as 38 times that of the silica glass. Moreover, with the addition of P2O5 in TeO2-ZnO-Na2O-Nb2O5-WO3 (TZNNW) and TeO2-ZnO-Na2O-Nb2O5-MoO3 (TZNNM) glass systems, the thermal stabilities can further be improved. On the other hand, the Raman bandwidth can further be broadened, especially in the TZNNMP glass system. The tellurite glass containing 15 mol. % MoO3 and 15 mol. % P2O5 shows the bandwidth 1.9 times larger than the silica glass and maintains high Raman gain coefficient which is as high as 37 times that of the silica glass, indicating this glass is a promising candidate as new gain media for broadband Raman fiber amplifier.

  5. Long-Lasting Phosphorescent Properties of Tb3+ Doped ZnO-P2O5-SiO2 Glasses

    NASA Astrophysics Data System (ADS)

    Cao, Yuxia

    2016-03-01

    The long-lasting phosphorescent glass with the composition of ZnO-P2O5-SiO2: Tb3+ was prepared by melt-quenched method. After irradiation by 254 nm light, a visible greenish light can be observed with the naked eyes, in the dark for up to 9 h after removal of the activating light. The luminescent properties of ZnO-P2O5-SiO2: Tb3+ were studied by fluorescence spectra, afterglow spectra and thermoluminescence spectra. The results show that the luminescent properties of the glasses become better with the increase of ZnO contents. The luminescent properties of glasses increase with the increase of Tb3+ contents. When 2% of ZnO is replaced by 2% of RO (RO=CaO, SrO, BaO), the luminescent property of glasses become worse in the order of CaO, SrO, BaO. The higher the contents of RO (RO=CaO, SrO, BaO) are, the worse the luminescent properties of the glasses become.

  6. Effect of nitridation on the aqueous dissolution of Na2O-K2O-CaO-P2O5 metaphosphate glasses.

    PubMed

    Riguidel, Quentin; Muñoz, Francisco

    2011-06-01

    The use of oxynitride glasses is presented as an alternative for the preparation of bioresorbable phosphate glasses with a controlled dissolution rate. This work describes the design of oxynitride phosphate glasses within the systems of composition (50-x)Na(2)O·xCaO·50P(2)O(5) and (25-(x/2))Na(2)O·(25-(x/2))K(2)O·xCaO·50P(2)O(5) (x=5, 10, 15, 20 mol.%) throughout the processing parameters of the ammonolysis reaction and the glass composition. Mixed-alkali sodium-potassium phosphate glasses with low CaO contents present the best characteristics for nitridation. The dissolution rate has been determined by immersion of glass samples in water, at constant temperature of 37 °C, and has been discussed as a function of both modifiers composition and nitrogen content incorporated in the glasses through ammonolysis. All oxynitride glass compositions dissolve congruently and their dissolution rate decreases by more than three orders of magnitude for the highest nitrogen contents. However, it has been demonstrated that nitrogen contents as low as 2-3 wt.% (i.e. a 0.2N/P ratio) are sufficient to decrease the dissolution rate by one order of magnitude with respect to the pure oxide glasses. Novel oxynitride phosphate glasses with a controlled and congruent dissolution are proposed for future applications in biodegradable composite materials, tissue engineering or host matrices for the controlled release of drugs. PMID:21440095

  7. Crystallization Behavior and Microstructure of Silica-Free 5K2O-45CaO-50P2O5 Bioglass

    NASA Astrophysics Data System (ADS)

    Wang, Moo-Chin; Lai, You-Cheng; Shih, Wei-Jen; Shih, Ping-Yu; Chen, Guo-Ju; Li, Wang-Long

    2010-02-01

    The crystallization behavior and microstructure of silica-free 5K2O-45CaO-50P2O5 (KCP) bioglass have been studied using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning election microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). The activation energy for the KCP bioglass crystallization is found to be 337.4 kJ/mol using a nonisothermal method. The crystalline phases of the glass surface determined by XRD are KCa(PO3)3, 4CaO·3P2O5, and β-Ca(PO3)2 when the KCP bioglass is crystallized at 903 K for 4 hours. The crystalline phase of the powder samples determined by XRD is β-Ca(PO3)2 when silica-free KCP glasses crystallized at 873 to 1073 K for 8 hours. Crystallization starts at the surface of the KCP bioglass and then proceeds toward the interior of the glass matrix. The morphology of β-Ca(PO3)2 is a fibrillar shape 20 to 180 nm in length and 17 to 20 nm in diameter, with an aspect ratio ranging from 1.0 to 10.6.

  8. In-vitro study of copper doped SiO2-CaO-P2O5 system for bioactivity and antimicrobial properties

    NASA Astrophysics Data System (ADS)

    Kaur, Kulwinder; Singh, K. J.; Anand, Vikas; Kaur, Harpreet; Arora, Daljit Singh

    2015-08-01

    Samples of the xCuO-(45-x)CaO-10P2O5-45SiO2 system (x varies from 0 to 4 mole%) have been synthesized for application as biomaterials to slow or inhibit the growth of living organisms (fungi and other pathogenic microorganisms) by the combination of sol-gel and co-precipitation processes. Prepared samples have been characterized by X-Ray Diffraction, Fourier Transform Infra-Red and Field Emission Scanning Electron Microscopy techniques before and after immersion in simulated body fluid. Antimicrobial activity of samples has been investigated against Staphylococcus aureus. Releasing of Cu2+and other ions in the simulated body fluid has been determined by Atomic Absorption Spectroscopy to ensure the use of prepared material as biomaterial with good antibacterial properties.

  9. Strong white light in P2O5-Li2O-Yb2O3-Sb2O3 glass doped with Pr3+ion

    NASA Astrophysics Data System (ADS)

    Ming, Chengguo; Han, Yingdong; Song, Feng; Ren, Xiaobin; An, Liqun

    2013-01-01

    P2O5-Li2O-Yb2O3-Sb2O3 glasses doped with Pr3+ ion had been prepared to explore white-light-emitting materials. The photoluminescence spectra of the glasses were measured under 270 nm excitation. The emission color of the glass doped with 2 mol% Pr3+ ion was white to the naked eye, and the CIE coordinates (0.336, 0.319) of the sample were close to the standard equal energy white-light illumination (x=0.333, y=0.333). The present working mechanism of the commercial white-LEDs is that a yellow phosphor is excited by a blue LED chip. The emission characters are restricted by the intensity of the blue light and the thickness of the phosphor. However, the luminescent characters of our materials are not effected by the pumping light. Thus, our materials will be helpful in developing white-light-emitting materials.

  10. In vitro bioactivity evaluation, mechanical properties and microstructural characterization of Na2O-CaO-B2O3-P2O5 glasses

    NASA Astrophysics Data System (ADS)

    Abo-Naf, Sherief M.; Khalil, El-Sayed M.; El-Sayed, El-Sayed M.; Zayed, Hamdia A.; Youness, Rasha A.

    2015-06-01

    Na2O-CaO-B2O3-P2O5 glasses have been prepared by the melt-quenching method. B2O3 content was systematically increased from 5 to 30 mol%, at the expense of P2O5, in the chemical composition of these glasses. Density, Vickers microhardness and fracture toughness of the prepared glasses were measured. In vitro bioactivity of the glasses was assessed by soaking in the simulated body fluid (SBF) at 37 ± 0.5 °C for 3, 7, 14 and 30 days. The glasses were tested in the form of glass grains as well as bulk slabs. The structure and composition of the solid reaction products were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The kinetics of degradation of the glass particles were monitored by measuring the weight loss of the particles and the ionic concentration of Ca, P and B in the SBF solution using inductive coupled plasma-atomic emission spectroscopy (ICP-AES). The obtained results revealed the formation of a bioactive hydroxyapatite (HA) layer, composed of nano-crystallites, on the surface of glass grains after the in vitro assays. The results have been used to understand the formation of HA as a function of glass composition and soaking time in the SBF. It can be pointed out that increasing B2O3 content in glass composition enhances the bioactivity of glasses. The nanometric particle size of the formed HA and in vitro bioactivity of the studied glasses make them possible candidates for tissue engineering application.

  11. Energy transfer and optical gain properties of P2O5-ZnO-LiF: (Yb3+, Er3+) glasses

    NASA Astrophysics Data System (ADS)

    Reddy, C. Parthasaradhi; Naresh, V.; Reddy, K. T. Ramakrishna; Buddhudu, S.

    2015-06-01

    The present paper reports on the results pertaining to the emission properties of 0.5 mol% Er3+ and together (0.5 Yb3+ /0.5 Er3+) doped PZL (P2O5-ZnO-LiF) glasses prepared by a melt quenching method. From the optical absorption data, absorption and stimulated emission cross-sections have been evaluated using McCumber's theory and further cross-sectional gain has also been computed for Yb3+/Er3+ doped glass. On exciting the single (Er3+) and dual rare earth ions (Yb3+/Er3+) doped glass sample at ?exci = 379 nm, three emission bands in the visible region 2H11/2?4I15/2 (526 nm), 4S3/2?4I15/2 (549 nm) and 4F9/2?4I15/2 (664 nm) are observed and while at ?exci = 980 nm (Laser Diode) excitation a broad emission at 1530 nm attributed to 4H13/2?4I15/2 is observed in the NIR region. The enhancement in visible and NIR emission intensities with the addition of Yb3+ to Er3+ due to an energy transfer process from Yb3+ to Er3+ has been explained in terms of an energy level diagram.

  12. Neutron scattering study on cathode LiMn2O4 and solid electrolyte 5(Li2O)(P2O5)

    NASA Astrophysics Data System (ADS)

    Kartini, E.; Putra, Teguh P.; Jahya, A. K.; Insani, A.; Adams, S.

    2014-09-01

    Neutron scattering is very important technique in order to investigate the energy storage materials such as lithium-ion battery. The unique advantages, neutron can see the light atoms such as Hydrogen, Lithium, and Oxygen, where those elements are negligible by other corresponding X-ray method. On the other hand, the energy storage materials, such as lithium ion battery is very important for the application in the electric vehicles, electronic devices or home appliances. The battery contains electrodes (anode and cathode), and the electrolyte materials. There are many challenging to improve the existing lithium ion battery materials, in order to increase their life time, cyclic ability and also its stability. One of the most scientific challenging is to investigate the crystal structure of both electrode and electrolyte, such as cathodes LiCoO2, LiMn2O4 and LiFePO4, and solid electrolyte Li3PO4. Since all those battery materials contain Lithium ions and Oxygen, the used of neutron scattering techniques to study their structure and related properties are very important and indispensable. This article will review some works of investigating electrodes and electrolytes, LiMn2O4 and 5(Li2O)(P2O5), by using a high resolution powder diffraction (HRPD) at the multipurpose research reactor, RSG-Sywabessy of the National Nuclear Energy Agency (BATAN), Indonesia.

  13. Gel-derived materials of a CaO-P(2)O(5)-SiO(2) system modified by boron, sodium, magnesium, aluminum, and fluorine compounds.

    PubMed

    Laczka, M; Cholewa-Kowalska, K; Laczka-Osyczka, A; Tworzydlo, M; Turyna, B

    2000-12-15

    Bioactive glass-ceramic materials of the CaO-P(2)O(5)-SiO(2) system modified by adding boron, magnesium, sodium, fluorine, and aluminum were obtained using the sol-gel method. Gel-derived materials were produced in the pellet form obtained by compression of powders as well as in coatings on glass slides. The materials obtained were examined in vitro with regard to the ability of calcium phosphate layer to form on the material surface as the result of contact with simulated body fluid (SBF). SBF pH changes and calcium solubility in this solution were determined and scanning electron microscopy, energy-dispersive X-ray analysis, and infrared spectroscopy studies were conducted before and after contact of the materials with SBF. The gels modified by aluminum were amorphous, whereas the sodium and fluorine additives promoted the bulk crystallization of gel-derived materials. The ability of calcium phosphates to crystallize on the surface of gel-derived materials depended only slightly on the types of additives applied, and the character of this dependence was different from that observed in melted glasses. Moreover, to estimate the biocompatibility of gel-derived coatings, we examined the proliferation, collagen synthesis, adhesion, and morphology of fibroblasts (NRK cells) cultured in the presence of gel-derived materials. The results of these experiments showed that none of the tested materials significantly reduced any cell function. PMID:11033542

  14. Preparation, structure and bioactivity of xAu 2O 3·(100 - x)[P 2O 5·CaO] glass system

    NASA Astrophysics Data System (ADS)

    Regos, Adriana N.; Ardelean, I.

    2011-12-01

    Gold doped calcium phosphate glasses were prepared by the melting method. The structure of Au 2O 3-P 2O 5-CaO glasses is investigated using X-ray diffraction, infrared absorption and Raman scattering. The depth characterization of their structures is essential for the understanding of the properties of biocompatible materials. Thermal analysis DTA and TGA were also made to study behavior under different temperature regions and to see chemical changes versus time and temperature of these glasses. Bioactivity of the glasses was investigated in vitro by examining apatite formation on the surface of glasses treated in acellular simulated body fluid (SBF) with ion concentrations nearly equal to those in human blood plasma. Formation of bioactive apatite layer on the samples treated in SBF for 28 days at 37 °C was confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effect of SBF soaking induces structural changes on the surface, reflected by the appearance of nano-crystalline particles agglomerated into micro-aggregates.

  15. Synthesis and characterization of phosphates in molten systems Cs 2O-P 2O 5-CaO- MIII2O 3 ( MIII—Al, Fe, Cr)

    NASA Astrophysics Data System (ADS)

    Zatovsky, Igor V.; Strutynska, Nataliya Yu.; Baumer, Vyacheslav N.; Slobodyanik, Nikolay S.; Ogorodnyk, Ivan V.; Shishkin, Oleg V.

    2011-03-01

    The crystallization of complex phosphates from the melts of Cs 2O-P 2O 5-CaO- MIII2O 3 ( MIII—Al, Fe, Cr) systems have been investigated at fixed value Cs/P molar ratios equal to 0.7, 1.0 and 1.3 and Са/Р=0.2 and Ca/ МIII=1. The fields of crystallization of CsCaP 3O 9, β-Ca 2P 2O 7, Cs 2CaP 2O 7, Cs 3CaFe(P 2O 7) 2, Ca 9MIII(PO 4) 7 ( MIII—Fe, Cr), Cs 0.63Ca 9.63Fe 0.37(PO 4) 7 and CsCa 10(PO 4) 7 were determined. Obtained phosphates were investigated using powder X-ray diffraction and FTIR spectroscopy. Novel whitlockite-related phases CsCa 10(PO 4) 7 and Cs 0.63Ca 9.63Fe 0.37(PO 4) 7 have been characterized by single crystal X-ray diffraction: space group R3c, a=10.5536(5) and 10.5221(4) Å, с=37.2283(19) and 37.2405(17) Å, respectively.

  16. Thermally Tunable Dual Emission of the d(8)-d(8) Dimer [Pt2(μ-P2O5(BF2)2)4](4.).

    PubMed

    Hofbeck, Thomas; Lam, Yan Choi; Kalbáč, Martin; Záliš, Stanislav; Vlček, Antonín; Yersin, Hartmut

    2016-03-01

    High-resolution fluorescence, phosphorescence, as well as related excitation spectra, and, in particular, the emission decay behavior of solid [Bu4N]4[Pt2(μ-P2O5(BF2)2)4], abbreviated Pt(pop-BF2), have been investigated over a wide temperature range, 1.3-310 K. We focus on the lowest excited states that result from dσ*pσ (5dz(2)-6pz) excitations, i.e., the singlet state S1 (of (1)A2u symmetry in D4h) and the lowest triplet T1, which splits into spin-orbit substates A1u((3)A2u) and Eu((3)A2u). After optical excitation, an unusually slow intersystem crossing (ISC) is observed. As a consequence, the compound shows efficient dual emission, consisting of blue fluorescence and green phosphorescence with an overall emission quantum yield of ∼100% over the investigated temperature range. Our investigation sheds light on this extraordinary dual emission behavior, which is unique for a heavy-atom transition metal compound. Direct ISC processes in Pt(pop-BF2) are largely forbidden due to spin-, symmetry-, and Franck-Condon overlap-restrictions and, therefore, the ISC time is as long as 29 ns for T < 100 K. With temperature increase, two different thermally activated pathways, albeit still relatively slow, are promoted by spin-vibronic and vibronic mechanisms, respectively. Thus, distinct temperature dependence of the ISC processes results and, as a consequence, also of the fluorescence/phosphorescence intensity ratio. The phosphorescence lifetime also is temperature-dependent, reflecting the relative population of the triplet T1 substates Eu and A1u. The highly resolved phosphorescence shows a ∼220 cm(-1) red shift below 10 K, attributable to zero-field splitting of 40 cm(-1) plus a promoting vibration of 180 cm(-1). PMID:26909653

  17. MAS-NMR investigations of the crystallization behaviour of lithium aluminum silicate (LAS) glasses containing P 2O 5 and TiO 2 nucleants

    NASA Astrophysics Data System (ADS)

    Ananthanarayanan, A.; Kothiyal, G. P.; Montagne, L.; Revel, B.

    2010-06-01

    Lithium aluminum silicate (LAS) glass of composition (mol%) 20.4Li 2O-4.0Al 2O 3-68.6SiO 2-3.0K 2O-2.6B 2O 3-0.5P 2O 5-0.9TiO 2 was prepared by melt quenching. The glass was then nucleated and crystallized based on differential thermal analysis (DTA) data and was characterized by 29Si, 31P, 11B and 27Al MAS-NMR. XRD and 29Si NMR showed that lithium metasilicate (Li 2SiO 3) is the first phase to c form followed by cristobalite (SiO 2) and lithium disilicate (Li 2Si 2O 5). 29Si MAS-NMR revealed a change in the network structure already for the glasses nucleated at 550 °C. Since crystalline Li 3PO 4, as observed by 31P MAS-NMR, forms concurrently with the silicate phases, we conclude that crystalline Li 3PO 4 does not act as a nucleating agent for lithium silicate phases. Moreover, 31P NMR indicates the formation of M-PO 4 ( M=B, Al or Ti) complexes. The presence of BO 3 and BO 4 structural units in all the glass/glass-ceramic samples is revealed through 11B MAS-NMR. B remains in the residual glass and the crystallization of silicate phases causes a reduction in the number of alkali ions available for charge compensation. As a result, the number of trigonally coordinated B (BO 3) increases at the expense of tetrahedrally coordinated B (BO 4). The 27Al MAS-NMR spectra indicate the presence of tetrahedrally coordinated Al species, which are only slightly perturbed by the crystallization.

  18. Electrical mobility of silver ion in Ag2O-B2O3-P2O5-TeO2 glasses.

    PubMed

    Sklepi?, Kristina; Vorokhta, Maryna; Mošner, Petr; Koudelka, Ladislav; Moguš-Milankovi?, Andrea

    2014-10-16

    The effect of adding TeO(2) into (100 - x)[0.5Ag(2)O - 0.1B(2)O(3) - 0.4P(2)O(5)] - xTeO(2), with 0-80 mol % TeO(2) glass, on the structural changes and electrical properties has been investigated. DSC and thermodilatomery were used to study their thermal behavior, structure was studied by Raman spectroscopy, and electrical properties have been studied by impedance spectroscopy over a wide temperature and frequency range. The introduction of TeO(2) as a third glass former to the glass network causes the structural transformation from TeO(3) (tp) to TeO(4) (tbp) which contributes to the changes in conductivity. The glasses with low TeO(2) content show only a slow decrease in dc conductivity with addition of TeO(2) due to the increase of the number of nonbridging oxygens, which increases the mobility of Ag(+) ions. The steep decrease in conductivity for glasses containing more than 40 mol % TeO(2) is a result of decrease of the Ag(2)O content and stronger cross-linkage in glass network through the formation of more Te-(eq)O(ax)-Te bonds in TeO(4) tbp units. The glasses obey ac conductivity scaling with respect to temperature, implying that the dynamic process is not temperature dependent. On the other hand, the scaling of the spectra for different glass compositions showed the deviations from the Summerfield scaling because of the local structural disorder which occurs as a result of the structural modifications in the tellurite glass network. PMID:25242657

  19. Influence of fluoride additions on biological and mechanical properties of Na2O-CaO-SiO2-P2O5 glass-ceramics.

    PubMed

    Li, H C; Wang, D G; Hu, J H; Chen, C Z

    2014-02-01

    Two series of Na2O-CaO-SiO2-P2O5 glass-ceramics doped with NH4HF2 (G-NH4HF2) or CaF2 (G-CaF2) have been prepared by sol-gel method. The glass-ceramic phase composition and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The mechanical properties and thermal expansion coefficient were measured by a microhardness tester, an electronic tensile machine and a thermal expansion coefficient tester. The structure difference between these two glass-ceramics was investigated by Fourier transform infrared spectroscopy (FTIR), and the in vitro bioactivity of the glass-ceramics was determined by in vitro simulated body fluid (SBF) immersion test. The hemolysis test, in vitro cytotoxicity test, systemic toxicity test and the implanted experiment in animals were used to evaluate the biocompatibility of the glass-ceramics. The mechanical properties of sample G-NH4HF2 are lower than that of sample G-CaF2, and the bioactivity of sample G-NH4HF2 is better than that of sample G-CaF2. The thermal expansion coefficients of these two glass-ceramics are all closer to that of Ti6Al4V. After 7 days of SBF immersion, apatites were induced on glass-ceramic surface, indicating that the glass-ceramics have bioactivity. The hemolysis test, in vitro cytotoxicity test and systemic toxicity test demonstrate that the glass-ceramics do not cause hemolysis reaction, and have no toxicity to cell and living animal. The implanted experiment in animals shows that bone tissue can form a good osseointegration with the implant after implantation for two months, indicating that the glass-ceramics are safe to serve as implants. PMID:24411365

  20. Thermal and structural characterization of erbium-doped borosilicate fibers with low silica content containing various amounts of P2O5 and Al2O3

    NASA Astrophysics Data System (ADS)

    Bourhis, Kevin; Shpotyuk, Yaroslav; Massera, Jonathan; Aallos, Ville; Jouan, Thierry; Boussard-Plédel, Catherine; Bureau, Bruno; Petit, Laeticia; Koponen, Joona; Hupa, Leena; Hupa, Mikko; Ferraris, Monica

    2014-11-01

    We report results on the processing and characterization of different glass preforms and single core fibers within the SiO2-Na2O-B2O3-Er2O3-P2O5-Al2O3 system. Micro-Raman spectroscopy was used to identify post-draw structural modification. The differences in the micro-Raman spectra recorded on the preform and on the fiber glass were attributed to a change in the structure induced by the drawing process. Changes in the silicate network organization and small scale molecular orientation within the glass matrix are suspected to occur during the fiber drawing process. We found that the extent in the changes between the preform and fiber properties depend on the glass composition. The glass network of the Al-containing fiber is expected to be less sensitive to the drawing process than that of the fiber matrix as the network of this Al-containing fiber is formed by a larger number of Si-BO units in the network and neutral three-coordinated boron compared to the network of the fiber matrix. From the micro-Raman spectra, formation of small crystals is suspected to occur in the P-containing glasses during the fiber drawing process. The resulting fibers were found to have propagation losses at 1330 nm and Er3+ absorption between (7 ± 1) and (25 ± 1) dB/m and (36 ± 1) and (47 ± 1) dB/m, respectively, depending on the glass composition.

  1. A new and economic approach to synthesize and fabricate bioactive diopside ceramics using a modified domestic microwave oven. Part 2: effect of P2O5 additions on diopside bioactivity and mechanical properties.

    PubMed

    Zouai, Souheila; Harabi, Abdelhamid; Karboua, Noureddine; Harabi, Esma; Chehlatt, Sihem; Barama, Salah-Edine; Zaiou, Soumia; Bouzerara, Ferhat; Guerfa, Fatiha

    2016-04-01

    In this work, diopside based ceramics was obtained by solid state reaction using conventional sintering (CS) and microwave sintering (MS). Moreover, different amounts of P2O5 (0.5-5.0wt.%) have been added. It has been found that a relative density up to 95% theoretical was obtained for diopside containing 2.0 and 5.0wt.% P2O5, sintered at 1250°C for 2h and at 1075°C only for 15min using CS and MS. Excellent values of micro hardness (7.4±0.1GPa) and 3 point flexural strength (about 270MPa) for samples containing 5wt.% P2O5, sintered at 1075°C for 15min using MS were measured. Besides this, a relatively low weight loss ratio has been measured (0.01%) for diopside samples containing 5wt.% P2O5, sintered under the same conditions, after soaking in physiological salt solution for 2days. Additionally, the bioactivity of diopside by the possibility of formation of apatite on the surface of pure diopside and diopside containing 2wt.% of P2O5 immersed in simulated body fluid (SBF) was also confirmed. Finally, particular nano-sized of Carbonated hydroxyapatite (CHA) crystals (rice shaped) were formed and covered the surface of these samples, soaked in SBF solution for 14days. PMID:26838883

  2. Luminescence properties of Sm(3+)-doped P(2)O(5)-PbO-Nb(2)O(5) glass under high pressure.

    PubMed

    Praveena, R; Venkatramu, V; Babu, P; Jayasankar, C K; Tröster, Th; Sievers, W; Wortmann, G

    2009-01-21

    Samarium doped lead phosphate glass modified with niobium having a composition (in mol%) of 55P(2)O(5)+39.5PbO+5Nb(2)O(5)+0.5Sm(2)O(3) has been prepared by the conventional melt quenching technique. The emission spectra and the decay curves for the (4)G(5/2) level of Sm(3+) ions have been measured as a function of pressure up to 23.6 GPa at room temperature. A discontinuity in the observed shifts and crystal-field splittings as a function of pressure around 9-10 GPa suggests that a phase transition is taking place in the glass matrix. The [Formula: see text], (6)H(7/2) and (6)H(9/2) transitions are shifted towards the lower energy side with magnitudes of -7.1, -7.6 and -5.5 cm(-1) GPa(-1) up to 8.9 GPa (phase 1) and -5.6, -4.9 and -4.4 cm(-1) GPa(-1) beyond 10.3 GPa (phase 2), respectively. A much stronger increase in the splitting of the [Formula: see text] and [Formula: see text] Stark levels with pressure is observed in phase 1 than in phase 2. The lifetime of the (4)G(5/2) level decreases from 2.29 ms (0 GPa) to 0.64 ms (23.6 GPa) with pressure. The decay curves of the (4)G(5/2) level exhibit non-exponential behavior for all the pressures and were fitted by the generalized Yokota-Tanimoto model to probe the nature of the energy transfer process. The best fits with S = 6 indicate that the energy transfer between donor and acceptor is of dipole-dipole type. The crystal-field splitting experienced by the Sm(3+) ions in the title glass are found to be larger than those found in borate, K-Ba-Al phosphate and tellurite glasses. PMID:21817267

  3. Effect of boron oxide addition on fibre drawing, mechanical properties and dissolution behaviour of phosphate-based glass fibres with fixed 40, 45 and 50?mol% P2O5

    PubMed Central

    Sharmin, Nusrat; Parsons, Andrew J; Rudd, Chris D

    2014-01-01

    Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed with P2O5 content less than 50?mol% showed that continuous manufacture without breakage was very difficult. In this study, nine phosphate-based glass formulations from the system P2O5-CaO-Na2O-MgO-B2O3 were prepared with P2O5 contents fixed at 40, 45 and 50?mol%, where Na2O was replaced by 5 and 10?mol% B2O3 and MgO and CaO were fixed to 24 and 16?mol%, respectively. The effect of B2O3 addition on the fibre drawing, fibre mechanical properties and dissolution behaviour was investigated. It was found that addition of 5 and 10?mol% B2O3 enabled successful drawing of continuous fibres from glasses with phosphate (P2O5) contents fixed at 40, 45 and 50?mol%. The mechanical properties of the fibres were found to significantly increase with increasing B2O3 content. The highest tensile strength (1200?±?130?MPa) was recorded for 45P2O5-16CaO-5Na2O-24MgO-10B2O3 glass fibres. The fibres were annealed, and a comparison of the mechanical properties and mode of degradation of annealed and non-annealed fibres were investigated. A decrease in tensile strength and an increase in tensile modulus were observed for the annealed fibres. An assessment of the change in mechanical properties of both the annealed and non-annealed fibres was performed in phosphate-buffered saline (PBS) at 37? for 28 and 60 days, respectively. Initial loss of mechanical properties due to annealing was found to be recovered with degradation. The B2O3-containing glass fibres were found to degrade at a much slower rate as compared to the non-B2O3-containing fibres. Both annealed and non-annealed fibres exhibited a peeling effect of the fibre's outer layer during degradation. PMID:24939962

  4. Structure, glass transition temperature and spectroscopic properties of 10Li2O-xP2O5-(89-x)TeO2-1CuO (5?x?25 mol%) glass system.

    PubMed

    Upender, G; Babu, J Chinna; Mouli, V Chandra

    2012-04-01

    X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), infrared (IR), Raman, electron paramagnetic resonance (EPR) and optical absorption studies on 10Li2O-xP2O5-(89-x)TeO2-1CuO glasses (where x=5, 10, 15, 20 and 25 mol%) have been carried out. The amorphous nature of the glasses was confirmed using XRD and FESEM measurements. The glass transition temperature (Tg) of glass samples have been estimated from DSC traces and found that the Tg increases with increasing P2O5 content. Both the IR and Raman studies have been showed that the present glass system consists of [TeO3], [TeO4], [PO3] and [PO4] units. The spin-Hamiltonian parameters such as g?, g?, and A? have been determined from EPR spectra and it was found that the Cu2+ ion is present in tetragonal distorted octahedral site with [Formula: see text] as the ground state. Bonding parameters and bonding symmetry of Cu2+ ions have been calculated by correlating EPR and optical data and were found to be composition dependent. PMID:22248455

  5. The influence of phosphorus precursors on the synthesis and bioactivity of SiO2-CaO-P 2O 5 sol-gel glasses and glass-ceramics.

    PubMed

    Siqueira, Renato Luiz; Zanotto, Edgar Dutra

    2013-02-01

    Bioactive glasses and glass-ceramics of the SiO(2)-CaO-P(2)O(5) system were synthesised by means of a sol-gel method using different phosphorus precursors according to their respective rates of hydrolysis-triethylphosphate (OP(OC(2)H(5))(3)), phosphoric acid (H(3)PO(4)) and a solution prepared by dissolving phosphorus oxide (P(2)O(5)) in ethanol. The resulting materials were characterised by differential scanning calorimetry and thermogravimetry, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and by in vitro bioactivity tests in acellular simulated body fluid. The different precursors significantly affected the main steps of the synthesis, beginning with the time required for gel formation. The most striking influence of these precursors was observed during the thermal treatments at 700-1,200 °C that were used to convert the gels into glasses and glass-ceramics. The samples exhibited very different mineralisation behaviours; especially those prepared using the phosphoric acid, which had a reduced onset temperature of crystallisation and an increased resistance to devitrification. However, all resulting materials were bioactive. The in vitro bioactivity of these materials was strongly affected by the heat treatment temperature. In general, their bioactivity decreased with increasing treatment temperature. For crystallised samples obtained above 900 °C, the bioactivity was favoured by the presence of two crystalline phases: wollastonite (CaSiO(3)) and tricalcium phosphate (?-Ca(3)(PO(4))(2)). PMID:23114636

  6. Effects of Substitution of K2O for Na2O on the Bioactivity of CaO-Na2O-SiO2-P2O5 glasses

    NASA Astrophysics Data System (ADS)

    Kim, Taehee; Hwang, Chawon; Gwoo, Donggun; Park, Hoyyul; Ryu, Bong-Ki

    2012-10-01

    The compositional dependences of bioactivity, thermal properties, atomic structure, and surface morphology have been investigated in the CaO-Na2O-SiO2-P2O5 system; this system is known as a bioglass. 45S5 Bioglass® is known to be a general and highly bioactive material. However, the bioactivity of this glassy material is expected to be improved by modifying the alkali-metal composition. Thermal properties, density, and molar volume were measured to investigate the structural packing. FT-IR spectra and X-ray diffraction were used to confirm the structures of these glasses. The morphology was examined using field emission electron microscopy, and the formation of a Ca-P layer was studied using an energy-dispersive system. This study shows that the tendency to form a calcium phosphate layer is increased with the substitution of K2O for Na2O.

  7. Li2Osbnd LiFsbnd ZnF2sbnd B2O3sbnd P2O5: MnO glasses - Thermal, structural, optical and luminescence characteristics

    NASA Astrophysics Data System (ADS)

    Parthasaradhi Reddy, C.; Naresh, V.; Ramakrishna Reddy, K. T.

    2016-01-01

    Here, we present results pertaining to thermal, structural, optical and photoluminescence properties of Li2Osbnd LiFsbnd ZnF2sbnd B2O3sbnd P2O5: (0.1-1.5 mol.%) MnO glasses. DTA profiles revealed a change in glass transition temperature with the addition of MnO suggesting an increase in glass stability. The modifications in structural units are interpreted from FTIR and Raman spectral profiles, which confirm the formation of stable Psbnd Osbnd B bonds. The host Li2Osbnd LiFsbnd ZnF2sbnd B2O3sbnd P2O5 (labelled as LZBP) glass exhibits emission in the blue region on excitation with 361 nm. The red shift in optical absorption edge and decrease in energy of band gap as a function of MnO concentration is analysed from Tauc's plot. The nature of local symmetry around manganese ions in LZBP matrix has been understood by evaluating the crystal field strength (Dq) and Racah inter-electronic repulsion parameters (B &C) from absorption spectrum and electron-lattice interaction energy (Sħω) factor from emission spectrum. The emission spectra of (0.1-1.5 mol.%) Mn2+: LZPB glasses have shown broad band at 613 nm assigned to electronic transition 4T1g(G) → 6A1g(S) displaying orange-red emission upon excitation at 413 nm. Octahedral coordination of Mn2+ ions has been estimated from the position of emission in luminescence spectra. The effect of Mn2+ concentration on emission properties has been discussed from lifetime curves and energy level scheme.

  8. Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses

    PubMed Central

    Kaur, Gurbinder; Pickrell, G.; Kimsawatde, G.; Homa, D.; Allbee, H. A.; Sriranganathan, N.

    2014-01-01

    CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol–gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations. PMID:24637634

  9. Studies on influence of aluminium ions on the bioactivity of B2O3-SiO2-P2O5-Na2O-CaO glass system by means of spectroscopic studies

    NASA Astrophysics Data System (ADS)

    Mohini, G. Jagan; Krishnamacharyulu, N.; Sahaya Baskaran, G.; Rao, P. Venkateswara; Veeraiah, N.

    2013-12-01

    Bioactive multi component glasses of the composition of 27.4 B2O3-6.4 SiO2-2.5 P2O5-25.5 Na2O-(38.2 - x) CaO: x Al2O3 (x between 0 and 3.2) were synthesized, by melt quenching technique and their bioactivity was investigated as a function of Al2O3 concentration. Initially, optical absorption and infrared spectra were recorded and analyzed in order to have some pre-understanding over structural aspects of the glasses. For understanding the bioactivity, the samples were immersed in simulated body fluid (SBF) solution for prolonged times (∼30 days) and the weight loss measurements were carried out. The spectroscopic studies were repeated on the post immersed samples. From the comparison of the analysis of the spectroscopic data of both pre-immersed and post-immersed samples together with the information on variation of pH value of residual solution as a function of immersion time, it is concluded that the participation of aluminium ions in tetrahedral positions is hindrance for the formation of HA layer and for the bioactivity of the samples.

  10. Understanding the magnetic behavior of heat treated CaO-P2O5-Na2O-Fe2O3-SiO2 bioactive glass using electron paramagnetic resonance studies

    NASA Astrophysics Data System (ADS)

    Shankhwar, Nisha; Kothiyal, G. P.; Srinivasan, A.

    2014-09-01

    Bioactive glass of composition 41CaO-44SiO2-4P2O5-8Fe2O3-3Na2O has been heat treated in the temperature (TA) range of 750-1150 °C for time periods (tA) ranging from 1 h to 3 h to yield magnetic bioactive glass ceramics (MBCs). X-ray diffraction studies indicate the presence of bone mineral (hydroxyapatite and wollastonite) and magnetic (magnetite and α-hematite) phases in nanocrystalline form in the MBCs. Electron paramagnetic resonance (EPR) study was carried out to understand the variation in saturation magnetization and coercivity of the MBCs with TA and tA. These studies reveal the nature and amount of iron ions present in the MBCs and their interaction in the glassy oxide matrix as a function of annealing parameters. The deterioration in the magnetic properties of the glass heat treated above 1050 °C is attributed to the crystallization of the non-magnetic α-hematite phase. These results are expected to be useful in the application of these MBCs as thermoseeds in hyperthermia treatment of cancer.

  11. Influence of heat treatments upon the mechanical properties and in vitro bioactivity of ZrO2-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics.

    PubMed

    Li, Huan-Cai; Wang, Dian-Gang; Meng, Xiang-Guo; Chen, Chuan-Zhong

    2014-09-01

    Zirconia-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics are prepared using sintering techniques, and a series of heat treatment procedures are designed to obtain a glass-ceramic with improved properties. The crystallization behavior, phase composition, and morphology of the glass-ceramics are characterized. The bending strength, elastic modulus, fracture toughness, and microhardness of the glass-ceramics are investigated, and the effect mechanism of heat treatments upon the mechanical properties is discussed. The bioactivity of glass-ceramics is then evaluated using the in vitro simulated body fluid (SBF) soaking test, and the mechanism whereby apatite forms on the glass-ceramic surfaces in the SBF solution is discussed. The results indicate that the main crystal phase of the G-24 sample undergoing two heat treatment procedures is Ca5(PO4)3F (fluorapatite), and those of the G-2444 sample undergoing four heat treatment procedures are Ca5(PO4)3F and β-CaSiO3 (β-wollastonite). The heat treatment procedures are found to greatly influence the mechanical properties of the glass-ceramic, and an apatite layer is induced on the glass-ceramic surface after soaking in the SBF solution. PMID:25280855

  12. Compositional dependence of bioactivity of glasses in the system Na2O-K2O-MgO-CaO-B2O3-P2O5-SiO2.

    PubMed

    Brink, M; Turunen, T; Happonen, R P; Yli-Urpo, A

    1997-10-01

    The bioactivity, i.e., bone-bonding ability, of 26 glasses in the system Na2O-K2O-MgO-CaO-B2O3-P2O5-SiO2 was studied in vivo. This investigation of bioactivity was performed to establish the compositional dependence of bioactivity, and enabled a model to be developed that describes the relation between reactions in vivo and glass composition. Reactions in vivo were investigated by inserting glass implants into rabbit tibia for 8 weeks. The glasses and the surrounding tissue were examined using scanning electron microscopy (SEM), light microscopy, and energy-dispersive X-ray analysis (EDXA). For most of the glasses containing < 59 mol % SiO2, SEM and EDXA showed two distinct layers at the glass surface after implantation, one silica-rich and another containing calcium phosphate. The build-up of these layers in vivo was taken as a sign of bioactivity. The in vivo experiments showed that glasses in the investigated system are bioactive when they contain 14-30 mol % alkali oxides, 14-30 mol % alkaline earth oxides, and < 59 mol % SiO2. Glasses containing potassium and magnesium bonded to bone in a similar way as bioactive glasses developed so far. PMID:9335356

  13. Sol-gel synthesis of quaternary (P2O5)55-(CaO)25-(Na2O)(20-x)-(TiO2) x bioresorbable glasses for bone tissue engineering applications (x = 0, 5, 10, or 15).

    PubMed

    Foroutan, Farzad; Walters, Nick J; Owens, Gareth J; Mordan, Nicola J; Kim, Hae-Won; de Leeuw, Nora H; Knowles, Jonathan C

    2015-08-01

    In the present study, we report a new and facile sol-gel synthesis of phosphate-based glasses with the general formula of (P2O5)55-(CaO)25-(Na2O)(20-x)-(TiO2) x , where x = 0, 5, 10 or 15, for bone tissue engineering applications. The sol-gel synthesis method allows greater control over glass morphology at relatively low processing temperature (200 °C) in comparison with phosphate-based melt-derived glasses (~1000 °C). The glasses were analyzed using several characterization techniques, including x-ray diffraction (XRD), (31)P magic angle spinning nuclear magnetic resonance ((31)P MAS-NMR), Fourier transform infrared (FTIR) spectroscopy and energy-dispersive x-ray (EDX) spectroscopy, which confirmed the amorphous and glassy nature of the prepared samples. Degradation was assessed by measuring the ion release and pH change of the storage medium. Cytocompatibility was also confirmed by culturing osteoblast-like osteosarcoma cell line MG-63 on the glass microparticles over a seven-day period. Cell attachment to the particles was imaged using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results revealed the potential of phosphate-based sol-gel derived glasses containing 5 or 10 mol% TiO2, with high surface area, ideal dissolution rate for cell attachment and easily metabolized dissolution products, for bone tissue engineering applications. PMID:26306553

  14. Influences of TiO2 Addition on the Crystallization Behavior, Microstructure, and Magnetic Properties of Li2O-MnO2-Fe2O3-CaO-P2O5-SiO2 Glasses

    NASA Astrophysics Data System (ADS)

    Cheng, Huy-Zu; Lin, Huey-Jiuan; Wang, Moo-Chin; Wang, Chien-Fa; Hsi, Chi-Shiung; Zhao, XiuJian; Jiang, Hong; Li, Chang-Jiu; Lu, Peng

    2015-05-01

    Influences of TiO2 addition on the phase transformation, microstructure, and magnetic properties of Li2O-MnO2-Fe2O3-CaO-P2O5-SiO2 (LMFCPS) glass have been studied using DTA, XRD, SEM, EDS, TEM, SAED, and SQUID. When LMFCPS glass, with and without TiO2 content, is crystallized at 1123 K (850 °C) for 2 hours, the magnetite (FeFe2O4), β-wollastonite (β-CaSiO3), lithium orthophosphate (Li3PO4), and triphylite (Li(Mn0.5Fe0.5)PO4) phases are formed. The β-wollastonite and lithium silicate formed with evident directionality were observed in the LMFCPS glass-ceramics without adding TiO2. However, when the LMFCPS glass with various TiO2 content is crystallized at 1123 K (850 °C) for 16 hours, very small remnant magnetic induction and coercive field hysteresis loops were found showing the ferromagnetic property in a magnetic field smaller than 2000 Oe. Additionally, when LMFCPS glass with various TiO2 contents is crystallized at 1123 K (850 °C) for 16 hours, the glass-ceramics showed super-paramagnetic property in a magnetic field of 60 kOe due to the small grains of the iron-rich phases.

  15. Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses.

    PubMed

    Kaur, Gurbinder; Pickrell, G; Kimsawatde, G; Homa, D; Allbee, H A; Sriranganathan, N

    2014-01-01

    CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol-gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations. PMID:24637634

  16. Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses

    NASA Astrophysics Data System (ADS)

    Kaur, Gurbinder; Pickrell, G.; Kimsawatde, G.; Homa, D.; Allbee, H. A.; Sriranganathan, N.

    2014-03-01

    CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol-gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations.

  17. Effect of pH values on surface modification and solubility of phosphate bioglass-ceramics in the CaO-P 2O 5-Na 2O-SrO-ZnO system

    NASA Astrophysics Data System (ADS)

    Li, Xudong; Cai, Shu; Zhang, Wenjuang; Xu, Guohua; Zhou, Wei

    2009-08-01

    The bioactive glass-ceramics in the CaO-P 2O 5-Na 2O-SrO-ZnO system were synthesized by the sol-gel technique, and then chemically treated at different pH values to study the solubility and surface modification. Samples sintered at 650 °C for 4 h consisted of the crystalline phase β-Ca 2P 2O 7 and the glass matrix. After soaking in the solution at pH 1.0, the residual glass matrix on the surface appeared entirely dissolved and no new phase could be detected. Whereas at pH 3.0, web-like layer exhibiting peaks corresponding to CaP 2O 6 was formed and covered the entire surface of the sample. When conducted at pH 10.0, only part of the glass matrix was dissolved and a new phase Ca 4P 6O 19 was precipitated, forming the petaline layer. The chemical treatment can easily change the surface morphologies and phase composition of this bioactive glass-ceramics. The higher level of surface roughness resulting from the new-formed layer would improve the interface bonding and benefit for cell adhesion.

  18. Structural and magnetic properties of SiO2-CaO-Na2O-P2O5 containing BaO-Fe2O3 glass-ceramics

    NASA Astrophysics Data System (ADS)

    Leenakul, W.; Kantha, P.; Pisitpipathsin, N.; Rujijanagul, G.; Eitssayeam, S.; Pengpat, K.

    2013-01-01

    The incorporation method was employed to produce bioactive glass-ceramics from the BaFe12O19-SiO2-CaO-Na2O-P2O5 glass system. The ferrimagnetic BaFe12O19 was first prepared using a simple mixed oxide method, where the oxide precursors of 45S5 bioglass were initially mixed and then melted to form glass. The devitrification of Na3Ca6(PO4)5 and Fe3O4 was observed in all of the quenched glass samples. The glass samples were then subjected to a heat treatment schedule for further crystallization. It was found that the small traces of BaFe12O19 phases started to crystallize in high BF content samples of 20 and 40 wt%. These samples also exhibited good magnetic properties comparable to that of other magnetic glass-ceramics. The bioactivity of the BF glass-ceramics improved with increasing BF content as was evident by the formation of bone-like apatite layers on the surface of all of the glass-ceramics after soaking in SBF for 14 days. The results support the use of these bioactive glass-ceramics for hyperthermia treatment within the human body.

  19. Influence of local structural disorders on spectroscopic properties of multi-component CaF2-Bi2O3-P2O5-B2O3 glass ceramics with Cr2O3 as nucleating agent

    NASA Astrophysics Data System (ADS)

    Suresh, S.; Narendrudu, T.; Yusub, S.; Suneel Kumar, A.; Ravi Kumar, V.; Veeraiah, N.; Krishna Rao, D.

    2016-01-01

    Multi-component CaF2-Bi2O3-P2O5-B2O3 glasses doped with different concentrations of Cr2O3 were crystallized through heat treatment. The prepared glass ceramic samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and differential thermal analysis (DTA). Spectroscopic studies viz., optical absorption, Fourier transform infrared (FTIR), Raman and electron paramagnetic resonance (EPR) were carried out. The XRD, SEM and DTA studies indicated that the samples contain different crystalline phases. Results of optical absorption and EPR studies pointed out the gradual conversion of chromium ions from Cr3 + state to Cr6 + state with an increase of Cr2O3 content from 0.1 to 0.5 mol%. The results of FTIR, Raman and EPR studies revealed that Cr6 + ions participate in the glass network in tetrahedral positions and seemed to increase the polymerization of the glass ceramics. The quantitative analysis of results of the spectroscopic studies further indicated that the glasses crystallized with low concentration of Cr2O3 are favourable for solid state laser devices.

  20. Effects of sodium and potassium ions on a novel SeO2-B2O3-SiO2-P2O5-CaO bioactive system

    NASA Astrophysics Data System (ADS)

    Trandafir, D. L.; Ponta, O.; Ciceo-Lucacel, R.; Simon, V.

    2015-01-01

    The study is focused on Na2O and/or K2O influence on a new sol-gel derived SeO2-B2O3-SiO2-P2O5-CaO bioactive system. The structural changes induced by Na2O and/or K2O addition were correlated with the samples behavior in simulated biological media. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the structure and the type of the chemical bonds. The morphology of the samples was characterized through scanning electron microscopy (SEM). XRD results pointed out a prevalent vitreous structure with an incipient hydroxyapatite (HA) crystalline phase. FTIR results revealed a complex network consisting of silicate, phosphate and borate units, as well as the development of both A- and B-type of carbonate-substituted HA. The bioactivity of the samples was tested in vitro following the evolution of the apatite layers self-assembled on the samples surface in simulated body fluid. Their biocompatibility was investigated after samples surface functionalization with protein. The results indicate that sodium and potassium addition improves the biocompatibility by enhancement of protein adherence on samples surface and without to prevent the samples bioactivity.

  1. Magnetic bioactive glass ceramic in the system CaO-P2O5-SiO2-MgO-CaF2-MnO2-Fe2O3 for hyperthermia treatment of bone tumor.

    PubMed

    Li, Guangda; Feng, Shuying; Zhou, Dali

    2011-10-01

    Magnetic bioactive glass ceramic (MG) in the system CaO-SiO(2)-P(2)O(5)-MgO-CaF(2)-MnO(2)-Fe(2)O(3) for hyperthermia treatment of bone tumor was synthesized. The phase composition was investigated by XRD. The magnetic property was measured by VSM. The in vitro bioactivity was investigated by simulated body fluid (SBF) soaking experiment. Cell growth on the surface of the material was evaluated by co-culturing osteoblast-like ROS17/2.8 cells with materials for 7 days. The results showed that MG contained CaSiO(3) and Ca(5)(PO(4))(3)F as the main phases, and MnFe(2)O(4) and Fe(3)O(4) as the magnetic phases. Under a magnetic field of 10,000 Oe, the saturation magnetization and coercive force of MG were 6.4 emu/g and 198 Oe, respectively. After soaking in SBF for 14 days, hydroxyapatite containing CO(3)(2-) was observed on the surface of MG. The experiment of co-culturing cells with material showed that cells could successfully attach and well proliferate on MG. PMID:21870083

  2. Influence of local structural disorders on spectroscopic properties of multi-component CaF2-Bi2O3-P2O5-B2O3 glass ceramics with Cr2O3 as nucleating agent.

    PubMed

    Suresh, S; Narendrudu, T; Yusub, S; Suneel Kumar, A; Ravi Kumar, V; Veeraiah, N; Krishna Rao, D

    2016-01-15

    Multi-component CaF2-Bi2O3-P2O5-B2O3 glasses doped with different concentrations of Cr2O3 were crystallized through heat treatment. The prepared glass ceramic samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and differential thermal analysis (DTA). Spectroscopic studies viz., optical absorption, Fourier transform infrared (FTIR), Raman and electron paramagnetic resonance (EPR) were carried out. The XRD, SEM and DTA studies indicated that the samples contain different crystalline phases. Results of optical absorption and EPR studies pointed out the gradual conversion of chromium ions from Cr(3+) state to Cr(6+) state with an increase of Cr2O3 content from 0.1 to 0.5mol%. The results of FTIR, Raman and EPR studies revealed that Cr(6+) ions participate in the glass network in tetrahedral positions and seemed to increase the polymerization of the glass ceramics. The quantitative analysis of results of the spectroscopic studies further indicated that the glasses crystallized with low concentration of Cr2O3 are favourable for solid state laser devices. PMID:26318703

  3. Effect of ZrO(2) additions on the crystallization, mechanical and biological properties of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics.

    PubMed

    Li, H C; Wang, D G; Meng, X G; Chen, C Z

    2014-06-01

    A series of ZrO(2) doped MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics were obtained by sintering method. The crystallization behavior, phase composition, morphology and structure of glass-ceramics were characterized. The bending strength, elastic modulus, fracture toughness, micro-hardness and thermal expansion coefficient (TEC) of glass-ceramics were investigated. The in vitro bioactivity and cytotoxicity tests were used to evaluate the bioactivity and biocompatibility of glass-ceramics. The sedimentation mechanism and growth process of apatites on sample surface were discussed. The results showed that the mainly crystalline phases of glass-ceramics were Ca(5)(PO4)3F (fluorapatite) and β-CaSiO(3). (β-wollastonite). m-ZrO(2) (monoclinic zirconia) declined the crystallization temperatures of glasses. t-ZrO(2) (tetragonal zirconia) increased the crystallization temperature of Ca(5)(PO4)(3)F and declined the crystallization temperature of β-CaSiO(3). t-ZrO(2) greatly increased the fracture toughness, bending strength and micro-hardness of glass-ceramics. The nanometer apatites were induced on the surface of glass-ceramic after soaking 28 days in SBF (simulated body fluid), indicating the glass-ceramic has good bioactivity. The in vitro cytotoxicity test demonstrated the glass-ceramic has no toxicity to cell. PMID:24780435

  4. Sol-gel Synthesis and Electrospraying of Biodegradable (P2O5)55-(CaO)30-(Na2O)15 Glass Nanospheres as a Transient Contrast Agent for Ultrasound Stem Cell Imaging

    PubMed Central

    Gambhir, Sanjiv S.; Vermesh, Ophir; Kim, Hae-Won; Knowles, Jonathan C.

    2015-01-01

    Ultrasound imaging is a powerful tool in medicine because of the millisecond temporal resolution and sub-millimeter spatial resolution of acoustic imaging. However, the current generation of acoustic contrast agents is primarily limited to vascular targets due to their large size. Nano-size particles have the potential to be used as a contrast agent for ultrasound molecular imaging. Silica-based nanoparticles have shown promise here, however their slow degradation rate may limit their applications as a contrast agent. Phosphate-based glasses are an attractive alternative with controllable degradation rate and easily metabolized degradation components in the body. In this study, biodegradable P2O5-CaO-Na2O phosphate-based glass nanospheres (PGNs) were synthesized and characterized as contrast agents for ultrasound imaging. The structure of the PGNs was characterised using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), 31P nuclear magnetic resonance (31P MAS-NMR), and Fourier transform infrared (FTIR) spectroscopy. The SEM images indicated a spherical shape with a diameter size range of 200-500 nm. The XRD, 31P NMR and FTIR results revealed the amorphous and glassy nature of PGNs that consisted of mainly Q1 and Q2 phosphate units. We used this contrast to label mesenchymal stem cells and determined in vitro and in vivo detection limits of 5 and 9 μg/mL, respectively. Cell counts down to 4000 could be measured with ultrasound imaging with no cytoxicity at doses needed for imaging. Importantly, ion release studies confirmed these PGNs biodegrade into aqueous media with degradation products that can be easily metabolized in the body. PMID:25625373

  5. Optical Properties and Photoactivity of The Pigmentary TiO2 Doped with P2O5, K2O, Al2O3 and Sb2O3

    NASA Astrophysics Data System (ADS)

    Gle?, M.; Grzmil, B.

    2011-05-01

    The influence of the increasing content of antimony calculated to Sb2O3 (0.08-0.57 mol%) with the constant amount of the other additives (calculated to P2O5, K2O, Al2O3) on the optical properties and photostability of doped rutile has been investigated. The properties of the obtained TiO2-PKAlSb samples were compared to the commercial TiO2-PKAl composition. The starting material was the concentrated suspension of technical-grade hydrated titanium dioxide (HTD). The dopant agents' solutions were introduced to HTD. Prepared samples were calcined with gradually increasing process temperature. The XRD analysis was used to determine the rutile content in the TiO2 samples. Optical properties of modified titanium dioxide have been determined spectrophotometrically by measuring the colour in the white (brightness, white tone) and grey system (relative lightening power, grey tone). Photostability was characterized by the white lead-glycerin test with UV-Vis light. It was observed that with the increasing content of antimony in rutile TiO2, doped with phosphates, potassium and aluminium, the brightness and grey tone were increasing but white tone decreased. The changes of the relative lightening power values were insignificant. Comparing the samples of TiO2-PKAlSb with the TiO2-PKAl composition it was observed that titanium dioxide doped with antimony had better white and grey tone. The increasing Sb2O3 content in the TiO2 caused the improvement of the photostability.

  6. Influence of strontium on structure, sintering and biodegradation behaviour of CaO-MgO-SrO-SiO2-P2O5-CaF2 glasses

    SciTech Connect

    Goel, Ashutosh; Rajagopal, Raghu R.; Ferreira, Jose M.

    2011-11-01

    The present study investigates the influence of SrO on structure, apatite forming ability, physico-chemical degradation and sintering behaviour of melt-quenched bioactive glasses with composition: mol.% (36.07 – x) CaO – x SrO - 19.24 MgO – 5.61 P2O5 – 38.49 SiO2 – 0.59 CaF2, where x varies between 0 – 10. The detailed structural analysis of glasses has been made by infra red spectroscopy (FTIR) and magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR). Silicon was predominantly present as Q2 (Si) species while phosphorus was found in orthophosphate type environment in all the investigated glasses. The apatite forming ability of glasses was investigated by immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 h – 7 days. While increasing Sr2+/Ca2+ ratio in glasses did not affect the structure of glasses significantly, their apatite forming ability was decreased considerably. Further, physico-chemical degradation of glasses has been studied in accordance with ISO 10993-14 “Biological evaluation of medical devices – Part 14: Identification and quantification of degradation products from ceramics” in Tris HCl and citric acid buffer and the possible implications of ion release profile from glasses in different solutions has been discussed. The addition of strontium in glasses led to a 7-fold decrease in chemical degradation of glasses in Tris-HCl. The sintering of glass powders rendered glass-ceramics (GCs) with varying degree of crystallinity and good flexural strength (98-131 MPa) where the mechanical properties depend on the nature and amount of crystalline phases present in GCs.

  7. Ionic conductivity of mixed glass former 0.35Na(2)O + 0.65[xB(2)O(3) + (1 - x)P(2)O(5)] glasses.

    PubMed

    Christensen, Randilynn; Olson, Garrett; Martin, Steve W

    2013-12-27

    The mixed glass former effect (MGFE) is defined as a nonlinear and nonadditive change in the ionic conductivity with changing glass former fraction at constant modifier composition between two binary glass forming compositions. In this study, mixed glass former (MGF) sodium borophosphate glasses, 0.35Na2O + 0.65[xB2O3 + (1 - x)P2O5], 0 ≤ x ≤ 1, have been prepared, and their sodium ionic conductivity has been studied. The ionic conductivity exhibits a strong, positive MGFE that is caused by a corresponding strongly negative nonlinear, nonadditive change in the conductivity activation energy with changing glass former content, x. We describe a successful model of the MGFE in the conductivity activation energy terms of the underlying short-range order (SRO) phosphate and borate glass former structures present in these glasses. To do this, we have developed a modified Anderson-Stuart (A-S) model to explain the decrease in the activation energy in terms of the atomic level composition dependence (x) of the borate and phosphate SRO structural groups, the Na(+) ion concentration, and the Na(+) mobility. In our revision of the A-S model, we carefully improve the treatment of the cation jump distance and incorporate an effective Madelung constant to account for many body coulomb potential effects. Using our model, we are able to accurately reproduce the composition dependence of the activation energy with a single adjustable parameter, the effective Madelung constant, that changes systematically with composition, x, and varies by no more than 10% from values typical of oxide ceramics. Our model suggests that the decreasing columbic binding energies that govern the concentration of the mobile cations are sufficiently strong in these glasses to overcome the increasing volumetric strain energies (mobility) caused by strongly increasing glass-transition temperatures combined with strongly decreasing molar volumes of these glasses. The dependence of the columbic binding energy term on the relative high-frequency dielectric permittivity suggests that the increased polarizability of the bridging oxygens connecting SRO tetrahedral boron units to phosphorus units causes further charge delocalization away from the negatively charged tetrahedral boron units, leading to a lowering of the charge density, and is the underlying cause of the MGFE. PMID:24295052

  8. Bioactivity and cell proliferation in radiopaque gel-derived CaO-P2O5-SiO2-ZrO2 glass and glass-ceramic powders.

    PubMed

    Montazerian, Maziar; Yekta, Bijan Eftekhari; Marghussian, Vahak Kaspari; Bellani, Caroline Faria; Siqueira, Renato Luiz; Zanotto, Edgar Dutra

    2015-10-01

    In this study, 10 mol% ZrO2 was added to a 27CaO-5P2O5-68SiO2 (mol%) base composition synthesized via a simple sol-gel method. This composition is similar to that of a frequently investigated bioactive gel-glass. The effects of ZrO2 on the in vitro bioactivity and MG-63 cell proliferation of the glass and its derivative polycrystalline (glass-ceramic) powder were investigated. The samples were characterized using thermo-gravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled to energy dispersive X-ray spectroscopy (EDS). Release of Si, Ca, P and Zr into simulated body fluid (SBF) was determined by inductively coupled plasma (ICP). Upon heat treatment at 1000 °C, the glass powder crystallized into an apatite-wollastonite-zirconia glass-ceramic powder. Hydroxycarbonate apatite (HCA) formation on the surface of the glass and glass-ceramic particles containing ZrO2 was confirmed by FTIR and SEM. Addition of ZrO2 to the base glass composition decreased the rate of HCA formation in vitro from one day to three days, and hence, ZrO2 could be employed to control the rate of apatite formation. However, the rate of HCA formation on the glass-ceramic powder containing ZrO2 crystal was equal to that in the base glassy powder. Tests with a cultured human osteoblast-like MG-63 cells revealed that the glass and glass-ceramic materials stimulated cell proliferation, indicating that they are biocompatible and are not cytotoxic in vitro. Moreover, zirconia clearly increased osteoblast proliferation over that of the Zr-free samples. This increase is likely associated with the lower solubility of these samples and, consequently, a smaller variation in the media pH. Despite the low solubility of these materials, bioactivity was maintained, indicating that these glassy and polycrystalline powders are potential candidates for bone graft substitutes and bone cements with the special feature of radiopacity. PMID:26117775

  9. Measurements of defect structures by positron annihilation lifetime spectroscopy of the tellurite glass TeO2-P2O5-ZnO-LiNbO3 doped with ions of rare earth elements: Er3+, Nd3+ and Gd3+

    NASA Astrophysics Data System (ADS)

    Golis, E.; Yousef, El. S.; Reben, M.; Kotynia, K.; Filipecki, J.

    2015-12-01

    The objective of the study was the structural analysis of the TeO2-P2O5-ZnO-LiNbO3 tellurite glasses doped with ions of the rare-earth elements: Er3+, Nd3+ and Gd3+ based on the PALS (Positron Annihilation Lifetime Spectroscopy) method of measuring positron lifetimes. Values of positron lifetimes and the corresponding intensities may be connected with the sizes and number of structural defects, such as vacancies, mono-vacancies, dislocations or pores, the sizes of which range from a few angstroms to a few dozen nanometres. Experimental positron lifetime spectrum revealed existence of two positron lifetime components ?1 and ?2. Their interpretation was based on two-state positron trapping model where the physical parameters are the annihilation velocity and positron trapping rate.

  10. Chemical durability and Structural approach of the glass series (40-y) Na2O-yFe2O3-5Al2O3-55P2O5-by IR, X-ray diffraction and Mössbauer Spectroscopy

    NASA Astrophysics Data System (ADS)

    Aqdim, S.; Sayouty, El H.; Elouad, B.; Greneche, J. M.

    2012-02-01

    The relationship between the composition and structure for the glasses of general composition (40-y)Na2O-yFe2O3-5Al2O3-55P2O5 (5<=y<=20), has been studied. The chemical durability and density of these glasses increase with increasing Fe2O3 content. The dissolution rate (DR), calculated from the weight loss in distilled water at 90°C for up to 20 days was ? 3.10-9 g/cm2/mn which is 30 times lower than that of window glass. The structure and valence states of the iron ions in the glasses were investigated using, X-ray diffraction, 57Fe Mössbauer spectrometry, potentiometric analysis, and infrared spectroscopy. Both Mössbauer spectrometry and potentiometric analysis allow to estimate both Fe2+ and Fe3+ contents in all these glasses. X-ray diffraction indicates that the local structure of iron phosphate glasses is related to the short range structures of NaFeP2O7. Infrared spectra indicate the formation of P-O-Fe bonds in the pyrophosphate glasses that replace P-O-Na bonds. The presence of a small content of Al2O3 in the glass seems to play a role as a network modifier. The addition of Fe2O3 to Al2O3 in phosphate glasses favours the enhancement of the formation of pyrophosphate units because iron ions have stronger effect on the depolymerization of metaphosphate chains than the aluminium ions. Finally, the I.R spectra indicate that the presence of P-O-Fe bands of these glasses containing more than 15 mol%Fe2O3 is consistent with their good chemical durability.

  11. Biocompatibility property of 100% strontium-substituted SiO2 -Al2 O3 -P2 O5 -CaO-CaF2 glass ceramics over 26 weeks implantation in rabbit model: Histology and micro-Computed Tomography analysis.

    PubMed

    Basu, Bikramjit; Sabareeswaran, A; Shenoy, S J

    2015-08-01

    One of the desired properties for any new biomaterial composition is its long-term stability in a suitable animal model and such property cannot be appropriately assessed by performing short-term implantation studies. While hydroxyapatite (HA) or bioglass coated metallic biomaterials are being investigated for in vivo biocompatibility properties, such study is not extensively being pursued for bulk glass ceramics. In view of their inherent brittle nature, the implant stability as well as impact of long-term release of metallic ions on bone regeneration have been a major concern. In this perspective, the present article reports the results of the in vivo implantation experiments carried out using 100% strontium (Sr)-substituted glass ceramics with the nominal composition of 4.5 SiO2 -3Al2 O3 -1.5P2 O5 -3SrO-2SrF2 for 26 weeks in cylindrical bone defects in rabbit model. The combination of histological and micro-computed tomography analysis provided a qualitative and quantitative understanding of the bone regeneration around the glass ceramic implants in comparison to the highly bioactive HA bioglass implants (control). The sequential polychrome labeling of bone during in vivo osseointegration using three fluorochromes followed by fluorescence microscopy observation confirmed homogeneous bone formation around the test implants. The results of the present study unequivocally confirm the long-term implant stability as well as osteoconductive property of 100% Sr-substituted glass ceramics, which is comparable to that of a known bioactive implant, that is, HA-based bioglass. PMID:25303146

  12. Structural studies of mixed glass former 0.35Na2O + 0.65[xB2O3 + (1 - x)P2O5] glasses by Raman and 11B and 31P magic angle spinning nuclear magnetic resonance spectroscopies.

    PubMed

    Christensen, Randilynn; Olson, Garrett; Martin, Steve W

    2013-02-21

    The mixed glass former (MGF) effect (MGFE) is defined as a nonlinear and nonadditive change in the ionic conductivity with changing glass former composition at constant modifier composition. In this study, sodium borophosphate 0.35Na(2)O + 0.65[xB(2)O(3) + (1 - x)P(2)O(5)], 0 ? x ? 1, glasses which have been shown to exhibit a positive MGFE have been prepared and examined using Raman and (11)B and (31)P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopies. Through examination of the short-range order (SRO) structures found in the ternary glasses, it was determined that the minority glass former, B for 0.1 ? x ? 0.7 and P for 0.7 ? x ? 0.9, is "overmodified" and contains more Na(+) ions than would be expected from simple linear mixing of the binary sodium borate, x = 1, and sodium phosphate, x = 0, glasses, respectively. Changes in the intermediate range order (IRO) structures were suggested by changes in the NMR spectral chemical shifts and Raman spectra wavenumber shifts over the full composition range x in the Raman and MAS NMR spectra. The changes observed in the chemical shifts of (31)P MAS NMR spectra with x are found to be too large to be caused solely by changing sodium modification of the phosphate SRO structural groups, and this indicates that internetwork bonding between phosphorus and boron through bridging oxygens (BOs), P-O-B, must be a major contributor to the IRO structure of these glasses. While not fully developed, a first-order thermodynamic analysis based upon the Gibbs free energies of formation of the various SRO structural units in this system has been developed and can be used to account for the preferential formation of tetrahedral boron groups, B(4), by the reaction of B(3) with P(2) groups to form B(4) and P(3) groups, respectively, where the superscript denotes the number of BOs on these units, in these glasses. This preference for B(4) units appears to be a predominate cause of the changing modifier to glass former ratio with composition x in these ternary MGF glasses and appears to be associated with the large negative value of the Gibbs free energy of formation of this group. PMID:23281937

  13. Melt densities for leucogranites and granitic pegmatites: Partial molar volumes for SiO 2, Al 2O 3, Na 2O, K 2O, Li 2O, Rb 2O, Cs 2O, MgO, CaO, SrO, BaO, B 2O 3, P 2O 5, F 2O -1, TiO 2, Nb 2O 5, Ta 2O 5, and WO 3

    NASA Astrophysics Data System (ADS)

    Knoche, R.; Dingwell, D. B.; Webb, S. L.

    1995-11-01

    The densities and thermal expansivities of thirty-eight haplogranitic silicate melts have been experimentally determined. The compositions represent the additions of approximately 5, 10, and 20 wt% of selected oxide components Al 2O 3, Na 2O, K 2O, Li 2O, Rb 2O, Cs 2O, MgO, CaO, SrO, BaO, TiO 2, Nb 2O 5, Ta 2O 5, and WO 3 to a base melt of haplogranitic (HPG8) composition. The densities of melts have been obtained by a combination of scanning dilatometry and room temperature Archimedean density determinations together with scanning calorimetry. The thermal expansivities were obtained by a combination of scanning calorimetry and scanning dilatometry. The results of the density and expansivity determinations for the melts are fit to a multicomponent linear least squares regression of molar volume vs. molar composition. The resulting partial molar volumes of the molten oxides are reported for a reference temperature of 750°C. The multicomponent linear least squares regression yields a description of the database with a root mean squared deviation of 0.3%. The fit to these new partial molar volume data includes our previous data for B 2O 3, P 2O 5, and F 2O -1-bearing haplogranitic melts. The partial molar volumes of the oxides vary from 10.53 ± 0.29 cm 3 mole -1 for MgO to 69.09 ± 1.82 cm 3 mol -1 for P 2O 5. Compared on the basis of one oxygen per mole they range from 10.53 ± 0.29 cm 3 mol -1 (MgO) to 55.38 ± 1.69 cm 3 mol -1 (Cs 2O). The present data, taken together with an estimate of the partial molar volume of water in these melts (13.1 ± 1.3 cm 3 mol -1) are recommended to be used to calculate the low pressure densities of leucogranitic and pegmatitic melts.

  14. Spectroscopic properties of MO-WO_3-P_2O_5: Hoboldmath 3+ glasses

    NASA Astrophysics Data System (ADS)

    Subbalakshmi, P.; Raghavaiah, B. V.; Balaji Rao, R.; Veeraiah, N.; Babu, P.; Jayasankar, C. K.

    2004-06-01

    ESR, IR, optical absorption and photoluminescence spectra of Ho3+ doped tungsten phosphate glasses modified with three different modifier oxides viz., PbO, ZnO and CaO have been studied. The ESR spectral studies indicate tungsten ions are present in W5+ state in all the three glasses with the highest concentration in CaO modified glasses. From the measured intensities of various absorption bands of these glasses, the Judd-Ofelt (JO) parameters ?_2, ?4 and ?6 have been evaluated. The JO theory could successfully be applied to characterise the absorption and luminescence spectra of these glasses. From this theory various radiative properties like radiative transition probabilities, A, branching ratios, ?_r, the radiative lifetimes, ?_R, and the emission cross-sections, ?^E, for various emission levels of Ho3+ in these glasses have been determined and reported. An attempt has also been made to throw some light on the environment of Ho3+ ions in all the three glasses.

  15. Excitation light source dependence of emission in Sn2+-Ce3+ codoped ZnO-P2O5 glasses

    NASA Astrophysics Data System (ADS)

    Masai, Hirokazu; Hino, Yusuke; Yanagida, Takayuki; Fujimoto, Yutaka; Fukuda, Kentaro; Yoko, Toshinobu

    2013-08-01

    Correlation between excitation light source and the emission property of Sn2+-Ce3+ co-doped zinc phosphate glasses is examined. Although photoluminescence (PL) peaks of both Sn2+ and Ce3+ shifted with increasing amount of Ce3+, there was little energy resonance between Sn2+ and Ce3+ emission centers. On the other hand, radioluminescence (RL) spectra excited by X-ray was independent of the Ce concentration, indicating that emission was mainly observed from Sn2+ emission center. It is expected that energy relaxation process in a RL preferentially occurs in an ns2-type emission center that possesses high transition probability of the excited state in the higher energy region.

  16. Transport properties of PbO-P2O5-ZnO-Li2O glass system

    NASA Astrophysics Data System (ADS)

    Lakshmikantha, R.; Rajaramakrishna, R.; Ayachit, N. H.; Anavekar, R. V.

    2012-06-01

    The electrical conductivity of Li+ ion conducting lead zinc phosphate glasses have been carried out both as a function of temperature and frequency in the temperature range 458-510K and over frequencies 40 Hz to 10 MHz. The dc conductivities show Arrhenius behavior and show compositional dependence. The σ decreases with increase in Li2O content. The ac conductivity behavior has been analyzed using Almond-West power law using a single exponent. The exponent 's' obtained from the power law fits is found to have values ranging from 0.74 - 0.80 in these glasses and shows moderate temperature dependence, which is attributed to high degree of modification in the glass network.

  17. Phase equilibria in the P(2)O(5)-CaO-CaF(2)-NaF-H(2)O quinary system and the formation of apatite

    NASA Astrophysics Data System (ADS)

    Martin, Roger Isaac

    Phase equilibria among calcium phosphates in the Hsb3POsb4-Ca(OH)sb2-Hsb2O ternary system were determined as a basis for research in the formation of hydroxyapatite, a biomaterial. The acidic portion of the ternary diagram was established. Ca(Hsb2POsb4)sb2 was not stable for temperatures below 100sp°C. The experimental and theoretical dissolution paths of Ca(Hsb2POsb4)sb2{*}Hsb2O were compared. It is possible for the initial dissolution of Ca(Hsb2POsb4)sb2{*}Hsb2O to supersaturate the system with respect to hydroxyapatite because Ca(Hsb2POsb4)sb2{*}Hsb2O is "twice" incongruently soluble. Hydroxyapatite composition is variable with a Ca/P ratio ranging from 1.5 to 1.67. Hydroxyapatite formation from acid-base reactions of CaHPOsb4 and Casb4(POsb4)sb2O was investigated for composition at the terminal limits. The total heats-of-reaction (Delta Hsb{r}) were determined to be 261.3 and 320 kJ/mol for the formation of calcium deficient and stoichiometric hydroxyapatite, respectively. Activation energies of 84.7 and 87.4 kJ/mol were calculated for the formation of calcium deficient and stoichiometric hydroxyapatite, respectively. Heats-of-formation (Delta Hsb{f}) for Casb4(POsb4)sb2O and Casb9HPOsb4(POsb4)sb5OH were calculated to be -4764.1 and -1207.7 kJ/mol, respectively. The effects of magnesium on hydroxyapatite formation in vitro from CaHPOsb4 and Casb4(POsb4)sb2O at 37.4sp°C were investigated. Magnesium is a biological agent with 0.78 mM concentrations in blood. Magnesium inhibited nucleation for 1 mM concentrations and above for a 5 liquid-to-solids ratio. However, a 5 mM concentration of MgClsb2 slightly accelerated the growth rate. The activity of magnesium is approximately 6% of its concentration. Therefore the inorganic chemical activity of magnesium may not significantly inhibit the formation of bioapatites. Phase equilibria in the Psb2Osb5-CaO-CaFsb2-Hsb2O system at 37.4sp°C was determined and dental fluorosis explained. Fluoroapatite dissolves incongruently with respect to CaFsb2. Therefore, treatment of dentin and tooth enamel with fluoride leads to the formation of fluorosis because the solution first becomes supersaturated with CaFsb2. Based on thermodynamics, the conversion of hydroxyapatite to fluoroapatite cannot be a single exchange of fluoride for hydroxl. CaHPOsb4 hydrolysis and equilibrium in sodium fluoride solutions at 37.4sp°C reveal the added effect of sodium on the system. Sodium phosphate species form and overcome CaHPOsb4 incongruency. At initial NaF concentrations greater than 150 mM, NaF species rise and may overcome fluoroapatite incongruency.

  18. The effect of WO3 dopant on the structural and optical properties of ZnO-P2O5 glass and the effect of gamma irradiation

    NASA Astrophysics Data System (ADS)

    Abdelghany, A. M.; Hammad, Ahmed H.

    2015-02-01

    Zinc phosphate glasses doped with different ratios of tungsten trioxide were prepared. Optical and infrared absorption spectra were investigated before and after subjecting the glasses to 80 kGy gamma ray dose. The base undoped zinc phosphate glass shows strong and broad UV absorption band centered at about 240 nm but with no visible bands. The WO3-doped glasses reveal the same UV absorption bands beside extra three bands at 330, 380 and 575 nm which are related to the presence tungsten ions in the pentavalent state. Infrared absorption spectra show characteristic variable phosphate groups with limited variations when introducing WO3 in the doping level up to 0.75%. Electron spin resonance measurements of the selected high doped tungsten glass indicate that mixed penta- and hexa-valent states of the tungsten ions and on gamma irradiation the pentavalent increases. The result supports the optical absorption after gamma irradiation which involves photochemical reactions in the UV region and the transformation of some W6+ to W5+ by absorbing electrons during the irradiation process.

  19. Partitioning of Nb, Mo, Ba, Ce, Pb, Th and U between immiscible carbonate and silicate liquids: Evaluating the effects of P2O5,F, and carbonate composition

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Walker, D.

    1993-01-01

    Previously we have reported carbonate liq./silicate liq. partition coefficients (D) for a standard suite of trace elements (Nb, Mo, Ba, Ce, Pb, Th, and U) and Ra and Pa as well. In brief, we have found that immiscible liquid partitioning is a strong function of temperature. As the critical temperature of the carbonate-silicate solvus is approached, all partition coefficients approach unity. Additionally, for the overwhelming majority of the partitioning elements, InD is a linear function of 'ionic field strength,' z/r, where z is the charge of the partitioned cation and r is its ionic radius.

  20. Fertilization ratios of N-P2O5-K2O for Tifton 85 bermudagrass on two coastal plain soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bermudagrass [Cynodon dactylon (L.) Pers.] cultivar Tifton 85 is widely grown throughout the southeastern United States and many other countries for forage production. Because Tifton 85 is actually a hybrid between C. dactylon and C. nlemfuensis, it may not respond to fertilization in the same way ...

  1. Reflexión bioética sobre el uso de organismos genéticamente modificados

    PubMed Central

    Yunta, Eduardo Rodríguez

    2011-01-01

    El presente artículo reflexiona desde los 4 principios de la bioética el uso comercial de organismos genéticamente modificados. Se cuestiona fundamentalmente la falta de transferencia de tecnología entre el mundo desarrollado y en desarrollo y el que el presente sistema de patentamiento de organismos vivos modificados fomenta intereses comerciales y no da debida importancia al desarrollo sostenible de la agricultura y ganadería en los países en desarrollo, donde más se necesita. Se reflexiona sobre la importancia que tiene evaluar los riesgos antes de introducirse en el mercado organismos genéticamente modificados y la necesidad de regulación en los países. PMID:21927675

  2. Diopside (CaO-MgO-2SiO2)-fluorapatite (9CaO-3P2O5-CaF2) glass-ceramics: Potential materials for bone tissue engineering

    SciTech Connect

    Kansal, Ishu; Goel, Ashutosh; Tulyaganov, Dilshat U.; Pascual, Maria J.; Lee, Hye-Young; Kim, Hae-Won; Ferreira, Jose M.

    2011-08-18

    Glass-ceramics in the diopside (CaMgSi2O6) - fluorapatite [Ca5(PO4)3F] system are potential candidates for restorative dental and bone implant materials. In the present study, a series of glasses along diopside - fluorapatite binary system have been prepared with varying diopside/fluorapatite ratios for their potential applications in bone tissue engineering. The glasses were obtained from compositions with fluorapatite contents varying between 0-40 wt.%. The sintering ability and crystallization kinetics of as obtained amorphous glasses have been studied through hot-stage microscopy (HSM) and differential thermal analysis (DTA), respectively while crystalline phase evolution in sintered GCs has been followed by X-ray diffraction (XRD) adjoined with Rietveld-R.I.R. technique and scanning electron microscopy (SEM). Further, biodegradation and apatite forming ability of glass-ceramics were investigated by immersion of glass-ceramic discs in simulated body fluid (SBF) solution while chemical degradation and weight loss of glass-ceramics were studied by immersion in Tris-HCl in accordance with standard ISO 10993-14. The addition of fluorapatite (10-25 wt.%) in diopside glass system significantly enhanced the sintering ability of glass-ceramics and improved their apatite forming ability along with their biodegradation behaviour. Moreover, the in vitro cellular responses to glass-ceramics showed good cell viability and significant stimulation of osteoblastic differentiation, suggesting the possible use of the glass-ceramics for bone regeneration.

  3. Equilibrium relations in the system TiO2/V2O5/P2O5 and crystal structure of a NASICON-related vanadyl(V) titanium(IV) phosphate

    NASA Astrophysics Data System (ADS)

    Titlbach, Sven; Hoffbauer, Wilfried; Glaum, Robert

    2012-12-01

    Vanadyl(V)-titanium-orthophosphate (VVO)TiIV6(PO4)9 is formed by solid state reactions in the temperature range 525≤ϑ≤780 °C. At higher temperature decomposition into V2O5 and the hitherto unknown solid solution Ti(P1-xVx)2O7 (0≤x≤0.23; 0.30≤x≤0.43) is observed. The process of phase formation has been monitored by MAS-NMR (31P, 51V) spectroscopy. Equilibrium phase relations in the quaternary system TiO2/VO2.5/PO2.5 have been determined. A structure analysis from X-ray single-crystal data (P63/m (No. 176), Z=2; a=8.4438(3) Å, c=22.215(1) Å, 14 independent atoms, 87 variables, 2066 unique reflections, R1=0.032, wR2=0.084) shows the relationship of (VVO)TiIV6(PO4)9 to the NASICON structure family. In marked contrast to the other members of this family [TiIV2O9] double-octahedra and strongly distorted tetrahedral [(VV=O)O3] groups are observed besides isolated [TiIVO6] octahedra and phosphate tetrahedra. The structure model is in agreement with the results from MAS-NMR (31P, 51V) spectroscopy.

  4. Optical character of Er 3+/Yb 3+ co-doped P 2O 5-CaO-Na 2O-Al 2O 3-AgO phosphate glass

    NASA Astrophysics Data System (ADS)

    Ming, Chengguo; Song, Feng; Yu, Yin; Zhang, Gong; Wang, Qingru; Yu, Hua; Sun, Tongqing; Tian, Jianguo

    2011-04-01

    The up-conversion (UC) and near infrared (NIR) luminescence of Er3+/Yb3+ co-doped phosphate glass are investigated. In the UC emission range, the 523 nm, 546 nm green emissions and the 659 nm red emission are observed. With the increasing pump power, the intensity ratios of I523/I659, I546/I659 and I523/I546 increase gradually. The phenomenon is reasonably interpreted by theoretical analysis based on steady state rate equations. The emission cross section of the infrared emission at 1546 nm is larger (about 6.7 × 10- 21 cm2), which is suitable for making fiber amplifier.

  5. Structural analysis of xSrO-(50 - x)CaO-50P2O5 glasses with x=0, 5, or 10 mol% for potential use in a local delivery system for osteomyelitis treatment.

    PubMed

    Comeau, P A; Filiaggi, M J

    2016-01-01

    The introduction of ions into a local delivery matrix is one method of managing degradation and subsequent release of the incorporated therapeutic agents. Of interest in this study was whether we could modify the structural nature of calcium polyphosphate (CPP) glass and the subsequent therapeutic potential of this local delivery matrix with inclusion of strontium (Sr). We found that adding 10 mol% Sr significantly increased the density and chain length of the glass. There was no significant impact of Sr doping on the subsequent loading of vancomycin into the matrix, or the matrix porosity. The noted differences in structural stability, ion release, and vancomycin release between the un-doped CPP matrices and 10 mol% Sr-doped CPP matrices in vitro are likely a result of a decrease in glass disorder upon Sr addition to the glass and preferential retention of Sr over Ca during matrix degradation. This study has provided further evidence that Sr incorporation may serve to both manipulate antibiotic release from the amorphous CPP matrix and provide a potential source of therapeutic ions for enhanced bone regeneration. PMID:26478355

  6. DESAFÍOS ÉTICOS DE LA INVESTIGACIÓN CON ANIMALES, MANIPULACIÓN GENÉTICA

    PubMed Central

    Yunta, Eduardo Rodríguez

    2012-01-01

    En la investigación con animales existen cuestionamientos éticos tanto en el uso como modelos de enfermedades humanas y requisito previo para ensayos en humanos como en la introducción de modificaciones genéticas. Algunos de estos cuestionamientos son: no representar exactamente la condición humana como modelos, realizar pruebas de toxicidad con grave daño para los animales, alterar su naturaleza mediante modificaciones genéticas, riesgos de la introducción de organismos genéticamente modificados. El uso de animales en investigación para beneficio humano, impone al ser humano la responsabilidad moral de respetarlo, no haciéndoles sufrir innecesariamente, al estar trabajando con seres vivientes y sentientes. PMID:23338641

  7. The Con Test

    ERIC Educational Resources Information Center

    Fletcher, Michael

    2009-01-01

    In this article, the author describes the format of the Con Test, an Australian television game show which followed the same general rules and game play as the UK show PokerFace. At the end of each round a contestant needs to decide whether or not he or she should fold. A contestant needs to know how likely it is that he or she is in last place.…

  8. Nam Con Son Basin

    SciTech Connect

    Tin, N.T.; Ty, N.D.; Hung, L.T.

    1994-07-01

    The Nam Con Son basin is the largest oil and gas bearing basin in Vietnam, and has a number of producing fields. The history of studies in the basin can be divided into four periods: Pre-1975, 1976-1980, 1981-1989, and 1990-present. A number of oil companies have carried out geological and geophysical studies and conducted drilling activities in the basin. These include ONGC, Enterprise Oil, BP, Shell, Petro-Canada, IPL, Lasmo, etc. Pre-Tertiary formations comprise quartz diorites, granodiorites, and metamorphic rocks of Mesozoic age. Cenozoic rocks include those of the Cau Formation (Oligocene and older), Dua Formation (lower Miocene), Thong-Mang Cau Formation (middle Miocene), Nam Con Son Formation (upper Miocene) and Bien Dong Formation (Pliocene-Quaternary). The basement is composed of pre-Cenozoic formations. Three fault systems are evident in the basin: north-south fault system, northeast-southwest fault system, and east-west fault system. Four tectonic zones can also be distinguished: western differentiated zone, northern differentiated zone, Dua-Natuna high zone, and eastern trough zone.

  9. Galaxias australes con núcleo doble

    NASA Astrophysics Data System (ADS)

    Gimeno, G.; Díaz, R.; Carranza, G.

    Se estudia una muestra de galaxias australes con núcleo doble a partir de una búsqueda extensiva en la literatura. Se analizan las características morfológicas, fotométricas y espectroscópicas de la muestra. Para algunas galaxias se han realizado observaciones con el espectrógrafo multifunción (EMF) de la Estación Astrofísica de Bosque Alegre a partir de las cuales se determinaron parámetros cinemáticos.

  10. Trazando la materia oscura con cúmulos globulares

    NASA Astrophysics Data System (ADS)

    Forte, J. C.

    Se describe la estrategia adoptada para mapear la distribución de materia oscura y bariónica en galaxias elípticas cuyos cúmulos globulares están siendo observados con los telescopios VLT y Gemini. Se ejemplifican los resultados con los datos obtenidos en el cúmulo de Fornax.

  11. Ependimoma myxopapilar sacro gigante con osteolisis

    PubMed Central

    Ajler, Pablo; Landriel, Federico; Goldschmidt, Ezequiel; Campero, Álvaro; Yampolsky, Claudio

    2014-01-01

    Objetivo: la presentación de un caso de una paciente con un ependimoma sacro con extensa infiltración y destrucción ósea local. Descripción del caso: una mujer de 53 años acudió a la consulta por dolor lumbosacro y alteraciones sensitivas perineales y esfinterianas. La imágenes por Resonancia Magnética (IRM) y la Tomografía Axial Computada (TAC) mostraron una lesión expansiva gigante a nivel S2-S4 con extensa osteólisis e invasión de tejidos adyacentes. Se realizó una exéresis tumoral completa con mejoría del estatus funcional. La anatomía patológica informó ependimoma mixopapilar. Discusión: la extensión de la resección quirúrgica es el mejor predictor de buen pronóstico. El tratamiento radiante se reserva como opción adyuvante para las resecciones incompletas y recidiva tumoral. La quimioterapia sólo debería utilizarse en casos en que la cirugía y la radioterapia estén contraindicadas. Conclusión: Los ependimomas mixopapilares sacros con destrucción ósea y presentación intra y extradural son muy infrecuentes y deben ser tenidos en cuenta entre los diagnósticos diferenciales preoperatorios. Su resección total, siempre que sea posible, es la mejor alternativa terapéutica. PMID:25165615

  12. The pros and cons of hospital employment.

    PubMed

    Bert, Jack M

    2013-09-01

    The pros and cons of hospital employment vary significantly in today's economic environment. This chapter summarizes the advantages and disadvantages of hospital employment with an emphasis on the critical aspect of formalizing an agreement with the hospital employer to prevent future salary reductions and/or termination. PMID:23924751

  13. InterCon Travel Health: Case B

    ERIC Educational Resources Information Center

    Truman, Gregory E.; Pachamanova, Dessislava A.; Goldstein, Michael A.

    2010-01-01

    InterCon provides services to health insurers of foreign tourists who travel to the United States and Canada. Management wants to implement a new information system that will deal with several operational problems, but it is having difficulty securing the capital resources to fund the system's development. After an initial failure, the chief…

  14. Somatic cell nuclear transfer: pros and cons.

    PubMed

    Sumer, Huseyin; Liu, Jun; Tat, Pollyanna; Heffernan, Corey; Jones, Karen L; Verma, Paul J

    2009-01-01

    Even though the technique of mammalian SCNT is just over a decade old it has already resulted in numerous significant advances. Despite the recent advances in the reprogramming field, SCNT remains the bench-mark for the generation of both genetically unmodified autologous pluripotent stem cells for transplantation and for the production of cloned animals. In this review we will discuss the pros and cons of SCNT, drawing comparisons with other reprogramming methods. PMID:20232594

  15. Experimental and Computational Studies of Carbonyl Diazide (CON6) as a Precursor to Diazirinone (CON2)

    NASA Astrophysics Data System (ADS)

    Esselman, Brian J.; Amberger, Brent K.; Nolan, Alex M.; Woods, R. Claude; McMahon, R. J.

    2011-10-01

    Intrigued by the reported 2005 synthesis of diazirinone (1), we carried out further experimental and theoretical studies aimed at the detailed matrix-isolation and millimeter-wave spectroscopic characterizations of 1. Diazirinone (1) is a peculiar isoconjugate of two very stable molecules and may be of astrochemical interest. Unfortunately, the original reported methods of diazirinone (1) generation did not yield this species, rather its decomposition products. Inspired by a more recent gas phase pyrolysis of CON6 (2) to yield CON2 (1), we proposed a new method of generating CON6 (2) in solution as a precursor of diazirinone (1). This new synthesis may allow us to generate larger quantities of both CON6 and CON2 for investigation by millimeter-wave spectroscopy. We are able to safely generate carbonyl diazide (2) in sufficient yield from the reaction of triphosgene (3) and tetrabutylammonium azide in diethyl ether. This has allowed us to obtain both matrix-isolation and gas phase IR spectra of carbonyl diazide (2). After purification, it has a gas-phase lifetime that allows samples to be useable for up to several weeks. However, it is a shock-sensitive material that must be handled with care to prevent violent decomposition. In order to provide better mechanistic insight into the decomposition of carbonyl diazide (2) to diazirinone (1), we have engaged in a DFT and ab initio computational study. We have found a pathway between the two species via the triplet acylnitrene, CON4, and an oxaziridine CON2 species, but not at sufficiently low energies to allow for the trapping and detection of diazirinone (1). Preliminary millimeter-wave spectra have been obtained from several synthesized and purified samples of CON6 (2). However, the assignment of the spectra lines has been unexpectedly problematic. We have placed several CON6 (2) samples, confirmed by IR spectroscopy at the time of sample loading, into our instrument and obtained two different sets of rotational lines. This rotational puzzle will be investigated further with a significantly upgraded millimeter-wave spectrometer.

  16. 9 CFR 319.301 - Chili con carne with beans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Chili con carne with beans. 319.301 Section 319.301 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Dehydrated Meat Food Products § 319.301 Chili con carne with beans. Chili con carne with beans shall...

  17. Energy Star program benefits Con Edison

    SciTech Connect

    1995-05-01

    Impressed with savings in energy costs achieved after upgrading the lighting and air conditioning systems at its Manhattan headquarters, Home Box Office (HBO) wanted to do more, James Flock, vice president for computer and office systems, contacted Con Edison Co. of New York in March 1991 to determine what the company could do to save money by reducing energy consumed by personal computers. Arthur Kressner, Con Edison Research and Development manager contacted industry organizations and manufacturers for advice, but was told only to shut off computers at night and on weekends. Kressner arranged a series of meetings with IBM and the Electric Power Research Institute (EPRI) to discuss the issue, then approached the U.S. Environmental Protection Agency (EPA), which was designing a program to promote the introduction and use of energy-efficient office equipment. In 1992, the EPA announced the Energy Star program for PCs, enabling manufacturers to display the Energy Star logo on machines meeting program criteria, including the ability to enter a sleep mode in which neither the computer nor monitor consume more than 30 W or electricity. Industry experts estimate national energy consumption by office equipment could double by the year 2000, but Energy Star equipment is expected to improve efficiency and help maintain electric loads.

  18. Cervical disc arthroplasty: Pros and cons

    PubMed Central

    Moatz, Bradley; Tortolani, P. Justin

    2012-01-01

    Background: Cervical disc arthroplasty has emerged as a promising potential alternative to anterior cervical discectomy and fusion (ACDF) in appropriately selected patients. Despite a history of excellent outcomes after ACDF, the question as to whether a fusion leads to adjacent segment degeneration remains unanswered. Numerous US investigational device exemption trials comparing cervical arthroplasty to fusion have been conducted to answer this question. Methods: This study reviews the current research regarding cervical athroplasty, and emphasizes both the pros and cons of arthroplasty as compared with ACDF. Results: Early clinical outcomes show that cervical arthroplasty is as effective as the standard ACDF. However, this new technology is also associated with an expanding list of novel complications. Conclusion: Although there is no definitive evidence that cervical disc replacement reduces the incidence of adjacent segment degeneration, it does show other advantages; for example, faster return to work, and reduced need for postoperative bracing. PMID:22905327

  19. Pros and cons of phage therapy

    PubMed Central

    Loc-Carrillo, Catherine

    2011-01-01

    Many publications list advantages and disadvantages associated with phage therapy, which is the use of bacterial viruses to combat populations of nuisance or pathogenic bacteria. The goal of this commentary is to discuss many of those issues in a single location. In terms of “Pros,” for example, phages can be bactericidal, can increase in number over the course of treatment, tend to only minimally disrupt normal flora, are equally effective against antibiotic-sensitive and antibiotic-resistant bacteria, often are easily discovered, seem to be capable of disrupting bacterial biofilms, and can have low inherent toxicities. In addition to these assets, we consider aspects of phage therapy that can contribute to its safety, economics, or convenience, but in ways that are perhaps less essential to the phage potential to combat bacteria. For example, autonomous phage transfer between animals during veterinary application could provide convenience or economic advantages by decreasing the need for repeated phage application, but is not necessarily crucial to therapeutic success. We also consider possible disadvantages to phage use as antibacterial agents. These “Cons,” however, tend to be relatively minor. PMID:22334867

  20. ProCon - PROteomics CONversion tool.

    PubMed

    Mayer, Gerhard; Stephan, Christian; Meyer, Helmut E; Kohl, Michael; Marcus, Katrin; Eisenacher, Martin

    2015-11-01

    With the growing amount of experimental data produced in proteomics experiments and the requirements/recommendations of journals in the proteomics field to publicly make available data described in papers, a need for long-term storage of proteomics data in public repositories arises. For such an upload one needs proteomics data in a standardized format. Therefore, it is desirable, that the proprietary vendor's software will integrate in the future such an export functionality using the standard formats for proteomics results defined by the HUPO-PSI group. Currently not all search engines and analysis tools support these standard formats. In the meantime there is a need to provide user-friendly free-to-use conversion tools that can convert the data into such standard formats in order to support wet-lab scientists in creating proteomics data files ready for upload into the public repositories. ProCon is such a conversion tool written in Java for conversion of proteomics identification data into standard formats mzIdentML and Pride XML. It allows the conversion of Sequest™/Comet .out files, of search results from the popular and often used ProteomeDiscoverer® 1.x (x=versions 1.1 to1.4) software and search results stored in the LIMS systems ProteinScape® 1.3 and 2.1 into mzIdentML and PRIDE XML. This article is part of a Special Issue entitled: Computational Proteomics. PMID:26182917

  1. A ConA-like lectin from Dioclea guianensis Benth. has antifungal activity against Colletotrichum gloeosporioides, unlike its homologues, ConM and ConA.

    PubMed

    Araújo-Filho, José H; Vasconcelos, Ilka M; Martins-Miranda, Aparecida S; Gondim, Darcy M F; Oliveira, José T A

    2010-04-14

    This study reports on the antifungal activity of Dgui, a ConA-like lectin from Dioclea guianensis seeds. Dgui inhibited conidial germination but not mycelial growth of Colletotrichum gloeosporioides. The lectins ConA and ConM from Canavalia ensiformis and Canavalia maritima, respectively, share high levels of amino acid sequence similarity (>84%) with Dgui and have the same specificity toward glucose/mannose but had no effect on the fungus. Fluorescence microscopy showed that both Dgui and ConM bind to C. gloeosporioides ungerminated conidia. However, Dgui did not bind to C. gloeosporioides germinated conidia and germ tubes and was not inhibitory to mycelial growth. Because only Dgui inhibited germination of the fungus, C. gloeosporioides conidia might have surface-specific germination targets recognized by Dgui but not by its homologues, ConM and ConA. Therefore, Dgui is a candidate for biotechnological approaches for improving the resistance of various nutritionally and commercially important crops that are affected by C. gloeosporioides. PMID:20201549

  2. Games Con Men Play: The Semiosis of Deceptive Interaction.

    ERIC Educational Resources Information Center

    Hankiss, Agnes

    1980-01-01

    Analyzes some of the most frequent deceptive interactions as rendered through case histories of male con artists and their victims taken from police records. Discusses the recurrent elements in both the con-games strategies and victims' way of interpreting those strategies. (JMF)

  3. RoboCon: A general purpose telerobotic control center

    SciTech Connect

    Draper, J.V.; Noakes, M.W.; Schempf, H.; Blair, L.M.

    1997-02-01

    This report describes human factors issues involved in the design of RoboCon, a multi-purpose control center for use in US Department of Energy remote handling applications. RoboCon is intended to be a flexible, modular control center capable of supporting a wide variety of robotic devices.

  4. 9 CFR 319.300 - Chili con carne.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food Products § 319.300 Chili con carne. “Chili con carne” shall contain not less than 40 percent of meat... 25 percent of the meat ingredients under specific declaration on the label. The mixture may...

  5. 9 CFR 319.300 - Chili con carne.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food Products § 319.300 Chili con carne. “Chili con carne” shall contain not less than 40 percent of meat... 25 percent of the meat ingredients under specific declaration on the label. The mixture may...

  6. 9 CFR 319.300 - Chili con carne.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food Products § 319.300 Chili con carne. “Chili con carne” shall contain not less than 40 percent of meat... 25 percent of the meat ingredients under specific declaration on the label. The mixture may...

  7. 9 CFR 319.300 - Chili con carne.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food Products § 319.300 Chili con carne. “Chili con carne” shall contain not less than 40 percent of meat... 25 percent of the meat ingredients under specific declaration on the label. The mixture may...

  8. 9 CFR 319.300 - Chili con carne.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food Products § 319.300 Chili con carne. “Chili con carne” shall contain not less than 40 percent of meat... 25 percent of the meat ingredients under specific declaration on the label. The mixture may...

  9. Breath Analysis Science at PittCon 2012, Orlando, Florida

    EPA Science Inventory

    Breath analysis science was featured in three organized sessions at this year’s Pittsburgh Conference and Exposition, or ‘PittCon 2012’ (http://www.pittcon.org/). As described in previous meeting reports, PittCon is one of the largest international conferences for analytical chem...

  10. Breath Analysis Science at PittCon 2012, Orlando, Florida

    EPA Science Inventory

    Breath analysis science was featured in three organized sessions at this year’s Pittsburgh Conference and Exposition, or ‘PittCon 2012’ (http://www.pittcon.org/). As described in previous meeting reports, PittCon is one of the largest international conferences for analytical chem...

  11. Combinación de radioterapia con quimioterapia mejora la supervivencia con raro cáncer cerebral

    Cancer.gov

    Los resultados de dos estudios clínicos de seguimiento a largo plazo confirman que ciertos pacientes viven substancialmente más si se les trata con una combinación de quimioterapia y radioterapia en comparación con radioterapia solamente.

  12. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Libro sobre el control del dolor en pacientes con cáncer. Cubre los métodos y medicinas, así como los efectos físicos y emocionales del dolor. Es una adaptación cultural para el público de habla hispana del libro en inglés Pain Control.

  13. Planificación Neuroquirúrgica con Software Osirix

    PubMed Central

    Jaimovich, Sebastián Gastón; Guevara, Martin; Pampin, Sergio; Jaimovich, Roberto; Gardella, Javier Luis

    2014-01-01

    Introducción: La individualidad anatómica es clave para reducir el trauma quirúrgico y obtener un mejor resultado. Actualmente, el avance en las neuroimágenes ha permitido objetivar esa individualidad anatómica, permitiendo planificar la intervención quirúrgica. Con este objetivo, presentamos nuestra experiencia con el software Osirix. Descripción de la técnica: Se presentan 3 casos ejemplificadores de 40 realizados. Caso 1: Paciente con meningioma de la convexidad parasagital izquierda en área premotora; Caso 2: Paciente con macroadenoma hipofisario, operada previamente por vía transeptoesfenoidal en otra institución con una resección parcial; Caso 3: Paciente con lesiones en pedúnculo cerebeloso medio bilateral. Se realizó la planificación prequirúrgica con el software OsiriX, fusionando y reconstruyendo en 3D las imágenes de TC e IRM, para analizar relaciones anatómicas, medir distancias, coordenadas y trayectorias, entre otras funciones. Discusión: El software OsiriX de acceso libre y gratuito permite al cirujano, mediante la fusión y reconstrucción en 3D de imágenes, analizar la anatomía individual del paciente y planificar de forma rápida, simple, segura y económica cirugías de alta complejidad. En el Caso 1 se pudo analizar las relaciones del tumor con las estructuras adyacentes para minimizar el abordaje. En el Caso 2 permitió comprender la anatomía post-operatoria previa del paciente, para determinar la trayectoria del abordaje transnasal endoscópico y la necesidad de ampliar su exposición, logrando la resección tumoral completa. En el Caso 3 permitió obtener las coordenadas estereotáxicas y trayectoria de una lesión sin representación tomográfica. Conclusión: En casos de no contar con costosos sistemas de neuronavegación o estereotáxia el software OsiriX es una alternativa a la hora de planificar la cirugía, con el objetivo de disminuir el trauma y la morbilidad operatoria. PMID:25165617

  14. Teaching after Retirement: The Pros and the Cons

    ERIC Educational Resources Information Center

    Sommer, Robert

    2014-01-01

    Having enjoyed teaching during my active career, I continued to teach summer school following retirement. Self-observed sensory and cognitive impairments, although not mentioned by students in their evaluations, induced me to consider the pros and cons of continuing to teach. My hope is that this list of benefits and problems will be of assistance…

  15. Detail of conning tower atop the submarine. Note the wire ...

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

    Detail of conning tower atop the submarine. Note the wire rope wrapped around the base of the tower, which may have been used in an attempt to pull the submarine offshore. - Sub Marine Explorer, Located along the beach of Isla San Telmo, Pearl Islands, Isla San Telmo, Former Panama Canal Zone, CZ

  16. Providers debate pros and cons of pneumonia vaccination at discharge.

    PubMed

    2001-02-01

    When to vaccinate against pneumonia? Does it makes sense when patients are in the hospital? Or should patients wait for the first post-op visit with the PCP? Office-based and hospital-based physicians weigh the pros and cons of each. PMID:11246808

  17. Teaching after Retirement: The Pros and the Cons

    ERIC Educational Resources Information Center

    Sommer, Robert

    2014-01-01

    Having enjoyed teaching during my active career, I continued to teach summer school following retirement. Self-observed sensory and cognitive impairments, although not mentioned by students in their evaluations, induced me to consider the pros and cons of continuing to teach. My hope is that this list of benefits and problems will be of assistance…

  18. LunGradCon: The Lunar Graduate Conference

    NASA Astrophysics Data System (ADS)

    Dove, A.; Poppe, A.; Neish, C.; Fagan, A.; Fuqua, H.; Kramer, G. Y.; Horanyi, M.

    2011-12-01

    Members of the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) initiated the Lunar Graduate Conference (LunGradCon), modeled after the highly successful Astrobiology Graduate Conference (AbGradCon). The purpose of this conference is to enhance the professional development of graduate students and early postdoctoral researchers by providing an opportunity to present and discuss scientific research in an environment of their peers. For the first two years, LunGradCon has been held as a one-day conference in conjunction with the NASA Lunar Science Institue's (NLSI) Lunar Science Forum at the NASA Ames Research Center. Activities include an invited overview talk on each of the NASA Lunar Science Institute's three main research areas (OF the Moon, ON the Moon, and FROM the Moon), submitted oral presentations from graduate students and postdoctoral researchers, and networking opportunities with established member of the lunar science community and the NLSI. In each of the first two years of LunGradCon, there have been 20-25 attendees, with about 15 of those presenting submitted talks. Each speaker received feedback forms from the other participants in order to improve on their presentation techniques. Participants also provided feedback on the conference as a whole in order to evaluate the content and provide suggestions for improvement in following years. Overall, the feedback has been extremely positive. This talk will summarize the achievements of past LunGradCons and plans for expansion of the conference to ensure a long-term positive impact on the early careers of future lunar, planetary and space science researchers.

  19. ConStrains identifies microbial strains in metagenomic datasets.

    PubMed

    Luo, Chengwei; Knight, Rob; Siljander, Heli; Knip, Mikael; Xavier, Ramnik J; Gevers, Dirk

    2015-10-01

    An important fraction of microbial diversity is harbored in strain individuality, so identification of conspecific bacterial strains is imperative for improved understanding of microbial community functions. Limitations in bioinformatics and sequencing technologies have to date precluded strain identification owing to difficulties in phasing short reads to faithfully recover the original strain-level genotypes, which have highly similar sequences. We present ConStrains, an open-source algorithm that identifies conspecific strains from metagenomic sequence data and reconstructs the phylogeny of these strains in microbial communities. The algorithm uses single-nucleotide polymorphism (SNP) patterns in a set of universal genes to infer within-species structures that represent strains. Applying ConStrains to simulated and host-derived datasets provides insights into microbial community dynamics. PMID:26344404

  20. Orbit and spin resolved magnetic properties of size selected [ConRh]? and [ConAu]? nanoalloy clusters.

    PubMed

    Dieleman, Dennis; Tombers, Matthias; Peters, Lars; Meyer, Jennifer; Peredkov, Sergey; Jalink, Jeroen; Neeb, Matthias; Eberhardt, Wolfgang; Rasing, Theo; Niedner-Schatteburg, Gereon; Kirilyuk, Andrei

    2015-11-14

    Bi-metallic nanoalloys of mixed 3d-4d or 3d-5d elements are promising candidates for technological applications. The large magnetic moment of the 3d materials in combination with a high spin-orbit coupling of the 4d or 5d materials give rise to a material with a large magnetic moment and a strong magnetic anisotropy, making them ideally suitable in for example magnetic storage devices. Especially for clusters, which already have a higher magnetic moment compared to the bulk, these alloys can profit from the cooperative role of alloying and size reduction in order to obtain magnetically stable materials with a large magnetic moment. Here, the influence of doping of small cobalt clusters on the spin and orbital magnetic moment has been studied for the cations [Co(8-14)Au](+) and [Co(10-14)Rh](+). Compared to the undoped pure cobalt [Co(N)](+) clusters we find a significant increase in the spin moment for specific Co(N-1)Au(+) clusters and a very strong increase in the orbital moment for some Co(N-1)Rh(+) clusters, with more than doubling for Co12Rh(+). This result shows that substitutional doping of a 3d metal with even just one atom of a 4d or 5d metal can lead to dramatic changes in both spin and orbital moment, opening up the route to novel applications. PMID:26104269

  1. Aspectos relacionados con la sexualidad y la reproducción (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de los factores que podrían afectar el funcionamiento sexual de las personas con cáncer. Se discuten además temás sobre la fertilidad relacionados con el tratamiento del cáncer.

  2. Aspectos relacionados con la sexualidad y la reproducción (PDQ)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca de los factores que pueden afectar el funcionamiento sexual de las personas con cáncer. Se discuten además temas sobre la fecundidad relacionados con el tratamiento del cáncer.

  3. Puncture in the canine fossa: technique and pros and cons.

    PubMed

    Neves-Pinto, R M; Medrado, A C; da Silva, C A; Palis, W

    1982-03-01

    The authors describe in detail the technique they are employing for puncturing the canine fossa, for irrigation, sinuscopy and/or register of the antral pressures. Two trocars are introduced, one developed and the other modified by one of the authors (N.P.) A morbid entity named "glue-sinus" is commented. The pros and cons of the technique are discussed concluding that puncture in the canine fossa is a valid procedure and even more advantageous than the one in the nasal inferior meatus. PMID:7071468

  4. Apoyo a Estudios Geodinamicos con GPS en Guatemala

    NASA Astrophysics Data System (ADS)

    Robles, V. R.

    2013-05-01

    El Instituto Geografico Nacional de Guatemala implemento 17 estaciones GNSS en el año 2009, como un proyecto de credito mixto de donacion de equipamiento del Gobierno de Suiza, el cual, este equipamiento de estaciones CORS GNSS es un sistema de recepción y transmisión de datos crudos GPS RInex que utiliza la tecnologia Spider Web de Leica, asi mismo este sistema esta sirviendo para el espablecimiento de un marco geodesico nacional de coordenadas geodesicas oficiales, el cual se calculan u obtienen las velocidades en tiempos temporales programados de las 17 Estaciones CORS. La infraestructura del marco geodesico de Guatemala esta sirviendo de base para las aplicaciones de estudios geodinamicos como el monitoreo de del desplazamiento de las placas tectonicas por medio de un estudio que se inicio en el año de 1999, llamado medicion con GPS el sistema de Fallas de los rios Polochic Motagua de Guatemala, tambien para un estudio que se implemento para deformación de corteza terrestre local en un Volcan Activo de Guatemala llamado Pacaya. Para el estudio de medicion con GPS en el sistema de falla de los Rios del polochic Motagua se implementaron 16 puntos para medir con GPS de dos frecuencias en el año de 1999, el cual, tres puntos son estaciones geodesicas CORS IGS llamados GUAT, ELEN y HUEH, despues en el año de 2003 se hizo otra medicion en un total de 20 puntos, que permitió calcular las velocidades de desplazamieinto de los puntos en mención, usando como referencia el modelo NUVEL 1A de DeMets de la placa de Norteamerica. Este estudio fue en cooperación internacional por la universidad de Nice de Francia y el IGNde Francia. Para el estudio del monitoreo con GPS del volcan activo de Guatemala, se implementaron cuatro puntos al rededor del volcan, el cual, se realizan cuatro mediciones al año, que permiten determinar axialmente la distancias entre los puntos, y rebisar estadisticamente cual es el comportamiento de las distancias en funcion del tiempo, si existen diferencias graduales crecientes o decrecientes, que nos da un indicativo del desplazamiento de la corteza terrestre al rededor del volcan.

  5. Checking the Pulse of PitCon '88.

    PubMed

    1988-03-18

    At PitCon '88-otherwise known as the Pittsburgh Conference and Exposition on Analytical Chemistry and Applied Spectroscopy-exhibited instruments capitalized on improvements in existing technology rather than novel concepts or design. This year's models feature increasing automation, particularly for aspects of sample presentation. The 1988 generation of so-called hyphenated systems emphasize a combination of techniques within the same work station-gas chromatography to detect and separate organic contaminants combined with mass spectrometry to identify them, for example. And in keeping with strict environmental standards, many companies are stressing the ability of their latest instruments to detect levels of environmental pollutants in the parts per billion, rather than parts per million, range. PitCon '88 lured more than 25,000 participants to New Orleans for the week of 22 to 26 February. Approximately 830 companies displayed their wares at 2400 booths, and it took two separate facilities to house them. Specialized symposia on advances in spectroscopic, chromatographic, and electrochemical techniques increased in number as did the number of individual talks and posters. And new this year were three general interest symposia-identifying antiques by spectrochemical techniques, cholesterol, and drug testing in the workplace. PMID:17769734

  6. [Modern tribology in total hip arthroplasty: pros and cons].

    PubMed

    Gómez-García, F

    2014-01-01

    The wear products and adverse reactions that occur on bearing surfaces represent one of the greatest challenges in prosthetic replacements, as the latter experience increasing demands due to the large number of young and older adult patients that have a long life expectancy and remarkable activity. The purpose of this review is to analyze the pros and cons of the new advances in the bearing components of the articular surfaces of current total hip arthroplasties. We also discuss the strategies used historically, their problems, results and the surgeon's role in prescribing the tribologic couple that best fits each patient's needs. We conclude with practical recommendations for the prescription and management of the latest articular couples for total hip arthroplasty. PMID:26021098

  7. Obtención de perfiles teóricos de elementos metálicos con velocidades macroscópicas

    NASA Astrophysics Data System (ADS)

    Cirigliano, D.; Costa, A.; Rovira, M.

    El propósito de este trabajo es poder establecer -a partir de la modelización de perfiles de distintas especies- patrones de comparación observacional que permitan caracterizar los fenómenos físicos que están presentes en las estructuras que se observan. Para ello se resuelven las ecuaciones de equilibrio de ionización para un determinado átomo y una atmósfera de parámetros determinados. A partir de ello se definen las poblaciones para los distintos grados de ionización. Considerando distintas configuraciones e intensidades de flujos de masa se deducen la función fuente, el espesor óptico y se calculan los perfiles de las distintas líneas. Se obtuvieron perfiles teóricos de líneas del CII, CIV y del OIV para flujos entrante, saliente y pasante. La forma del perfil, las intensidades relativas entre los distintos flujos y el corrimiento Doppler da cuenta de una caracterización teórica a partir de la cual se comparará con observaciones.

  8. RoboCon: Operator interface for robotic applications

    SciTech Connect

    Schempf, H.; Warwick, J.; Fung, M.; Chemel, B.; Blackwell, M.

    1996-12-31

    Carnegie Mellon U. and ORNL`s Robotics and Process Systems Division are developing a state-of-the-art robot operator control station (RoboCon) with standardized hardware and software control interfaces to be adaptable to a variety of remote and robotic equipment currently funded by DOE`s Office of Science & Technology Robotics Technology Development Program. The human operation and telerobotic and supervisory control of sophisticated and remote and robotic systems is a complex, tiring, and non-intuitive activity. Since decontamination & decommissioning, selective equipment removal, mixed waste operations, and in-tank cleanup are going to be a major future activity in DOE environmental restoration and waste management cleanup agenda, it seems necessary to utilize an operator control station and interface which maximizes operator comfort and productivity.

  9. Endoscopic scoring systems for inflammatory bowel disease: pros and cons.

    PubMed

    Tontini, Gian Eugenio; Bisschops, Raf; Neumann, Helmut

    2014-07-01

    Endoscopy plays a pivotal role for diagnosis and assessment of disease activity and extent in patients with inflammatory bowel diseases. International guidelines recommend the use of endoscopic scoring systems for evaluation of the prognosis and efficacy of medical treatments. Ideal scoring systems are easy to use, reproducible, reliable, responsive to changes, and validated in different clinical settings in order to guide therapeutic strategies. However, currently available endoscopic scoring systems often appear as complex for routine endoscopy and suffer from insufficient interobserver agreement and lack of formal validation which often limit their use in clinical trials. Here, we describe the role of endoscopic scoring systems in inflammatory bowel diseases focusing on pros and cons in the era of advanced endoscopic imaging and mucosal healing. PMID:24650249

  10. Neogene sequence stratigraphy, Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    McMillen, K.J.; Do Van Luu; Lee, E.K.; Hong, S.S.

    1996-12-31

    An integrated well log, biostratigraphic, and seismic stratigraphic study of Miocene to Recent deltaic sediments deposited in the Nam Con Son Basin offshore from southern Vietnam shows the influence of eustacy and tectonics on sequence development. Sediments consist of Oligocene non-marine rift-basin fill (Cau Formation), early to middle Miocene tide-dominated delta plain to delta front sediments (TB 1.5 to TB 2.5, Due and Thong Formations), and late Miocene to Recent marine shelf sediments (TB. 2.6 to TB 3.1 0, Mang Cau, Nam Con Son, and Bien Dong Formations). Eustacy controlled the timing of key surfaces and sand distribution in the tectonically-quiet early Miocene. Tectonic effects on middle to late Miocene sequence development consist of thick transgressive systems tracts due to basin-wide subsidence and transgression, sand distribution in the basin center, and carbonate sedimentation on isolated fault blocks within the basin. Third-order sequence boundaries (SB) are identified by spore peaks, sand stacking patterns, and channel incision. In the basin center, widespread shale beds with coal occur above sequence boundaries followed by transgressive sandstone units. These TST sandstones merge toward the basin margin where they lie on older HST sandstones. Maximum flooding surfaces (MFS) have abundant marine microfossils and mangrove pollen, a change in sand stacking pattern, and often a strong seismic reflection with downlap. Fourth-order genetic-type sequences are also interpreted. The MFS is the easiest marker to identify and correlate on well logs. Fourth-order SB occur within these genetic units but are harder to identify and correlate.

  11. Neogene sequence stratigraphy, Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    McMillen, K.J. ); Do Van Luu; Lee, E.K.; Hong, S.S. )

    1996-01-01

    An integrated well log, biostratigraphic, and seismic stratigraphic study of Miocene to Recent deltaic sediments deposited in the Nam Con Son Basin offshore from southern Vietnam shows the influence of eustacy and tectonics on sequence development. Sediments consist of Oligocene non-marine rift-basin fill (Cau Formation), early to middle Miocene tide-dominated delta plain to delta front sediments (TB 1.5 to TB 2.5, Due and Thong Formations), and late Miocene to Recent marine shelf sediments (TB. 2.6 to TB 3.1 0, Mang Cau, Nam Con Son, and Bien Dong Formations). Eustacy controlled the timing of key surfaces and sand distribution in the tectonically-quiet early Miocene. Tectonic effects on middle to late Miocene sequence development consist of thick transgressive systems tracts due to basin-wide subsidence and transgression, sand distribution in the basin center, and carbonate sedimentation on isolated fault blocks within the basin. Third-order sequence boundaries (SB) are identified by spore peaks, sand stacking patterns, and channel incision. In the basin center, widespread shale beds with coal occur above sequence boundaries followed by transgressive sandstone units. These TST sandstones merge toward the basin margin where they lie on older HST sandstones. Maximum flooding surfaces (MFS) have abundant marine microfossils and mangrove pollen, a change in sand stacking pattern, and often a strong seismic reflection with downlap. Fourth-order genetic-type sequences are also interpreted. The MFS is the easiest marker to identify and correlate on well logs. Fourth-order SB occur within these genetic units but are harder to identify and correlate.

  12. Performance of the RespiCon personal aerosol sampler in forest products industry workplaces.

    PubMed

    Tatum, Vickie; Ray, Alison E; Rovell-Rixx, David

    2002-01-01

    The RespiCon is a multistage virtual impactor that can be used as either a personal or an area sampler. Particles collected on the first stage of the RespiCon represent the respirable fraction of airborne particulate matter. Particles collected on the first and second stages represent the thoracic fraction, and particles collected on the first, second, and third stages represent the inhalable fraction. The RespiCon is available in two versions, one with photometric aerosol detection and a gravimetric version. In this study, the performance of the gravimetric version was examined in various forest products industry facilities. The precision of the RespiCon was assessed and its performance was compared with that of both a respirable cyclone and an inhalable dust sampler. In addition, some RespiCon samples were examined using scanning electron microscopy to determine physical particle size distribution. Under the conditions of this testing, the RespiCon appeared to be reasonably precise. For most sampling locations there was a close correspondence between measurements made with the RespiCon and the CIS personal inhalable sampler or the BGI-4 respirable cyclone. The results of microscopic examination of filters from the RespiCon were consistent with expected performance characteristics. The RespiCon is a useful sampling device for those situations in which it is important to simultaneously collect either personal or area samples of the respirable, thoracic, and inhalable fractions of airborne particulate matter. PMID:12173181

  13. Opciones de cirugía para mujeres con CDIS o con cáncer de seno- página de publicaciones

    Cancer.gov

    Contiene información sobre los tipos de cirugía de seno, como la operación para conservar el seno y la mastectomía, y ayuda a las mujeres diagnosticadas con CDIS o con cáncer de seno a decidir cuál cirugía es la más conveniente para ellas.

  14. Pros, Cons, and Alternatives to Weight Based Cost Estimating

    NASA Technical Reports Server (NTRS)

    Joyner, Claude R.; Lauriem, Jonathan R.; Levack, Daniel H.; Zapata, Edgar

    2011-01-01

    Many cost estimating tools use weight as a major parameter in projecting the cost. This is often combined with modifying factors such as complexity, technical maturity of design, environment of operation, etc. to increase the fidelity of the estimate. For a set of conceptual designs, all meeting the same requirements, increased weight can be a major driver in increased cost. However, once a design is fixed, increased weight generally decreases cost, while decreased weight generally increases cost - and the relationship is not linear. Alternative approaches to estimating cost without using weight (except perhaps for materials costs) have been attempted to try to produce a tool usable throughout the design process - from concept studies through development. This paper will address the pros and cons of using weight based models for cost estimating, using liquid rocket engines as the example. It will then examine approaches that minimize the impct of weight based cost estimating. The Rocket Engine- Cost Model (RECM) is an attribute based model developed internally by Pratt & Whitney Rocketdyne for NASA. RECM will be presented primarily to show a successful method to use design and programmatic parameters instead of weight to estimate both design and development costs and production costs. An operations model developed by KSC, the Launch and Landing Effects Ground Operations model (LLEGO), will also be discussed.

  15. Increasing the dietary intake of folate: pros and cons.

    PubMed

    Rothenberg, S P

    1999-01-01

    Studies providing unambiguous evidence that the occurrence and recurrence of pregnancies complicated by neural tube malformations were reduced by folic acid supplementation at the time of conception have prompted the Food and Drug Administration (FDA) to approve the fortification of cereal-grain products with this vitamin. Additional enthusiasm for this decision has emanated from studies that show an association of hyperhomocysteinemia with vascular disease and neural tube defects. Despite the apparent logic for the folic acid food fortification program, there are some concerns about the danger of such a policy to segments of the public who have unrecognized vitamin B12 deficiency because folate can mask the hematologic abnormalities and allow the neurological complications to progress or even accelerate. Thus, the apparent benefits of the folic acid fortification and the potential dangers of such a program have polarized opinions in favor of (pro) and in opposition to (con) this FDA policy. The purpose of this review is to present the evidence on which each of these two groups base their opinions. PMID:9930569

  16. Percutaneous coronary intervention in nonagenarians: pros and cons

    PubMed Central

    Biondi Zoccai, Giuseppe; Abbate, Antonio; D'Ascenzo, Fabrizio; Presutti, Davide; Peruzzi, Mariangela; Cavarretta, Elena; Marullo, Antonino G.M.; Lotrionte, Marzia; Frati, Giacomo

    2013-01-01

    Percutaneous coronary intervention is a mainstay in the management of symptomatic or high-risk coronary artery disease. The bulk of clinical evidence and experience underlying this fact relies, however, on relatively young patients. Indeed, few data of very limited quality are available which adequately define the risk-benefit and cost-benefit profile of coronary angioplasty and stenting in very old subjects, such as those of 90 years of age or older (i.e., nonagenarians). The aim of this review is to provide a concise, yet practical, synthesis of the available evidence on percutaneous coronary revascularization in the very elderly. The main arguments elaborated upon are to what extent we can extrapolate findings from studies including younger patients to nonagenarians, whether we should provide higher priority to prognosis or quality of life in such patients, and whether we can afford to allocate vast resources to care for such subjects in an era of financial constraints. Our review of 18 studies and 1082 patients suggest that percutaneous coronary intervention is feasible and associated with acceptable short- and long-term results in this population, which is nonetheless fraught with a high mortality risk irrespective of the revascularization procedure. Accordingly, the pros and cons of percutaneous coronary intervention should be carefully weighed when considering this treatment in nonagenarians. PMID:23610578

  17. Perfiles de luminosidad en galaxias con núcleo tipo Seyfert 1

    NASA Astrophysics Data System (ADS)

    Boris, N.; Rodriguez-Ardilla, A. A.; Pastoriza, M. G.

    Presentamos imágenes CCD en los filtros BVI y H? de una muestra de 10 galaxias Seyfert 1 y Narrow Line Seyfert 1. Recientes observaciones muestran que hay una diferencia significante en el índice espectral óptico entre NLS1s y Sy1 normales, siendo para las primeras del orden de 2. Otra característica importante es que la mayor parte de las NLS1s muestran tasas de FeII/H? mayores que las observadas en otras Sy1s. Desde el punto de vista fotométrico, estas galaxias no tienenningún tipo de estudio previo. Presentamos magnitudes totales, perfiles de luminosidad y mapas de color junto con un detallado análisis de la formación estelar en estos objetos. Encontramos que la descomposición en bulbo + disco representa adecuadamente los perfiles de luminosidad de las galaxias de la muestra. Sin embargo, en todos los casos es necesario que el disco tenga un agujero en su centro. El radio de este agujero va desde los 3 a los 9 kpc. Si bien no tenemos aún una explicación para este hecho, los agujeros parecen estar asociados a anillos circumnucleares de alto oscurecimiento E(B-V) ~1. Los perfiles presentan también un fuerte gradiente de color, siendo notablemente más azules hacia la región nuclear. Los objetos de la muestra cubren todo el rango de tipos morfológicos, no obstante, no encontramos regiones de formación estelar en las regiones exteriores de las galaxias. La formación estelar está confinada a la región nuclear y se data en alrededor de 5 x 107 años.

  18. Investigation on the conA binding properties of Klebsiella pneumoniae.

    PubMed

    Anuar, A S S; Tay, S T

    2014-12-01

    Klebsiella pneumoniae is a healthcare-associated bacterial pathogen which causes severe diseases in immunocompromised individuals. Concanavalin A (conA), a lectin which recognizes proteins with mannose or glucose residues, has been reported to agglutinate K. pneumoniae and hence, is postulated to have therapeutical potential for K. pneumoniae-induced liver infection. This study investigated the conA binding properties of a large collection of clinical isolates of K. pneumoniae. ConA agglutination reaction was demonstrated by 94 (51.4%) of 183 K. pneumoniae isolates using a microtiter plate assay. The conA agglutination reactions were inhibited in the presence of 2.5 mg/ml D-mannose and 2.5 mg/ml glucose, and following pretreatment of the bacterial suspension with protease and heating at 80ºC. Majority of the positive isolates originated from respiratory specimens. Isolation of conA-binding proteins from K. pneumoniae ATCC 700603 strain was performed using conA affinity column and the conA binding property of the eluted proteins was confirmed by western blotting analysis using conA-HRP conjugates. Proteins with molecular weights ranging from 35 to 60 kDa were eluted from the conA affinity column, of which four were identified as outer membrane protein precursor A (37 kDa), outer membrane protein precursor C (40 kDa), enolase (45 kDa) and chaperonin (60 kDa) using mass spectrometry analysis. Several conA binding proteins (including 45 and 60 kDa) were found to be immunogenic when reacted with rabbit anti-Klebsiella antibody. The function and interplay of the conA binding proteins in bacterium-host cell relationship merits further investigation. PMID:25776607

  19. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Contiene información sobre las medicinas contra el dolor para pacientes con cáncer, los planes para controlarlo, cómo hablar con su equipo de atención médica sobre el dolor que usted siente y qué hacer para controlar los efectos físicos y emocionales del

  20. Pruebas de BRCA en pacientes jóvenes con cáncer

    Cancer.gov

    Pruebas de mutaciones genéticas fuertemente asociadas con un mayor riesgo de cáncer de seno han aumentado dramáticamente entre mujeres menores de 40 años diagnosticadas con la enfermedad, según un nuevo estudio.

  1. ConSearch: An Electronic Document Research and Retrieval Utility for Windows from Management Information Technologies.

    ERIC Educational Resources Information Center

    Combs, Joseph, Jr.

    1995-01-01

    Reviews ConSearch 3.0, a product that provides flexible searching of electronic files, allowing the location of related meanings as well as exact matches. ConSearch 3.0 differs from other file retrieval approaches by relating words in search phrases of questions to the "meaning" of the words, which are stored in a "conceptual database," or lexicon…

  2. Gestational surrogacy: could be a way to be a way to reproduction? Pros and cons.

    PubMed

    Clementina, Peris

    2011-06-01

    The aim of this article was to address pros and cons of gestational surrogacy, the social and psychological issues involved in surrogate motherhood triads. Pros and cons of surrogacy, the possible insurgence of a hematologic disease in the fetus, hemolytic disease of the newborn, naturally acquired microchimerism in surrogacy cases, ethical, medical, psychologic, legal and religious issues of a problem are discussed. PMID:21778533

  3. Meeting Report: Breath Biomarkers Networking Sessions at PittCon 2010, Orlando, Florida

    EPA Science Inventory

    The Pittsburgh Conference and Exposition, or "PittCon" (www.pittcon.org/), is one of the largest international conferences for analytical chemistry and instrumentation typically attracting about 25,000 attendees and 1,000 commercial exhibitors. PittCon began in 1950 as a small sp...

  4. Synergistic hemolysins of coagulase-negative staphylococci (CoNS).

    PubMed

    Ró?alska, Ma?gorzata; Derczy?ska, Anna; Maszewska, Agnieszka

    2015-01-01

    A total of 104 coagulase negative staphylococci, belonging to S. capitis, S. hominis, S. haemolyticus and S. warneri, originating from the collection of the Department of Pharmaceutical Microbiology (ZMF), Medical University of Lodz, Poland, were tested for their synergistic hemolytic activity. 83% of strains produced ?-hemolysin, however, the percentage of positive strains of S. haemolyticus, S. warneri, S. capitis and S. hominis was different - 98%, 78%, 75% and 68%, respectively. Highly pure hemolysins were obtained from culture supernatants by protein precipitation with ammonium sulphate (0-70% of saturation) and extraction by using a mixture of organic solvents. The purity and molecular mass of hemolysins was determined by TRIS/Tricine PAGE. All CoNS hemolysins were small peptides with a molar mass of about 3.5 kDa; they possessed cytotoxic activity against the line of human foreskin fibroblasts ATCC Hs27 and lysed red cells from different mammalian species, however, the highest activity was observed when guinea pig, dog and human red blood cells were used. The cytotoxic effect on fibroblasts occurred within 30 minutes. The S. cohnii ssp. urealyticus strain was used as a control. The antimicrobial activity was examined using hemolysins of S. capitis, S. hominis, S. cohnii ssp. cohnii and S. cohnii ssp. urealyticus. Hemolysins of the two S. cohnii subspecies did not demonstrate antimicrobial activity. Cytolysins of S. capitis and S. hominis had a very narrow spectrum of action; out of 37 examined strains, the growth of only Micrococcus luteus, Corynebacterium diphtheriae and Pasteurella multocida was inhibited. PMID:26634231

  5. Self-Exfoliated Guanidinium-Based Ionic Covalent Organic Nanosheets (iCONs).

    PubMed

    Mitra, Shouvik; Kandambeth, Sharath; Biswal, Bishnu P; Khayum M, Abdul; Choudhury, Chandan K; Mehta, Mihir; Kaur, Gagandeep; Banerjee, Subhrashis; Prabhune, Asmita; Verma, Sandeep; Roy, Sudip; Kharul, Ulhas K; Banerjee, Rahul

    2016-03-01

    Covalent organic nanosheets (CONs) have emerged as functional two-dimensional materials for versatile applications. Although ?-? stacking between layers, hydrolytic instability, possible restacking prevents their exfoliation on to few thin layered CONs from crystalline porous polymers. We anticipated rational designing of a structure by intrinsic ionic linker could be the solution to produce self-exfoliated CONs without external stimuli. In an attempt to address this issue, we have synthesized three self-exfoliated guanidinium halide based ionic covalent organic nanosheets (iCONs) with antimicrobial property. Self-exfoliation phenomenon has been supported by molecular dynamics (MD) simulation as well. Intrinsic ionic guanidinium unit plays the pivotal role for both self-exfoliation and antibacterial property against both Gram-positive and Gram-negative bacteria. Using such iCONs, we have devised a mixed matrix membrane which could be useful for antimicrobial coatings with plausible medical benefits. PMID:26866697

  6. The International Consortium for the Investigation of Renal Malignancies (I-ConFIRM)

    Cancer.gov

    The International Consortium for the Investigation of Renal Malignancies (I-ConFIRM) was formed to promote international, multidisciplinary collaborations to advance our understanding of the etiology and outcomes of kidney cancer.

  7. SLUDGE PARTICLE SEPAPATION EFFICIENCIES DURING SETTLER TANK RETRIEVAL INTO SCS-CON-230

    SciTech Connect

    DEARING JI; EPSTEIN M; PLYS MG

    2009-07-16

    The purpose of this document is to release, into the Hanford Document Control System, FA1/0991, Sludge Particle Separation Efficiencies for the Rectangular SCS-CON-230 Container, by M. Epstein and M. G. Plys, Fauske & Associates, LLC, June 2009. The Sludge Treatment Project (STP) will retrieve sludge from the 105-K West Integrated Water Treatment System (IWTS) Settler Tanks and transfer it to container SCS-CON-230 using the Settler Tank Retrieval System (STRS). The sludge will enter the container through two distributors. The container will have a filtration system that is designed to minimize the overflow of sludge fines from the container to the basin. FAI/09-91 was performed to quantify the effect of the STRS on sludge distribution inside of and overflow out of SCS-CON-230. Selected results of the analysis and a system description are discussed. The principal result of the analysis is that the STRS filtration system reduces the overflow of sludge from SCS-CON-230 to the basin by roughly a factor of 10. Some turbidity can be expected in the center bay where the container is located. The exact amount of overflow and subsequent turbidity is dependent on the density of the sludge (which will vary with location in the Settler Tanks) and the thermal gradient between the SCS-CON-230 and the basin. Attachment A presents the full analytical results. These results are applicable specifically to SCS-CON-230 and the STRS filtration system's expected operating duty cycles.

  8. Evaluation of the ACT*DE*CON{sup SM} process for treating gunite tank sludge

    SciTech Connect

    Spencer, B.B.; Chase, C.W.; Egan, B.Z.

    1996-05-01

    A test was conducted to evaluate this process for selectively removing actinides from Gunite tank sludge. Mixed waste sludge from Gunite tank W-6 was subjected to the ACT*DE*CON selective leaching process. (Nearly all the TRU content was attributed to Pu.) The sludge sample was first washed with 0.01M NaOH to remove excess sodium and nitrate in the interstitial liquid supernatant. The washed wet solids were treated with the ACT*DE*CON solvent (aqueous carbonate solution containing a chelating agent and an oxidant), using a ratio of 20 ml solvent per gram wet solids. Sludge and solvent were separated by centrifugation, and the ACT*DE*CON treatment was repeated twice. Analyses showed that 71% of the solids in the sludge were dissolved while 80% of the TRU-waste components dissolved. Low separation of the TRU-waste components from other components of the sludge mixture is indicated. Almost all the U and Ca were removed from the sludge. For sludges where most of the TRU content is Pu, the ACT*DE*CON process as tested is not effective in rendering the sludge a non-TRU waste. It is recommended that ACT*DE*CON be optimized for this specific application and that other processes using different chelating and oxidizing agents be tested. Also, the ACT*DE*CON process should be tested on TRU mixed waste in which most of the TRU elements are not Pu.

  9. Concomitant administration of GonaCon™ and rabies vaccine in female dogs (Canis familiaris) in Mexico.

    PubMed

    Vargas-Pino, Fernando; Gutiérrez-Cedillo, Verónica; Canales-Vargas, Erick J; Gress-Ortega, Luis R; Miller, Lowell A; Rupprecht, Charles E; Bender, Scott C; García-Reyna, Patricia; Ocampo-López, Juan; Slate, Dennis

    2013-09-13

    Mexico serves as a global model for advances in rabies prevention and control in dogs. The Mexican Ministry of Health (MMH) annual application of approximately 16 million doses of parenteral rabies vaccine has resulted in significant reductions in canine rabies during the past 20 years. One collateral parameter of rabies programs is dog population management. Enhanced public awareness is critical to reinforce responsible pet ownership. Surgical spaying and neutering remain important to prevent reproduction, but are impractical for achieving dog population management goals. GonaCon™, an anti-gonadotropin releasing hormone (GnRH) vaccine, was initially tested in captive female dogs on the Navajo Nation, 2008. The MMH led this international collaborative study on an improved formulation of GonaCon™ in captive dogs with local representatives in Hidalgo, Mexico in 2011. This study contained 20 bitches assigned to Group A (6 control), Group B (7 GonaCon™), and Group C (7 GonaCon™ and rabies vaccine). Vaccines were delivered IM. Animals were placed under observation and evaluated during the 61-day trial. Clinically, all dogs behaved normally. No limping or prostration was observed, in spite of minor muscle atrophy post-mortem in the left hind leg of dogs that received GonaCon™. Two dogs that began the study pregnant give birth to healthy pups. Dogs that received a GonaCon™ injection had macro and microscopic lesions consistent with prior findings, but the adverse injection effects were less frequent and lower in intensity. Both vaccines were immunogenic based on significant increases in rabies virus neutralizing antibodies and anti-GnRH antibodies in treatment Groups B and C. Simultaneous administration of GonaCon™ and rabies vaccine in Group C did not affect immunogenicity. Progesterone was suppressed significantly in comparison to controls. Future studies that monitor fertility through multiple breeding cycles represent a research need to determine the value of integrating this vaccine into dog rabies management. PMID:23871822

  10. Con-specific neighbours may enhance compensation capacity in an invasive plant.

    PubMed

    Lu, X; Dai, H; Ding, J

    2010-05-01

    Facilitation, both by inter- and intra-specific neighbours, is known to be an important process in structuring plant communities. However, only a small number of experiments have been reported on facilitation in plant invasions, especially between invasive con-specific individuals. Here, we focus on how con-specific neighbours of the invasive alien plant alligator weed affect the tolerance of alligator weed to herbivory by the introduced biological control agent, Agasicles hygrophila. We conducted greenhouse and garden experiments in which invasive plant density and herbivory intensity (artificial clipping and real herbivory) were manipulated. In the greenhouse experiment, artificial clipping significantly reduced plant biomass when plants were grown individually, but when con-specific neighbours were present in the same pot, biomass was not significantly different from control plants. Similarly, when compared to control plants, plants that were subjected to herbivory by A. hygrophila produced more biomass when grown with two con-specific neighbours than when grown alone. Real herbivory also resulted in an increased number of vegetative buds, and again when two con-specific neighbours were present this effect was increased (a 55.3% increase in buds when there was no neighbour, but a 111.6% increase in buds when two con-specific neighbours were present). In the garden experiment, in which plants were grown at high density (6 plants per pot), alligator weed fully recovered from defoliation caused by insects at levels from 20-30% to 100%. Our results indicate that the con-specific association may increase the compensatory ability to cope with intense damage in this invasive plant. PMID:20522180

  11. ConA-based glucose sensing using the long-lifetime azadioxatriangulenium fluorophore

    NASA Astrophysics Data System (ADS)

    Cummins, Brian; Simpson, Jonathan; Gryczynski, Zygmunt; Sørensen, Thomas Just; Laursen, Bo W.; Graham, Duncan; Birch, David; Coté, Gerard

    2014-02-01

    Fluorescent glucose sensing technologies have been identified as possible alternatives to current continuous glucose monitoring approaches. We have recently introduced a new, smart fluorescent ligand to overcome the traditional problems of ConA-based glucose sensors. For this assay to be translated into a continuous glucose monitoring device where both components are free in solution, the molecular weight of the smart fluorescent ligand must be increased. We have identified ovalbumin as a naturally-occurring glycoprotein that could serve as the core-component of a 2nd generation smart fluorescent ligand. It has a single asparagine residue that is capable of displaying an N-linked glycan and a similar isoelectric point to ConA. Thus, binding between ConA and ovalbumin can potentially be monovalent and sugar specific. This work is the preliminary implementation of fluorescently-labeled ovalbumin in the ConA-based assay. We conjugate the red-emitting, long-lifetime azadioxatriangulenium (ADOTA+) dye to ovalbumin, as ADOTA have many advantageous properties to track the equilibrium binding of the assay. The ADOTA-labeled ovalbumin is paired with Alexa Fluor 647-labeled ConA to create a Förster Resonance Energy Transfer (FRET) assay that is glucose dependent. The assay responds across the physiologically relevant glucose range (0-500 mg/dL) with increasing intensity from the ADOTA-ovalbumin, showing that the strategy may allow for the translation of the smart fluorescent ligand concept into a continuous glucose monitoring device.

  12. Structural basis of ConM binding with resveratrol, an anti-inflammatory and antioxidant polyphenol.

    PubMed

    Rocha, Bruno A M; Teixeira, Claudener S; Silva-Filho, José C; Nóbrega, Raphael B; Alencar, Daniel B; Nascimento, Kyria S; Freire, Valder N; Gottfried, Carmem J S; Nagano, Celso S; Sampaio, Alexandre H; Saker-Sampaio, Silvana; Cavada, Benildo S; Delatorre, Plínio

    2015-01-01

    Resveratrol can also inhibit the activation of proinflammatory mediators and cytokines at the early gene expression stage. It is well known that lectins are sugar-binding proteins that act as both pro- and anti-inflammatory molecules. Thus, the objective of this work was to verify the binding of a polyphenol compound with a lectin of Canavalia maritima (ConM) based on their ability to inhibit pro-inflammatory processes. To accomplish this, ConM was purified and crystallized, and resveratrol was soaked at 5mM for 2h of incubation. The crystal belongs to the monoclinic space group C2, the final refinement resulted in an Rfactor of 16.0% and an Rfree of 25.5%. Resveratrol binds in the rigid ?-sheet through H-bonds and hydrophobic interaction with amino acids that compose the fifth and sixth ?-strands of the rigid ?-sheet of ConM. The ConM and resveratrol inhibited DPPH oxidation, showing synergic activity with the most effective ratio of 2:3 and carbohydrate binding site is not directly related to antioxidant activity. It is the interaction between ConM and resveratrol that indicates the synergism of these two molecules in acting as free radicals scavengers and in reducing the inflammatory process through the inhibition of many pro-inflammatory events. PMID:25192853

  13. C-ON Bond Homolysis of Alkoxyamines, Part 11: Activation of the Nitroxyl Fragment.

    PubMed

    Audran, Gérard; Brémond, Paul; Marque, Sylvain R A; Yamasaki, Toshihide

    2016-03-01

    A few years ago, Bagryanskaya and colleagues (J. Org. Chem. 2011) showed that protonation of the nitroxyl fragment deactivated the alkoxyamine C-ON bond. Conversely, our group showed that protonation (Chem. Commun. 2011), as well as other chemical reactions such as oxidation or amine quaternization (Org. Lett. 2012), of the pyridyl moiety carried by the alkyl fragment was suitable to activate the homolysis of the C-ON bond. To pursue our goal of applying alkoxyamines as theranostic agents (Org. Biomol. Chem. 2014 and Mol. Pharmaceutics 2014) by activation of the C-ON bond homolysis, we turned our interest to the chemical activation of the nitroxyl fragment by oxidation/reduction of selected functions. Conversion of a hydroxyl group located close to the nitroxyl moiety successively into aldehyde, then acid, and eventually into ester, led to a successive decrease in kd. PMID:26878593

  14. Nuevas observaciones de 3C10 con el VLA*: estudio de la expansión

    NASA Astrophysics Data System (ADS)

    Reynoso, E. M.; Moffett, D. A.:; Dubner, G. M.; Giacani, E. B.; Reynolds, S. P.; Goss, W. M.; Dickel, J.

    Se presentan nuevos resultados sobre la expansión del remanente de la supernova de Tycho a lo largo de un intervalo de 10.9 años, comparando nuevas observaciones tomadas con el VLA a 1375 y 1635 MHz durante 1994 y 1995, con observaciones previas realizadas entre 1983 y 1984 (Dickel y col. ~1991 AJ 101, 2151), usando las mismas configuraciones, anchos de banda, calibradores y tiempos de integración. El coeficiente de expansión se calcula para sectores radiales de 4o de ancho cada uno, ajustando la correlación cruzada de las derivadas de los perfiles promedio para cada época. A partir de la expansión medida, se estima el índice (parámetro de expansión) de la ley potencial R? tm como m? d ln R/d ln t . Este valor se compara con coeficientes teóricos para diferentes fases evolutivas de remanentes de supernova.

  15. [Le disfunzioni sessuali in pazienti con primo esordio psicotico valutati secondo una prospettiva di genere].

    PubMed

    Ciocca, Giacomo; Usall, Judith; Dolz, Montse; Limoncin, Erika; Gravina, Giovanni L; Carosa, Eleonora; Sánchez, Bernardo; Barajas, Ana; Baños, Iris; Huerta, Elena; Farreny, Aida; Franchi, Camilla; Group, Genipe; Ochoa, Susana

    2015-01-01

    RIASSUNTO. Scopo. I pazienti con un disturbo mentale cronico spesso possono soffrire di disfunzioni sessuali. La funzione sessuale dei nuovi pazienti con primo esordio psicotico è stata poco studiata. L'obiettivo di questo studio è quello di indagare le differenze di genere nella funzione sessuale in persone con primo episodio psicotico. Metodi. Hanno partecipato alla ricerca un gruppo di 40 uomini e 37 donne con primo episodio psicotico, a cui è stato somministrato un protocollo psichiatrico composto dalla PANSS, dall'UKU, e dalla SCID-DSM-IV per effettuare la diagnosi. Risultati. Nel gruppo maschile, il 42,5% dei pazienti aveva disfunzioni sessuali, mentre la percentuale nelle gruppo femminile è stata del 37,8%. Non c'è stata nessuna correlazione tra disfunzioni sessuali e psicopatologia negli uomini. Invece, nelle donne la psicopatologia generale e i sintomi positivi sono risultati associati all'alterazione della lubrificazione vaginale (r=0,547; p=0,003) and (r=0,485; p=0,011), sebbene anche l'alterazione nella risposta orgasmica è risultata correlare con la psicopatologia generale (r=0,500; p=0,013). Inoltre, è stata trovata un'associazione tra l'alterazione della lubrificazione vaginale con la depressione (r=0,627; p<0,0001) e il disturbo della volontà (r=0,600; p<0,001). Discussione e conclusioni. Questi dati suggeriscono che l'associazione tra disfunzioni sessuali e psicopatologia ha riguardato esclusivamente le donne. Pertanto, durante la presa in carico dei pazienti è fondamentale considerare l'associazione genere-specifica tra psicopatologia e problemi sessuali. PMID:26489073

  16. ConTour: Data-Driven Exploration of Multi-Relational Datasets for Drug Discovery

    PubMed Central

    Partl, Christian; Lex, Alexander; Streit, Marc; Strobelt, Hendrik; Wassermann, Anne-Mai; Pfister, Hanspeter; Schmalstieg, Dieter

    2016-01-01

    Large scale data analysis is nowadays a crucial part of drug discovery. Biologists and chemists need to quickly explore and evaluate potentially effective yet safe compounds based on many datasets that are in relationship with each other. However, there is a lack of tools that support them in these processes. To remedy this, we developed ConTour, an interactive visual analytics technique that enables the exploration of these complex, multi-relational datasets. At its core ConTour lists all items of each dataset in a column. Relationships between the columns are revealed through interaction: selecting one or multiple items in one column highlights and re-sorts the items in other columns. Filters based on relationships enable drilling down into the large data space. To identify interesting items in the first place, ConTour employs advanced sorting strategies, including strategies based on connectivity strength and uniqueness, as well as sorting based on item attributes. ConTour also introduces interactive nesting of columns, a powerful method to show the related items of a child column for each item in the parent column. Within the columns, ConTour shows rich attribute data about the items as well as information about the connection strengths to other datasets. Finally, ConTour provides a number of detail views, which can show items from multiple datasets and their associated data at the same time. We demonstrate the utility of our system in case studies conducted with a team of chemical biologists, who investigate the effects of chemical compounds on cells and need to understand the underlying mechanisms. PMID:26356902

  17. Asociación de XMRV con enfermedades humanas se debe a contaminación

    Cancer.gov

    Nuevas investigaciones muestran que una asociación, mencionada en numerosos estudios, entre el retrovirus conocido como XMRV y el cáncer de próstata así como el síndrome de fatiga crónica, se debe a contaminación de laboratorio con un virus que se originó en ratones.

  18. Algunas mujeres con cáncer de seno pueden abstenerse de quimioterapia

    Cancer.gov

    Resumen de resultados del estudio TAILORx indica que mujeres con cáncer de seno receptor de hormonas en estadio inicial tienen un riesgo bajo de recurrencia según una prueba de expresión de 21 genes.

  19. Non Invasive Biomedical Analysis - Breath Networking Session at PittCon 2011, Atlanta, Georgia

    EPA Science Inventory

    This was the second year that our breath colleagues organized a networking session at the Pittsburgh Conference and Exposition or ''PittCon'' (http://www.pincon.org/).This time it was called "Non-invasive Biomedical Analysis" to broaden the scope a bit, but the primary focus rema...

  20. CHILES Con Pol: An ultra-deep JVLA survey probing galaxy evolution and cosmic magnetism

    NASA Astrophysics Data System (ADS)

    Hales, Christopher A.; Momjian, Emmanuel; van Gorkom, Jacqueline; Rupen, Michael P.; Greiner, Maksim; Ensslin, Torsten A.; Bonzini, Margherita; Padovani, Paolo; Harrison, Ian; Brown, Michael L.; Gim, Hansung; Yun, Min S.; Maddox, Natasha; Stewart, Adam; Fender, Rob P.; Tremou, Evangelia; Chomiuk, Laura; Peters, Charee; Wilcots, Eric M.; Lazio, Joseph

    2015-08-01

    We are undertaking a 1000 hour campaign with the Karl G. Jansky VLA to survey 0.2 square degrees of the COSMOS field in full polarization continuum at 1.4 GHz. Our observations are part of a joint program with the spectral line COSMOS HI Large Extragalactic Survey (CHILES). When complete, we expect our CHILES Continuum Polarization (CHILES Con Pol) survey to reach an SKA-era sensitivity of 500 nJy per 4 arcsecond resolving beam, the deepest view of the radio sky yet. CHILES Con Pol will open new and fertile parameter space, with sensitivity to star formation rates of 10 Msun per year out to an unprecedented redshift of z=2, and ultra-luminous infrared galaxies and sub-millimeter galaxies out to redshifts of z=8 and beyond. This rich resource will extend the utility of radio band studies beyond the usual radio quasar and radio galaxy populations, opening sensitivity to the starforming and radio-quiet AGN populations that form the bulk of extragalactic sources detected in the optical, X-ray, and infrared bands. In this talk I will outline the key science of CHILES Con Pol, including galaxy evolution and novel measurements of intergalactic magnetic fields. I will present initial results from the first 180 hours of the survey and describe our forthcoming Data Release 1. I invite the astronomical community to consider unique science that can be pursued with CHILES Con Pol radio data.

  1. Jóvenes con cáncer y supervivientes participan en estudio de oncofertilidad

    Cancer.gov

    Artículo sobre los esfuerzos que se realizan para conectar con pacientes jóvenes y lograr su participación en estudios clínicos para evaluar y remediar la esterilidad causada por el cáncer y su tratamiento.

  2. A Manual for Merger. A Guide to Examine the Feasibility & Implications of Merger: The Pros & Cons.

    ERIC Educational Resources Information Center

    Bridgman, John N., Jr., Ed.

    Written for boards of education, school administrators, and others who wish to explore the possibilities of merger within their own counties, this manual examines the pros and cons through the experiences of those who have implemented school district mergers in recent years in North Carolina. Guidelines are provided for implementing mergers…

  3. Impact of the ConRed program on different cyberbulling roles.

    PubMed

    Del Rey, Rosario; Casas, José A; Ortega, Rosario

    2016-03-01

    This article presents results from an evaluation of the ConRed cyberbullying intervention program. The program's impacts were separately determined for the different roles within cyberbullying that students can take, i.e., cyber-victims, cyber-bullies, cyber-bully/victims, and bystanders. The ConRed program is a theory-driven program designed to prevent cyberbullying and improve cyberbullying coping skills. It involves students, teachers, and families. During a 3-month period, external experts conducted eight training sessions with students, two with teachers and one with families. ConRed was evaluated through a quasi-experimental design, in which students from three secondary schools were separated into experimental and control groups. The sample comprised 875 students, aged between 11 and 19 years. More students (n = 586) were allocated to the experimental groups at the specific insistence of the management of all schools; the remainder (n = 289) formed the control. Repeated measures MANOVA showed that cyber victims, cyber aggressors and cyberbully/victims reduced their involvement in cyberbullying. Moreover, cyber-victims and bystanders adjusted their perceptions about their control of personal information on the Internet, and cyber aggressors and bystanders reduced their Internet dependence. The ConRed program had stronger effects on male participants, especially in heightening their affective empathy. Aggr. Behav. 42:123-135, 2016. © 2015 Wiley Periodicals, Inc. PMID:26351131

  4. Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas

    NASA Astrophysics Data System (ADS)

    Landau, S. J.; Sisterna, P. D.; Vucetich, H.

    Se estudian las violaciones al Principio de Equivalencia en Teorías con Dilatón de Cuerdas. En estos modelos, algunas de las constantes fundamentales dependen del espacio y del tiempo. Se muestra que los experimentos de caída libre no tienen aún precisión como para poner límites a los parámetros de la teoría.

  5. 40 CFR 227.27 - Limiting permissible con-cen-tra-tion (LPC).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Limiting permissible con-cen-tra-tion (LPC). 227.27 Section 227.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Definitions § 227.27 Limiting...

  6. 40 CFR 227.27 - Limiting permissible con-cen-tra-tion (LPC).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Limiting permissible con-cen-tra-tion (LPC). 227.27 Section 227.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Definitions § 227.27 Limiting...

  7. 40 CFR 227.27 - Limiting permissible con-cen-tra-tion (LPC).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Limiting permissible con-cen-tra-tion (LPC). 227.27 Section 227.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Definitions § 227.27 Limiting...

  8. 40 CFR 227.27 - Limiting permissible con-cen-tra-tion (LPC).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Limiting permissible con-cen-tra-tion (LPC). 227.27 Section 227.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Definitions § 227.27 Limiting...

  9. Optimizing Electrospray Interfaces Using Slowly Diverging Conical Duct (ConDuct) Electrodes

    NASA Astrophysics Data System (ADS)

    Krutchinsky, Andrew N.; Padovan, Júlio C.; Cohen, Herbert; Chait, Brian T.

    2015-04-01

    We demonstrate that the efficiency of ion transmission from atmosphere to vacuum through stainless steel electrodes that contain slowly divergent conical duct (ConDuct) channels can be close to 100%. Here, we explore the properties of 2.5-cm-long electrodes with angles of divergence of 0°, 1°, 2°, 3°, 5°, 8°, 13°, and 21°, respectively. The ion transmission efficiency was observed to jump from 10-20% for the 0° (straight) channels to 90-95% for channels with an angle of divergence as small as 1°. Furthermore, the 2-3° ConDuct electrodes produced extraordinarily low divergence ion beams that propagated in a laser-like fashion over long distances in vacuum. To take advantage of these newly discovered properties, we constructed a novel atmosphere-to-vacuum ion interface utilizing a 2° ConDuct as an inlet electrode and compared its ion transmission efficiency with that of the interface used in the commercial (Thermo Fisher Scientific, San Jose, CA, USA) Velos Orbitrap and Q Exactive mass spectrometers. We observed that the ConDuct interface transmitted up to 17 times more ions than the commercial reference interface and also yielded improved signal-to-noise mass spectra of peptides. We infer from these results that the performance of many current atmosphere-to-vacuum interfaces utilizing metal capillaries can be substantially improved by replacing them with 1° or 2° metal ConDuct electrodes, which should preserve the convenience of supplying ion desolvation energy by heating the electrode while greatly increasing the efficiency of ion transmission into the mass spectrometer.

  10. ConMap - a new spatial data mining framework for terrain based digital soil mapping

    NASA Astrophysics Data System (ADS)

    Behrens, T.; Schmidt, K.; Scholten, T.

    2009-04-01

    In this talk, we present a new digital terrain analysis framework for digital soil mapping based on spatial data mining, referred to as the contextual elevation mapping (ConMap). Aiming at integrating different scales, which can be important at landscape scale level due to interrelations of topo- and climofunctions, it comprises local surface function approximations in terms of standard local terrain attributes as well as the incorporation of geomorphic arrangements within larger neighborhoods. In contrast to common digital terrain analysis of deriving multiple terrain attributes, ConMap is based on elevation differences from the center pixel to each pixel in a local neighborhood. These differences are then used as predictors in machine learning approaches such as Random Forests. Thus, it is not necessary to choose a specific set of terrain attributes. Additionally, possibly unknown surface functions can be taken into account, as well as larger geomorphic settings. We applied and validated the framework by predicting topsoil silt content for an area of 1150 km2 in Rhineland-Palatinate and Hesse, Germany, based on 342 samples, a 20 m resolution DEM, and neighborhood sizes up to 12 km. Cross-validation R2 values increase from 0.15 for standard digital terrain analysis to 0.61 using ConMap. This effect is due to a spatial trend in the data. As ConMap is able to map this trend and as it is based on the pedological concept of integrating scales it can be seen as a new entry to spatial prediction approaches such as Kriging or Geographically Weighted Regression. We conclude that ConMap shows a great potential for future digital soil mapping studies.

  11. 76 FR 54533 - Pipeline Safety: Issuance of Draft Decision on GexCon US, Inc. Petition for Approval of Flame...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Statement in the Federal Register published on April 11, 2000 (65 FR 19477) or visit http://www.regulations...Con US, Inc. Petition for Approval of Flame Acceleration Simulator AGENCY: Pipeline and Hazardous... a Draft Decision on GexCon US, Inc.'s petition for approval of Flame Acceleration Simulator...

  12. Papás que tienen a un niño con cáncer

    Cancer.gov

    Información práctica para los padres, cuando un hijo tiene cáncer. Sugerencias para ayudar a los niños y a los padres a salir adelante y mantenerse fuertes; junto con respuestas a preguntas que padres e hijos hacen con frecuencia.

  13. Probing of Brain States in Real-Time: Introducing the ConSole Environment.

    PubMed

    Hartmann, Thomas; Schulz, Hannah; Weisz, Nathan

    2011-01-01

    Recent years have seen huge advancements in the methods available and used in neuroscience employing EEG or MEG. However, the standard approach is to average a large number of trials for experimentally defined conditions in order to reduce intertrial-variability, i.e., treating it as a source of "noise." Yet it is now more and more accepted that trial-to-trial fluctuations bear functional significance, reflecting fluctuations of "brain states" that predispose perception and action. Such effects are often revealed in a pre-stimulus period, when comparing response variability to an invariant stimulus. However such offline analyses are disadvantageous as they are correlational by drawing conclusions in a post hoc-manner and stimulus presentation is random with respect to the feature of interest. A more direct test is to trigger stimulus presentation when the relevant feature is present. The current paper introduces Constance System for Online EEG (ConSole), a software package capable of analyzing ongoing EEG/MEG in real-time and presenting auditory and visual stimuli via internal routines. Stimulation via external devices (e.g., transcranial magnetic stimulation) or third-party software (e.g., PsyScope X) is possible by sending TTL-triggers. With ConSole it is thus possible to target the stimulation at specific brain states. In contrast to many available applications, ConSole is open-source. Its modular design enhances the power of the software as it can be easily adapted to new challenges and writing new experiments is an easy task. ConSole is already pre-equipped with modules performing standard signal processing steps. The software is also independent from the EEG/MEG system, as long as a driver can be written (currently two EEG systems are supported). Besides a general introduction, we present benchmark data regarding performance and validity of the calculations used, as well as three example applications of ConSole in different settings. ConSole can be downloaded at: http://console-kn.sf.net. PMID:21716603

  14. Probing of Brain States in Real-Time: Introducing the ConSole Environment

    PubMed Central

    Hartmann, Thomas; Schulz, Hannah; Weisz, Nathan

    2011-01-01

    Recent years have seen huge advancements in the methods available and used in neuroscience employing EEG or MEG. However, the standard approach is to average a large number of trials for experimentally defined conditions in order to reduce intertrial-variability, i.e., treating it as a source of “noise.” Yet it is now more and more accepted that trial-to-trial fluctuations bear functional significance, reflecting fluctuations of “brain states” that predispose perception and action. Such effects are often revealed in a pre-stimulus period, when comparing response variability to an invariant stimulus. However such offline analyses are disadvantageous as they are correlational by drawing conclusions in a post hoc-manner and stimulus presentation is random with respect to the feature of interest. A more direct test is to trigger stimulus presentation when the relevant feature is present. The current paper introduces Constance System for Online EEG (ConSole), a software package capable of analyzing ongoing EEG/MEG in real-time and presenting auditory and visual stimuli via internal routines. Stimulation via external devices (e.g., transcranial magnetic stimulation) or third-party software (e.g., PsyScope X) is possible by sending TTL-triggers. With ConSole it is thus possible to target the stimulation at specific brain states. In contrast to many available applications, ConSole is open-source. Its modular design enhances the power of the software as it can be easily adapted to new challenges and writing new experiments is an easy task. ConSole is already pre-equipped with modules performing standard signal processing steps. The software is also independent from the EEG/MEG system, as long as a driver can be written (currently two EEG systems are supported). Besides a general introduction, we present benchmark data regarding performance and validity of the calculations used, as well as three example applications of ConSole in different settings. ConSole can be downloaded at: http://console-kn.sf.net. PMID:21716603

  15. Medición de placas astrométricas obtenidas con el telescopio Astrográfico de La Plata

    NASA Astrophysics Data System (ADS)

    di Sisto, R. P.; Orellana, R.

    El Observatorio de La Plata cuenta con un gran número de placas de asteroides y cometas obtenidas con el telescopio astrográfico, que cubren gran parte del cielo del hemisferio sur. En 1996 se recopilaron y clasificaron 2187 placas (Beca para estudiantes de la AAA 1996) de las cuales 2031 corresponden a asteroides. Los datos de cada placa se volcaron en una base de datos creada para facilitar su manejo y preservar la información. A partir de este trabajo se revisaron los MPC electrónicos y se identificaron aquellas placas de asteroides pertenecientes a nuestra base de datos cuyos resultados no fueron publicados en los mismos. De un total de 400 placas que no aparecían publicadas sobresalía un paquete constituído por 40 placas obtenidas en 1977. Estas últimas fueron reducidas utilizando las posiciones y movimientos propios de las estrellas de referencia obtenidas del catálogo SAO 2000 dadas para el sistema FK5. Las posiciones calculadas fueron enviadas y publicadas en los Minor Planet Circulars (MPC).

  16. Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps)

    NASA Technical Reports Server (NTRS)

    Baxley, Brian T.; Johnson, William C.; Swenson, Harry; Robinson, John E.; Prevot, Thomas; Callantine, Todd; Scardina, John; Greene, Michael

    2012-01-01

    The operational goal of the ATD-1 ConOps is to enable aircraft, using their onboard FMS capabilities, to fly Optimized Profile Descents (OPDs) from cruise to the runway threshold at a high-density airport, at a high throughput rate, using primarily speed control to maintain in-trail separation and the arrival schedule. The three technologies in the ATD-1 ConOps achieve this by calculating a precise arrival schedule, using controller decision support tools to provide terminal controllers with speeds for aircraft to fly to meet times at a particular meter points, and onboard software providing flight crews with speeds for the aircraft to fly to achieve a particular spacing behind preceding aircraft.

  17. NASA KSC/AFRL Reusable Booster System (RBS) Concept of Operations (ConOps)

    NASA Technical Reports Server (NTRS)

    Zeno, Dnany; Mosteller, Ted; McCleskey, Carey; Jhnson, Robert; Hopkins, Jason; Miller, Thomas

    2010-01-01

    This slide presentation reviews the study and findings of the study on the Concept of Operations (ConOps) for Reusable Booster System (RBS) centering on rapid turnaround and launch of a two-stage partially reusable payload delivery system (i.e., 8 hours between launches). The study was to develop rapid ground processing (aircraft like concepts) and identify areas for follow-on study, technology needs, and proof-of-concept demonstrations.

  18. Precisión de las velocidades radiales obtenidas con el REOSC

    NASA Astrophysics Data System (ADS)

    González, J. F.; Lapasset, E.

    Complementando una línea de trabajo iniciada con anterioridad discutimos la estabilidad del espectrógrafo REOSC de CASLEO en DC para la medición de velocidades radiales en base al análisis de observaciones realizadas en enero y abril de 1997. En esas oportunidades obtuvimos 26 espectros de estrellas patrones y 27 espectros de 3 estrellas usadas como estrellas de referencia en nuestro programa de cúmulos abiertos. Además tomamos 26 espectros de crepúsculo con el telescopio en posiciones cubriendo el rango H=-4,+4 y δ =-90,+30. Mediante correlaciones cruzadas derivamos la velocidad de 19 órdenes en cada uno de estos espectros. En base a un análisis estadístico de los datos obtenidos discutimos la contribución de los distintos factores que afectan a la dispersión de lectura observada. En particular, la flexión del instrumento no introduciría errores significativos cuando se observa con masas de aire menores que 2.0. La dispersión de los valores de velocidad medidos para espectros de alta relación S/N de una misma estrella resultó del orden de 0.5 km/s. La comparación con los valores de velocidad publicados por distintos autores para las estrellas patrones no permite distinguir ninguna diferencia sistemática apreciable de las velocidades de CASLEO, siendo la media cuadrática de los residuos del orden de 1.0 km/s.

  19. Cómo hacer las gestiones con su plan de salud

    Cancer.gov

    Hay formas de saber si su plan de salud cubre los costos de atención médica de rutina durante un estudio clínico. Esta información puede servirle para saber con quién comunicarse para solicitar ayuda, preguntas que puede hacer y la información que debe recoger y guardar si decide participar en un estudio clínico.

  20. Structure, stratigraphy and petroleum geology of the south east Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    Fraser, A.J.; Matthews, S.J.; Lowe, S.; Todd, S.P.; Simon, P. Peel, F.J. )

    1996-01-01

    Recent exploration of the south east Nam Con Son Basin, offshore Vietnam, by BP in alliance with Statoil has involved acquisition of new seismic and well data. These new data have allowed re-evaluation of the tectono-stratigraphic development and petroleum geology, and have provided additional constraints on the regional tectonic evolution. The offshore Vietnamese basins have evolved in response to the complex relative motions of Indochina, Peninsular Malaysia, Borneo and the South China Sea during the Cenozoic. On the regional scale these motions have been accommodated by strike-slip fault development, rifting and contraction. In the Nam Con Son Basin these motions have interacted in different ways from the Palaeogene to recent. Two rifting episodes are recognized; a Palaeogene phase dominated by E-W trending extensional faults, and a Miocene phase dominated by N-S to NE-SW trending faults. The structural evolution is complicated by a pulse of mild contraction during the Middle Miocene. The sedimentary fill of the basin evolves from continental fluvio-lacustrine in the Palaeogene through to fully marine following the second phase of rifting in the Miocene. This pulsed structural and stratigraphic evolution has resulted in basinwide deposition of source, reservoir and seal facies, and produced a variety of potential trapping styles. This paper describes the hydrocarbon habitat of the south east Nam Con Son Basin within the context of the regional tectono-stratigraphic model.

  1. Structure, stratigraphy and petroleum geology of the south east Nam Con Son Basin, offshore Vietnam

    SciTech Connect

    Fraser, A.J.; Matthews, S.J.; Lowe, S.; Todd, S.P.; Simon, P. Peel, F.J.

    1996-12-31

    Recent exploration of the south east Nam Con Son Basin, offshore Vietnam, by BP in alliance with Statoil has involved acquisition of new seismic and well data. These new data have allowed re-evaluation of the tectono-stratigraphic development and petroleum geology, and have provided additional constraints on the regional tectonic evolution. The offshore Vietnamese basins have evolved in response to the complex relative motions of Indochina, Peninsular Malaysia, Borneo and the South China Sea during the Cenozoic. On the regional scale these motions have been accommodated by strike-slip fault development, rifting and contraction. In the Nam Con Son Basin these motions have interacted in different ways from the Palaeogene to recent. Two rifting episodes are recognized; a Palaeogene phase dominated by E-W trending extensional faults, and a Miocene phase dominated by N-S to NE-SW trending faults. The structural evolution is complicated by a pulse of mild contraction during the Middle Miocene. The sedimentary fill of the basin evolves from continental fluvio-lacustrine in the Palaeogene through to fully marine following the second phase of rifting in the Miocene. This pulsed structural and stratigraphic evolution has resulted in basinwide deposition of source, reservoir and seal facies, and produced a variety of potential trapping styles. This paper describes the hydrocarbon habitat of the south east Nam Con Son Basin within the context of the regional tectono-stratigraphic model.

  2. Functional characterization of Con A-responsive Lyt2-positive mouse small intestinal intraepithelial lymphocytes.

    PubMed Central

    Dillon, S B; MacDonald, T T

    1986-01-01

    The surface phenotypes of resting vs Con A-stimulated intraepithelial lymphocytes (IEL) from mouse small intestine were directly determined by immunofluorescence with double labelling. Both Thy 1.2+, Lyt 2+ and Thy 1.2+ Lyt 2- IEL underwent blastogenesis and expressed interleukin-2 (IL-2) receptors. The Lyt 2+ subsets of IEL (which represent 80% of the total cells) were isolated by panning and shown to proliferate in response to Con A and IL-2, although the frequency of responsive precursors was dramatically lower than that seen in the splenic Lyt 2+ T-cell population (1 in 500 vs 1 in 8, respectively). Con A-stimulated Lyt 2+ IEL produced lymphokines supporting the growth of the interleukin-3 (IL-3)-dependent cell line DA-1, and of the FDC-P2 cell line that proliferates in response to both IL-3 and GM-CSF. The results therefore support the possibility that Lyt 2+ IEL act as inducers of local cell-mediated immune reactions by producing haematopoietic lymphokines. PMID:3098677

  3. ConPADE: Genome Assembly Ploidy Estimation from Next-Generation Sequencing Data

    PubMed Central

    Margarido, Gabriel R. A.; Heckerman, David

    2015-01-01

    As a result of improvements in genome assembly algorithms and the ever decreasing costs of high-throughput sequencing technologies, new high quality draft genome sequences are published at a striking pace. With well-established methodologies, larger and more complex genomes are being tackled, including polyploid plant genomes. Given the similarity between multiple copies of a basic genome in polyploid individuals, assembly of such data usually results in collapsed contigs that represent a variable number of homoeologous genomic regions. Unfortunately, such collapse is often not ideal, as keeping contigs separate can lead both to improved assembly and also insights about how haplotypes influence phenotype. Here, we describe a first step in avoiding inappropriate collapse during assembly. In particular, we describe ConPADE (Contig Ploidy and Allele Dosage Estimation), a probabilistic method that estimates the ploidy of any given contig/scaffold based on its allele proportions. In the process, we report findings regarding errors in sequencing. The method can be used for whole genome shotgun (WGS) sequencing data. We also show applicability of the method for variant calling and allele dosage estimation. Results for simulated and real datasets are discussed and provide evidence that ConPADE performs well as long as enough sequencing coverage is available, or the true contig ploidy is low. We show that ConPADE may also be used for related applications, such as the identification of duplicated genes in fragmented assemblies, although refinements are needed. PMID:25880203

  4. Mound-ACT*DE*CON{sup SM} feasibility study. Phase 2: Final report

    SciTech Connect

    1994-12-01

    A portion of the abandoned Miami-Erie Canal paralleling the Greater Miami River receives the runoff and storm-water discharge from Mound Laboratory. In 1969, a low-level plutonium leak contaminated sediment as far away as 1.5 mi from the Mound site along the old canal system. An estimated one million cubic feet of sediment requires remediation. The technology being evaluated for the remediation of the low-level plutonium-238 contamination of the sediment involves two processes: washing the sediments with ACT*DE*CON{sup SM} solution to dissolve the contaminant, followed by extraction of the solution and processing with the MAG*SEP{sup SM} process to concentrate the contaminant and allow reuse of the ACT*DE*CON{sup SM} solution. The processes are being optimized for pilot-scale and field demonstration. Phase 2 of the project primarily involved identification at the laboratory scale of the optimal ACT*DE*CON{sup SM} formulation, identification of the ion-exchanger and MAG*SEP{sup SM} particles, verification of the plutonium mobility in the treated soil, and evaluation of other process parameters according to a series of tasks.

  5. The Transcription Factor Con7-1 Is a Master Regulator of Morphogenesis and Virulence in Fusarium oxysporum.

    PubMed

    Ruiz-Roldán, Carmen; Pareja-Jaime, Yolanda; González-Reyes, José Antonio; Roncero, M Isabel G

    2015-01-01

    Previous studies have demonstrated the essential role of morphogenetic regulation in Fusarium oxysporum pathogenesis, including processes such as cell-wall biogenesis, cell division, and differentiation of infection-like structures. We identified three F. oxysporum genes encoding predicted transcription factors showing significant identities to Magnaporthe oryzae Con7p, Con7-1, plus two identical copies of Con7-2. Targeted deletion of con7-1 produced nonpathogenic mutants with altered morphogenesis, including defects in cell wall structure, polar growth, hyphal branching, and conidiation. By contrast, simultaneous inactivation of both con7-2 copies caused no detectable defects in the resulting mutants. Comparative microarray-based gene expression analysis indicated that Con7-1 modulates the expression of a large number of genes involved in different biological functions, including host-pathogen interactions, morphogenesis and development, signal perception and transduction, transcriptional regulation, and primary and secondary metabolism. Taken together, our results point to Con7-1 as general regulator of morphogenesis and virulence in F. oxysporum. PMID:25271883

  6. Con-T[M8Q] potently attenuates the expression and development of morphine tolerance in mice.

    PubMed

    Ren, Baolan; Zhou, Zhijie; Liu, Zhuguo; Li, Bailin; Ou, Jie; Dai, Qiuyun

    2015-06-15

    As a variant of peptide conantokin-T (con-T), con-T[M8Q] is derived from the venom of Conus tulipa. Our previous study has demonstrated that con-T[M8Q] selectively targets N-methyl-d-aspartate receptor (NMDAR) NR2B subunit. In the present study, we determined the effects of con-T[M8Q] on the expression and development of morphine tolerance using hot plate test and acetic acid writhing test. Our results demonstrated that con-T[M8Q] could efficiently attenuate the expression and development of morphine analgesic tolerance in mice at low doses (5-20nmol/kg), and it exhibited more potent effects compared with ifenprodil, a typical small-molecule antagonist of NMDAR. In addition, low doses of con-T[M8Q] (5-20nmol/kg) did not cause drug resistance and apparent analgesic activity compared with morphine. Taken together, con-T[M8Q] could be a promising new candidate in attenuating morphine tolerance. PMID:25896730

  7. Con_A-carbone nanotube conjugate with short wave near-infrared laser ablation for tumor therapy

    NASA Astrophysics Data System (ADS)

    Lei, Huan-Yao; Peng, Ching-An; Tang, Ming-Jer; Reindhart, Kit; Szu, Harold H.

    2009-04-01

    Using the characteristics of T cell mitogen called lectin protein from the jack-beam Canavalia ensiformis Concanavalin A (Con_A) with dual activities, cytotoxicity and immunomodulation, we have shown it has a therapeutic effect on hepatoma. Injection of Con_A can eradicate the established malign tumor, because Con_A can induce tumor cell autophagic, cell-programmed death, as well as activate the effector T cells. Combined, in this paper, with the absorption exceeding the Carbon NanoTube (CNT) band-gap (?bg=~1/CNT diameter) with an active short wave near-infrared (SWIR) (1.2~1.5 micron wavelengths), which happened to be translucent to the irradiation upon animal skin, similar to that used in hospital fingertip-clamped Pulse Oxymetry. Once the Con_ACNT is guided to hepatoma cells, it is bonded and internalized into the mitochondria (MC) compartment, the cellular energy factory. Con_A has the higher specificity for tumor cells useful for targeting because of the abnormal glycosylation on tumor cells. When CNT hitch hike with Con_A, they can t together like a laser-denotable chemical missile surgically targeting at the tumor cells precisely by Con_A-guidance. We switch on SWIR laser, when the Con_A-CNT conjugated complex has been bonded and internalized to MC of malign cells and already commenced cellular programmed death. Thus, it might appear to casual readers that we have initiated an overkill, chemical drugged autophage followed with physical laser ablation, but what if we can eradicate hepatoma totally if no blue print is left behind inadvertently in case of a partial failure. We conclude that using Con_A-CNT conjugated complex targeting specifically at malign tumor cells is a novel targeted-laser-radiation therapy for tumors in mice.

  8. Estudio muestra reducción de mortalidad en hombres con cáncer de próstata de grado intermedio

    Cancer.gov

    Terapia hormonal por corto tiempo administrada en combinación con radioterapia a hombres con cáncer de próstata en estadio inicial aumentó sus posibilidades de vivir más en comparación con tratamiento de radioterapia sola, según un estudio clínico patroci

  9. Segundo Catálogo Estelar del Hemisferio Sur con Astrolabio Fotoeléctrico PAII

    NASA Astrophysics Data System (ADS)

    Manrique, W. T.; Podestá, R. C.; Alonso, E.; Actis, E. V.; Pacheco, A. M.; Bustos, G.; Lizhi, L.; Zezhi, W.; Fanmiao, Z.; Hongqi, W.; Perdomo, R.

    Recordamos que entre el Observatorio Astronómico ``Félix Aguilar'', el Observatorio Astronómico de Beijing y el Observatorio Astronómico de La Plata, se ha convenido en desarrollar un Proyecto de Investigación conjunto, para la observación sistemática de estrellas en el Hemisferio Sur, con el objeto de la elaboración de un Catálogo Estelar Global utilizando un Astrolabio Fotoeléctrico PAII del Observatorio de Beijing, que ha sido usado con éxito en la República de China. En este trabajo se presenta el Segundo Catálogo Estelar del Hemisferio Sur, derivado de las observaciones realizadas con el PAII instalado en el OAFA, durante el períiodo Febrero de 1992 a Marzo de 1997. En este lapso se han observado mas de 400000 pasajes estelares, obteniéndose las correcciones Δ α y Δ δ de 5241 estrellas del FK4, FK5, FK5 Ext., SRS, CAMC y GC. Las precisiones medias son del orden de ± 3,2 ms en ascensión recta y ±0."057 en declinación. Rango de magnitudes : 2,0 a 11,5 Rango de declinaciones : -3o a -60o Epoca Media : 1994.9 Se analizan los residuos en función de la magnitud y tipo espectral, correcciones de grupo y frecuencia de distribución Δ α y Δ δ.

  10. ConsDock: A new program for the consensus analysis of protein-ligand interactions.

    PubMed

    Paul, Nicodème; Rognan, Didier

    2002-06-01

    Protein-based virtual screening of chemical libraries is a powerful technique for identifying new molecules that may interact with a macromolecular target of interest. Because of docking and scoring limitations, it is more difficult to apply as a lead optimization method because it requires that the docking/scoring tool is able to propose as few solutions as possible and all of them with a very good accuracy for both the protein-bound orientation and the conformation of the ligand. In the present study, we present a consensus docking approach (ConsDock) that takes advantage of three widely used docking tools (Dock, FlexX, and Gold). The consensus analysis of all possible poses generated by several docking tools is performed sequentially in four steps: (i) hierarchical clustering of all poses generated by a docking tool into families represented by a leader; (ii) definition of all consensus pairs from leaders generated by different docking programs; (iii) clustering of consensus pairs into classes, represented by a mean structure; and (iv) ranking the different means starting from the most populated class of consensus pairs. When applied to a test set of 100 protein-ligand complexes from the Protein Data Bank, ConsDock significantly outperforms single docking with respect to the docking accuracy of the top-ranked pose. In 60% of the cases investigated here, ConsDock was able to rank as top solution a pose within 2 A RMSD of the X-ray structure. It can be applied as a postprocessing filter to either single- or multiple-docking programs to prioritize three-dimensional guided lead optimization from the most likely docking solution. PMID:12001231

  11. Effect of GonaCon™ vaccine on black-tailed prairie dogs: immune response and health effects.

    PubMed

    Yoder, Christi A; Miller, Lowell A

    2010-12-16

    Management of prairie dogs in the past has included poisoning, fumigants, barriers, and relocation. Because of the diverse attitudes related to prairie dog management, nonlethal methods that allow the existence of prairie dogs but help minimize damage related to population growth need to be developed. GonaCon™ is an immunocontraceptive vaccine that elicits antibodies to native GnRH; this prevents the secretion of reproductive hormones necessary for sperm and oocyte production. Prairie dogs were vaccinated with 0.1, 0.2, or 0.4 mL of the GonaCon™ emulsion intramuscularly in the upper thigh containing 100, 200, or 400 ?g GnRH conjugate, respectively. Control animals were vaccinated with 0.4 mL saline emulsion in the upper thigh. Blood samples (?1 mL) were taken from the femoral vein once pretreatment and at 1, 2, 3, 4, 6, and 15 months post-vaccination. Age (adult or juvenile) did not affect immune response to GonaCon™. Antibody titers were higher in the 200 and 400 ?L GonaCon™ groups than in the 100 ?L group, and there was no difference between the 200 and 400 ?L GonaCon™ groups. No adverse effects of GonaCon™ were noted on weight or blood chemistry parameters during the study. GonaCon™ will likely contracept prairie dogs for ?1 year in the field using either 200 or 400 ?g conjugate. GonaCon™ could be incorporated into management plans to help maintain prairie dog populations while reducing habitat degradation due to overpopulation. PMID:21055491

  12. An aggregation of pro and con evidence for medical decision support systems.

    PubMed

    Kuncheva, L

    1993-11-01

    One promising way to increase the classification accuracy of medical decision support systems is to implement heuristic combinations of pattern recognition and artificial intelligence tools. A parallel between "cognition" model and differential diagnostic task is sketched accentuating the aggregation of activating and restraining inputs and corresponding PRO and CON evidence in medicine. On the basis of this paradigm a trainable model of a fuzzy neuron is proposed which resembles some elements from the physician's decision process. An example from aviation medicine is presented which demonstrates the enhanced performance. PMID:8306621

  13. Lesbian (in)visibility in Italian Renaissance culture: Diana and other cases of donna con donna.

    PubMed

    Simons, P

    1994-01-01

    Current conceptualizations of sexual identity in the West are not necessarily useful to an historian investigating "lesbianism" in the social history and visual representations of different periods. After an overview of Renaissance documents treating donna con donna relations which examines the potentially positive effects of condemnation and silence, the paper focuses on Diana, the goddess of chastity, who bathed with her nymphs as an exemplar of female bodies preserved for heterosexual, reproductive pleasures. Yet the self-sufficiency and bodily contact sometimes represented in images of this secluded all-female gathering might suggest "deviant" responses from their viewers. PMID:7798609

  14. The pros and cons about the digital recording of Intangible Cultural Heritage and some strategies

    NASA Astrophysics Data System (ADS)

    Yang, H.

    2015-08-01

    Intangible Cultural Heritage (referred to as ICH), whose fundamental nature different from the tangible cultural heritage is "Intangible", and the related physical presence of the heritage is not the core content. Digital means have irreplaceable advantages in recording intangible and dynamic ICH resources, while it also needs flexible and rigorous recording means as a support, thus striving to maximize resources recording and protection. This article will focus on the pros and cons about the digital recording of ICH, and preliminarily discuss some strategies used in the process of recording.

  15. Nano anti-cancer drugs: pros and cons and future perspectives.

    PubMed

    Ali, Imran

    2011-02-01

    For last one decade, scientists are working for developing nano anti-cancer drugs with claim of ideal ones due to their targeted chemotherapic nature. These drugs have many beneficial properties such as targeted drug delivery and gene therapy modalities with minimum side effects. This article describes pros and cons and future perspectives of nano anti-cancer drugs. Efforts have been made to address importance, special features, toxicities (general, blood identities, immune system and environmental) and future perspectives of nano anti-cancer drugs. It was concluded that nano anti-cancer drugs may be magic bullet drugs for cancer treatment leading to bright future of the whole world. PMID:21062238

  16. Hable con Ella (Talk to Her) through the lens of gender.

    PubMed

    Yanof, Judith A

    2008-04-01

    In the 2002 film Hable con Ella (Talk to Her), Spanish writer-director Pedro Almodóvar plays with the ambiguity of gender, transcending conventional assumptions about "masculinity" and "femininity." Each of the four main characters holds complex, varied, and, in some cases, gender-bending gender identifications. The theme of gender plasticity is a prominent motif in this film. However, underlying the narrative, there is also a perverse subtext that relies on rigidly binary gender stereotypes to define relationships between men and women. Both these views of gender which operate dialectically, create a complex tapestry through which Almodóvar explores his characters' problems in attaining intimacy. PMID:18512367

  17. Zebrafish con/disp1 reveals multiple spatiotemporal requirements for Hedgehog-signaling in craniofacial development

    PubMed Central

    2009-01-01

    Background The vertebrate head skeleton is derived largely from cranial neural crest cells (CNCC). Genetic studies in zebrafish and mice have established that the Hedgehog (Hh)-signaling pathway plays a critical role in craniofacial development, partly due to the pathway's role in CNCC development. Disruption of the Hh-signaling pathway in humans can lead to the spectral disorder of Holoprosencephaly (HPE), which is often characterized by a variety of craniofacial defects including midline facial clefting and cyclopia [1,2]. Previous work has uncovered a role for Hh-signaling in zebrafish dorsal neurocranium patterning and chondrogenesis, however Hh-signaling mutants have not been described with respect to the ventral pharyngeal arch (PA) skeleton. Lipid-modified Hh-ligands require the transmembrane-spanning receptor Dispatched 1 (Disp1) for proper secretion from Hh-synthesizing cells to the extracellular field where they act on target cells. Here we study chameleon mutants, lacking a functional disp1(con/disp1). Results con/disp1 mutants display reduced and dysmorphic mandibular and hyoid arch cartilages and lack all ceratobranchial cartilage elements. CNCC specification and migration into the PA primorida occurs normally in con/disp1 mutants, however disp1 is necessary for post-migratory CNCC patterning and differentiation. We show that disp1 is required for post-migratory CNCC to become properly patterned within the first arch, while the gene is dispensable for CNCC condensation and patterning in more posterior arches. Upon residing in well-formed pharyngeal epithelium, neural crest condensations in the posterior PA fail to maintain expression of two transcription factors essential for chondrogenesis, sox9a and dlx2a, yet continue to robustly express other neural crest markers. Histology reveals that posterior arch residing-CNCC differentiate into fibrous-connective tissue, rather than becoming chondrocytes. Treatments with Cyclopamine, to inhibit Hh-signaling at different developmental stages, show that Hh-signaling is required during gastrulation for normal patterning of CNCC in the first PA, and then during the late pharyngula stage, to promote CNCC chondrogenesis within the posterior arches. Further, loss of disp1 disrupted normal expression of bapx1 and gdf5, markers of jaw joint patterning, thus resulting in jaw joint defects in con/disp1 mutant animals. Conclusion This study reveals novel requirements for Hh-signaling in the zebrafish PA skeleton and highlights the functional diversity and differential sensitivity of craniofacial tissues to Hh-signaling throughout the face, a finding that may help to explain the spectrum of human facial phenotypes characteristic of HPE. PMID:19948063

  18. Accessory cell functions of dendritic cells and macrophages in the thymic T-cell response to Con A.

    PubMed Central

    Hirayama, Y; Inaba, K; Komatsubara, S; Yoshida, K; Kawai, J; Naito, K; Muramatsu, S

    1987-01-01

    Accessory cell (A cell) functions of splenic dendritic cells (DC) and peritoneal macrophages (M phi) were investigated in the Con A-stimulated proliferative response of thymic T cells. DC were more efficient as A cells than M phi in respect of their necessary cell numbers, Con A dose and culture period required for optimal response. Con A-pulsed T cells proliferated with the aid of lymphocyte activating factor(s) (LAF) derived from M phi, even in the apparent absence of A cells. Con A-pulsed M phi were superior to unpulsed M phi in the secretion of LAF to induce a high response of Con A-pulsed T cells. A cell activity of M phi in different preparations appeared to parallel the ability to secrete LAF, and was totally abolished by fixation of M phi with paraformaldehyde. The fixation of DC, however, resulted in only a partial reduction of the A cell activity. These results argue that both DC and M phi can serve as A cells in the T-cell response to Con A, but that the mechanism to manifest A cell activity is somewhat different between DC and M phi. PMID:3499378

  19. PDP-CON: prediction of domain/linker residues in protein sequences using a consensus approach.

    PubMed

    Chatterjee, Piyali; Basu, Subhadip; Zubek, Julian; Kundu, Mahantapas; Nasipuri, Mita; Plewczynski, Dariusz

    2016-04-01

    The prediction of domain/linker residues in protein sequences is a crucial task in the functional classification of proteins, homology-based protein structure prediction, and high-throughput structural genomics. In this work, a novel consensus-based machine-learning technique was applied for residue-level prediction of the domain/linker annotations in protein sequences using ordered/disordered regions along protein chains and a set of physicochemical properties. Six different classifiers-decision tree, Gaussian naïve Bayes, linear discriminant analysis, support vector machine, random forest, and multilayer perceptron-were exhaustively explored for the residue-level prediction of domain/linker regions. The protein sequences from the curated CATH database were used for training and cross-validation experiments. Test results obtained by applying the developed PDP-CON tool to the mutually exclusive, independent proteins of the CASP-8, CASP-9, and CASP-10 databases are reported. An n-star quality consensus approach was used to combine the results yielded by different classifiers. The average PDP-CON accuracy and F-measure values for the CASP targets were found to be 0.86 and 0.91, respectively. The dataset, source code, and all supplementary materials for this work are available at https://cmaterju.org/cmaterbioinfo/ for noncommercial use. PMID:26969678

  20. Quick fix or long-term cure? Pros and cons of bariatric surgery

    PubMed Central

    Madura, James A.

    2012-01-01

    The past decade has seen an enormous increase in the number of bariatric, or weight loss, operations performed. This trend is likely to continue, mirroring the epidemic of obesity around the world and its rising prevalence among children. Bariatric surgery is considered by many to be the most effective treatment for obesity in terms of maintenance of long-term weight loss and improvement in obesity-related comorbid conditions. Although overly simplified, the primary mechanisms of the surgical interventions currently utilized to treat obesity are the creation of a restrictive or malabsorptive bowel anatomy. Operations based on these mechanisms include the laparoscopic adjustable gastric band and laparoscopic vertical sleeve gastrectomy (considered primarily restrictive operations), the laparoscopic biliopancreatic diversion with or without a duodenal switch (primarily malabsorptive operation), and the laparoscopic Roux-en-Y gastric bypass (considered a combination restrictive and selective malabsorptive procedure). Each operation has pros and cons. Important considerations, for the patient and surgeon alike, in the decision to proceed with bariatric surgery include the technical aspects of the operation, postoperative complications including long-term nutritional problems, magnitude of initial and sustained weight loss desired, and correction of obesity-related comorbidities. Herein, the pros and cons of the contemporary laparoscopic bariatric operations are reviewed and ongoing controversies relating to bariatric surgery are discussed: appropriate patient selection, appropriate operation selection for an individual patient, surgeon selection, and how to measure success after surgery. PMID:23091563

  1. RETOS EN LA INTERVENCIÓN CON ADOLESCENTES PUERTORRIQUEÑOS/AS QUE MANIFIESTAN COMPORTAMIENTO SUICIDA*

    PubMed Central

    Vélez, Yovanska Duarté; Dávila, Paloma Torres; Hernández, Samariz Laboy

    2015-01-01

    Presentamos un estudio de caso de una adolescente puertorriqueña con comportamiento suicida. Esta comenzó una Terapia Socio Cognitivo-Conductual para el Comportamiento Suicida (TSCC-CS) de tipo ambulatorio luego de una hospitalización por intento suicida. La TSCC-CS incorpora una perspectiva ecológica y de desarrollo a la terapia cognitivo-conductual. Inicialmente mostró baja autoestima y severos síntomas depresivos y de ansiedad. Al finalizar el tratamiento, manifestó un cambio significativo en su sintomatología clínica y evidenció una mejoría en sus destrezas de manejo. No presentó ideas suicidas durante meses previos, ni durante el seguimiento. El análisis de este caso permitió realizar cambios en el protocolo de tratamiento, particularmente en las sesiones de familia y de comunicación con el fin de aumentar la viabilidad del tratamiento. PMID:26702337

  2. Reliability of knee extension and flexion measurements using the Con-Trex isokinetic dynamometer.

    PubMed

    Maffiuletti, Nicola A; Bizzini, Mario; Desbrosses, Kevin; Babault, Nicolas; Munzinger, Urs

    2007-11-01

    The aim of this study was to evaluate the reliability of isokinetic and isometric assessments of the knee extensor and the flexor muscle function using the Con-Trex isokinetic dynamometer. Thirty healthy subjects (15 males, 15 females) were tested and retested 7 days later for maximal strength (isokinetic peak torque, work, power and angle of peak torque as well as isometric maximal voluntary contraction torque and rate of torque development) and fatigue (per cent loss and linear slope of torque and work across a series of 20 contractions). For both the knee extensor and the flexor muscle groups, all strength data - except angle of peak torque - demonstrated moderate-to-high reliability, with intraclass correlation coefficients (ICC) higher than 0.86. The highest reliability was observed for concentric peak torque of the knee extensor muscles (ICC = 0.99). Test-retest reliability of fatigue variables was moderate for the knee extensor (ICC range 0.84-0.89) and insufficient-to-moderate for the knee flexor muscles (ICC range 0.78-0.81). The more reliable index of muscle fatigue was the linear slope of the decline in work output. These findings establish the reliability of isokinetic and isometric measurements using the Con-Trex machine. PMID:17944656

  3. Quick fix or long-term cure? Pros and cons of bariatric surgery.

    PubMed

    Madura, James A; Dibaise, John K

    2012-01-01

    The past decade has seen an enormous increase in the number of bariatric, or weight loss, operations performed. This trend is likely to continue, mirroring the epidemic of obesity around the world and its rising prevalence among children. Bariatric surgery is considered by many to be the most effective treatment for obesity in terms of maintenance of long-term weight loss and improvement in obesity-related comorbid conditions. Although overly simplified, the primary mechanisms of the surgical interventions currently utilized to treat obesity are the creation of a restrictive or malabsorptive bowel anatomy. Operations based on these mechanisms include the laparoscopic adjustable gastric band and laparoscopic vertical sleeve gastrectomy (considered primarily restrictive operations), the laparoscopic biliopancreatic diversion with or without a duodenal switch (primarily malabsorptive operation), and the laparoscopic Roux-en-Y gastric bypass (considered a combination restrictive and selective malabsorptive procedure). Each operation has pros and cons. Important considerations, for the patient and surgeon alike, in the decision to proceed with bariatric surgery include the technical aspects of the operation, postoperative complications including long-term nutritional problems, magnitude of initial and sustained weight loss desired, and correction of obesity-related comorbidities. Herein, the pros and cons of the contemporary laparoscopic bariatric operations are reviewed and ongoing controversies relating to bariatric surgery are discussed: appropriate patient selection, appropriate operation selection for an individual patient, surgeon selection, and how to measure success after surgery. PMID:23091563

  4. Co-N Decorated Hierarchically Porous Graphene Aerogel for Efficient Oxygen Reduction Reaction in Acid.

    PubMed

    Fu, Xiaogang; Choi, Ja-Yeon; Zamani, Pouyan; Jiang, Gaopeng; Hoque, Md Ariful; Hassan, Fathy Mohamed; Chen, Zhongwei

    2016-03-16

    Nitrogen-functionalized graphene materials have been demonstrated as promising electrocatalyst for the oxygen reduction reaction (ORR), owning to their respectable activity and excellent stability in alkaline electrolyte. However, they exhibit unacceptable catalytic activity in acid medium. Here, a hierarchically porous Co-N functionalized graphene aerogel is prepared as an efficient catalyst for the ORR in acid electrolyte. In the preparation process, polyaniline (PANI) is introduced as a pore-forming agent to aid in the self-assembly of graphene species into a porous aerogel networks, and a nitrogen precursor to induce in situ nitrogen doping. Therefore, a Co-N decorated graphene aerogel framework with a large surface area (485 m(2) g(-1)) and an abundance of meso/macropores is effectively formed after heat treatment. Such highly desired structures can not only expose sufficient active sites for the ORR but also guarantee the fast mass transfer in the catalytic process, which provides significant catalytic activity with positive onset and half wave potentials, low hydrogen peroxide yield, high resistance to methanol crossover, and remarkable stability that is comparable to commercial Pt/C in acid medium. PMID:26937737

  5. Uso de Sustancias en Mujeres con Desventaja Social: Riesgo para el Contagio de VIH/SIDA

    PubMed Central

    Cianelli, R.; Ferrer, L; Bernales, M.; Miner, S.; Irarrázabal, L.; Molina, Y.

    2009-01-01

    Antecedentes La caracterización epidemiológica en Chile apunta a feminización, pauperización y heterosexualización de la epidemia del VIH, lo que implica un mayor riesgo para las mujeres en desventaja social. Si a esto se suma la utilización de sustancias, la vulnerabilidad de este grupo frente al VIH/SIDA aumenta. Objetivo Describir el uso de sustancias en mujeres con desventaja social e identificar factores de riesgo de contagio de VIH, asociados a este consumo. Material y Método 52 mujeres fueron entrevistadas como parte del proyecto “Testeando una intervención en prevención de VIH/SIDA en mujeres chilenas” GRANT # RO1 TW 006977. Se describen variables sociodemográficas y de consumo de sustancias a través de estadísticas descriptivas y se analiza la relación entre variables a través de pruebas de correlación. Resultados Los resultados indican un perfil sociodemográfico que sitúa a las mujeres en situación de vulnerabilidad frente al contagio de VIH/SIDA, con alto índice de uso de sustancias que acentúa el riesgo. Conclusiones Los hallazgos apuntan a la necesidad de considerar intervenciones que se enfoquen en la prevención de VIH en mujeres, abordando los riesgos asociados al consumo de sustancias. PMID:21197380

  6. Feeding of grey squirrels (Sciurus carolinensis) with the contraceptive agent DiazaCon™: effect on cholesterol, hematology, and blood chemistry.

    PubMed

    Yoder, Christi A; Mayle, Brenda A; Furcolow, Carol A; Cowan, David P; Fagerstone, Kathleen A

    2011-12-01

    Grey squirrels (Sciurus carolinensis) are an invasive species in Britain and Italy. They have replaced native red squirrels (Sciurus vulgaris) throughout most of Britain, and cause damage to trees. Currently, lethal control is used to manage grey squirrel populations in Britain, but nonlethal methods might be more acceptable to the public. One such method is contraception with 20,25-diazacholesterol dihydrochloride (DiazaCon™). DiazaCon™ inhibits the conversion of desmosterol to cholesterol, resulting in increasing desmosterol concentrations and decreasing cholesterol concentrations. Because cholesterol is needed for the synthesis of steroid reproductive hormones, such as progesterone and testosterone, inhibition of cholesterol synthesis indirectly inhibits reproduction. Desmosterol is used as a marker of efficacy in laboratory studies with species that do not reproduce readily in captivity. Grey squirrels were gavaged with a DiazaCon™ solution for 2 days, and then fed DiazaCon™-coated peanuts for an additional 8 days at target doses of 50 and 100 mg DiazaCon™ per kg body weight. There was a significant difference in cholesterol concentrations in the treatment groups compared to the control group. Cholesterol was reduced by ? 40% for 2 months in both treatment groups. There were no differences among groups with respect to blood chemistry and hematology parameters, and mean values are reported. The mean overall dose of DiazaCon™ received was 29.0 ± 1.6 and 55.3 ± 4.3 mg/kg in the low (50 mg/kg) and high dose (100 mg/kg) groups, respectively. DiazaCon™ might provide an effective, acceptable alternative to lethal control. PMID:22182332

  7. Overcoming the aggregation problem: a new type of fluorescent ligand for ConA-based glucose sensing.

    PubMed

    Cummins, Brian M; Li, Mingchien; Locke, Andrea K; Birch, David J S; Vigh, Gyula; Coté, Gerard L

    2015-01-15

    Competitive binding assays based on the lectin Concanavalin A (ConA) have displayed significant potential to serve in continuous glucose monitoring applications. However, to date, this type of fluorescent, affinity-based assay has yet to show the stable, glucose predictive capabilities that are required for such an application. This instability has been associated with the extensive crosslinking between traditionally-used fluorescent ligands (presenting multiple low-affinity moieties) and ConA (presenting multiple binding sites) in free solution. The work herein introduces the design and synthesis of a new type of fluorescent ligand that can avoid this aggregation and allow the assay to be sensitive across the physiologically relevant glucose concentration range. This fluorescent ligand (APTS-MT) presents a single high-affinity trimannose moiety that is recognized by ConA's full binding site and a fluorophore that can effectively track the ligand's equilibrium binding via fluorescent anisotropy. This is confirmed by comparing its measured fluorescent lifetime to experimentally-determined rotational correlation lifetimes of the free and bound populations. Using an assay comprised of 200 nM APTS-MT and 1 µM ConA, the fluorescence anisotropy capably tracks the concentration of monosaccharides that are known to bind to ConA's primary binding site, and the assay displays a MARD of 6.5% across physiologically relevant glucose concentrations. Ultimately, this rationally-designed fluorescent ligand can facilitate the realization of the full potential of ConA-based glucose sensing assays and provide the basis for a new set of competing ligands to be paired with ConA. PMID:25058939

  8. A con-focal setup for micro-XRF experiments using diamond anvil cells

    NASA Astrophysics Data System (ADS)

    Wilke, Max; Rickers, Karen; Vincze, Laszlo; Schmidt, Christian; Borchert, Manuela; Pascarelli, Sakura

    2010-05-01

    In this contribution we introduce an experimental setup to perform con-focal micro X-ray fluorescence measurements in situ in samples at high temperatures and pressures in diamond anvil cells (DAC) (e.g. Schmidt et al. 2007). The con-focal arrangement is used to suppress the background in X-ray fluorescence (XRF) spectra that stems from elastic and inelastic scattering of the diamond anvils. The setup is based on a focusing optic in the incident beam that reaches a spot of 5-10 ?m and a focusing poly-capillary in front of an energy-dispersive solid-state detector. The detector poly-capillary is designed to work at a very long working distance of 50 mm in order to collect the radiation from the center of the DAC at 90° to the incident beam. The probing volume is defined by the two foci and has a size of ca. 300 ?m at 8 keV and 150 ?m at 19 keV as measured by scans through thin metal foils. Comparison of XRF spectra acquired with a usual detector collimator and spectra recorded with the detector capillary shows a strong suppression of XRF signal generated outside the probed volume, i.e. XRF from the gasket material and signal from elastic and Compton scattering by the diamond anvils. The ratio of the Zr K-alpha fluorescence peak to the peak of the Compton scattering changes from 0.5 (collimator) to 1.26 (detector capillary) for a ca. 1000 ppm Zr standard solution and an incident beam energy of 20 keV. For a standard solution containing ca. 1000 ppm Hf, the ratio of the L-alpha to the Compton signal increases to 6 using the detector capillary and an incident beam energy of 9.7 keV. Thus, the con-focal setup substantially improves the fluorescence to background ratio. This will result in higher sensitivities for dilute elements in the sample chamber of the DAC. Furthermore, the possibilities of interference of the sample's signal with signal from the sample environment are greatly reduced. In a broader sense, the setup can also be applied to other confined samples that require long working distances. Schmidt et al. (2007) Lithos 95, 87-102

  9. Perceived pros and cons of smoking and quitting in hard-core smokers: a focus group study

    PubMed Central

    2014-01-01

    Background In the last decade, so-called hard-core smokers have received increasing interest in research literature. For smokers in general, the study of perceived costs and benefits (or ‘pros and cons’) of smoking and quitting is of particular importance in predicting motivation to quit and actual quitting attempts. Therefore, this study aims to gain insight into the perceived pros and cons of smoking and quitting in hard-core smokers. Methods We conducted 11 focus group interviews among current hard-core smokers (n = 32) and former hard-core smokers (n = 31) in the Netherlands. Subsequently, each participant listed his or her main pros and cons in a questionnaire. We used a structural procedure to analyse the data obtained from the group interviews and from the questionnaires. Results Using the qualitative data of both the questionnaires and the transcripts, the perceived pros and cons of smoking and smoking cessation were grouped into 6 main categories: Finance, Health, Intrapersonal Processes, Social Environment, Physical Environment and Food and Weight. Conclusions Although the perceived pros and cons of smoking in hard-core smokers largely mirror the perceived pros and cons of quitting, there are some major differences with respect to weight, social integration, health of children and stress reduction, that should be taken into account in clinical settings and when developing interventions. Based on these findings we propose the ‘Distorted Mirror Hypothesis’. PMID:24548463

  10. What to consider when regulating electronic cigarettes: Pros, cons and unintended consequences.

    PubMed

    Caponnetto, Pasquale; Saitta, Daniela; Sweanor, David; Polosa, Riccardo

    2015-06-01

    Many public health experts, medical research societies, large health organizations and policy makers have expressed concerns about the increased popularity of electronic cigarettes and have pushed for more restrictive measures ranging from complete bans to tight regulations of these products either as medicines or as tobacco products. But these concerns have never been adequately qualified nor quantified. Without judicious assessment and thorough evaluation, regulations may have unintended consequences that can do more damage than good in public health terms. In this article, we will appraise the existing prominent regulatory frameworks for e-cigarettes, namely, general consumer product, medicinal product and tobacco product regulation, to highlight their pros and cons. Moreover, we provide concrete examples of the unintended consequences which may arise from inappropriate regulatory action. PMID:25857204

  11. Nest destruction elicits indiscriminate con- versus heterospecific brood parasitism in a captive bird

    PubMed Central

    Shaw, Rachael C; Feeney, William E; Hauber, Mark E

    2014-01-01

    Following nest destruction, the laying of physiologically committed eggs (eggs that are ovulated, yolked, and making their way through the oviduct) in the nests of other birds is considered a viable pathway for the evolution of obligate interspecific brood parasitism. While intraspecific brood parasitism in response to nest predation has been experimentally demonstrated, this pathway has yet to be evaluated in an interspecific context. We studied patterns of egg laying following experimental nest destruction in captive zebra finches, Taeniopygia guttata, a frequent intraspecific brood parasite. We found that zebra finches laid physiologically committed eggs indiscriminately between nests containing conspecific eggs and nests containing heterospecific eggs (of Bengalese finches, Lonchura striata vars. domestica), despite the con- and heterospecific eggs differing in both size and coloration. This is the first experimental evidence that nest destruction may provide a pathway for the evolution of interspecific brood parasitism in birds. PMID:25512846

  12. Nest destruction elicits indiscriminate con- versus heterospecific brood parasitism in a captive bird.

    PubMed

    Shaw, Rachael C; Feeney, William E; Hauber, Mark E

    2014-12-01

    Following nest destruction, the laying of physiologically committed eggs (eggs that are ovulated, yolked, and making their way through the oviduct) in the nests of other birds is considered a viable pathway for the evolution of obligate interspecific brood parasitism. While intraspecific brood parasitism in response to nest predation has been experimentally demonstrated, this pathway has yet to be evaluated in an interspecific context. We studied patterns of egg laying following experimental nest destruction in captive zebra finches, Taeniopygia guttata, a frequent intraspecific brood parasite. We found that zebra finches laid physiologically committed eggs indiscriminately between nests containing conspecific eggs and nests containing heterospecific eggs (of Bengalese finches, Lonchura striata vars. domestica), despite the con- and heterospecific eggs differing in both size and coloration. This is the first experimental evidence that nest destruction may provide a pathway for the evolution of interspecific brood parasitism in birds. PMID:25512846

  13. Phase transition and chemical decomposition of shocked CO-N2 mixture.

    PubMed

    Chen, GuanYu; Jiang, XiaoXu; Cheng, XinLu; Zhang, Hong

    2012-08-01

    Using quantum molecular dynamics simulations based on density functional theory including dispersion corrections (DFT-D), we have studied the thermophysical properties of liquid carbon monoxide and nitrogen (CO-N(2)) mixture under extreme conditions. Density functional theory (DFT) method significantly overestimates the pressure as compared to DFT-D. It is demonstrated that the van der Waals (vdW) interaction has a negative contribution to the pressure and tends to reduce the overestimation of the equilibrium volume. We also demonstrate that a negative slope of Hugoniot curve could possibly be caused by both the absorption of dissociation energy and the uncertainties in composition. As density and temperature increase along the Hoguniot curve, the system appears to undergo a continuous transition and provides for a much richer set of dissociation products. The influence of dissociated carbon and oxygen atoms on nitrogen molecules is also discussed. PMID:22894361

  14. Space and terrestrial media for military communications - Technical pros and cons

    NASA Astrophysics Data System (ADS)

    Dharamsi, Manoj T.; Reilly, James F.; Hawrylko, Warren P.

    Technical pros and cons are presented for space and terrestrial media for defense-wide long-haul military communications. Defense-wide military space communications include use of leased commercial satellite capability in addition to the government-owned Defense Satellite Communications System (DSCS). The terrestrial communications include use of troposcatter, HF radios, line-of-sight microwave, and metallic and fiber-optic cables. The current usage, capacity, cost, and other attributes of these media are examined. Current trends and future uses of the space and terrestrial media for military communications are discussed. It is concluded that military communications can continue best by using a mix of both space and terrestrial media.

  15. Multipotent (adult) and pluripotent stem cells for heart regeneration: what are the pros and cons?

    PubMed

    Liao, Song-Yan; Tse, Hung-Fat

    2013-01-01

    Heart failure after myocardial infarction is the leading cause of mortality and morbidity worldwide. Existing medical and interventional therapies can only reduce the loss of cardiomyocytes during myocardial infarction but are unable to replenish the permanent loss of cardiomyocytes after the insult, which contributes to progressive pathological left ventricular remodeling and progressive heart failure. As a result, cell-based therapies using multipotent (adult) stem cells and pluripotent stem cells (embryonic stem cells or induced pluripotent stem cells) have been explored as potential therapeutic approaches to restore cardiac function in heart failure. Nevertheless, the optimal cell type with the best therapeutic efficacy and safety for heart regeneration is still unknown. In this review, the potential pros and cons of different types of multipotent (adult) stem cells and pluripotent stem cells that have been investigated in preclinical and clinical studies are reviewed, and the future perspective of stem cell-based therapy for heart regeneration is discussed. PMID:24476362

  16. The new human papillomavirus (HPV) vaccine: pros and cons for pediatric and adolescent health.

    PubMed

    Thomas, Tami L

    2008-01-01

    The new human papillomavirus (HPV) vaccine is a research breakthrough for pediatric/adolescent health to prevent cervical cancer and related morbidity. The annual heath care cost for the treatment of cervical cancer and genital warts is estimated to be more than three billion dollars a year. The new HPV vaccine has incredible potential to improve reproductive health promotion, reduce health care costs, and close health care disparity gaps. However, issues both for and against the new HPV vaccine, including mandating vaccination, high cost of the vaccine, the short duration of protection offered, and the perceived promotion of sexual activity, cause confusion. Pediatric nurses, including those in advanced practice, benefit by understanding the pros and cons of these issues in advocating for their patients. PMID:19051848

  17. From in vitro Experiments to in vivo and Clinical Studies; Pros and Cons.

    PubMed

    Saeidnia, Soodabeh; Manayi, Azadeh; Abdollahi, Mohammad

    2015-01-01

    Biomedical investigators use different methods including experimental animals, tissue, and cell cultures as well as computational simulations and clinical studies finding the ways to treat human diseases and disorders. All the mentioned procedures have their own advantages and disadvantages. For instance although animal models provide some drawbacks like difference in biokinetics parameters or extrapolation of results to human, they are more reliable than in vitro tests. The disadvantage of the in vitro procedures is that they are mostly performed on cancerous cell lines that have a substantially abnormal function. Furthermore, although in vitro models are fruitfully used in biological fields, finding an end point, the initial aim of chemical attack, and extrapolation of the effects to the human are some real weaknesses. Absence of biokinetics in in vitro methods may lead to a misinterpretation of the data. The present review has criticized the pros and cons of both methods, especially in the fields of pharmacology, toxicology, and medical sciences. PMID:26778084

  18. La salud en personas con discapacidad intelectual en España: estudio europeo POMONA-II

    PubMed Central

    Martínez-Leal, Rafael; Salvador-Carulla, Luis; Gutiérrez-Colosía, Mencía Ruiz; Nadal, Margarida; Novell-Alsina, Ramón; Martorell, Almudena; González-Gordón, Rodrigo G.; Mérida-Gutiérrez, M. Reyes; Ángel, Silvia; Milagrosa-Tejonero, Luisa; Rodríguez, Alicia; García-Gutiérrez, Juan C.; Pérez-Vicente, Amado; García-Ibáñez, José; Aguilera-Inés, Francisco

    2011-01-01

    Introducción Estudios internacionales demuestran que existe un patrón diferenciado de salud y una disparidad en la atención sanitaria entre personas con discapacidad intelectual (DI) y población general. Objetivo Obtener datos sobre el estado de salud de las personas con DI y compararlos con datos de población general. Pacientes y métodos Se utilizó el conjunto de indicadores de salud P15 en una muestra de 111 sujetos con DI. Los datos de salud encontrados se compararon según el tipo de residencia de los sujetos y se utilizó la Encuesta Nacional de Salud 2006 para comparar estos datos con los de la población general. Resultados La muestra con DI presentó 25 veces más casos de epilepsia y el doble de obesidad. Un 20% presentó dolor bucal, y existió una alta presencia de problemas sensoriales, de movilidad y psicosis. Sin embargo, encontramos una baja presencia de patologías como la diabetes, la hipertensión, la osteoartritis y la osteoporosis. También presentaron una menor participación en programas de prevención y promoción de la salud, un mayor número de ingresos hospitalarios y un uso menor de los servicios de urgencia. Conclusiones El patrón de salud de las personas con DI difiere del de la población general, y éstas realizan un uso distinto de los servicios sanitarios. Es importante el desarrollo de programas de promoción de salud y de formación profesional específicamente diseñados para la atención de personas con DI, así como la implementación de encuestas de salud que incluyan datos sobre esta población. PMID:21948011

  19. Future of clip-on weapon sights: pros and cons from an applications perspective

    NASA Astrophysics Data System (ADS)

    Knight, C. Reed; Greenslade, Ken; Francisco, Glen

    2015-05-01

    US Domestic, International, allied Foreign National Warfighters and Para-Military First Responders (Police, SWAT, Special Operations, Law Enforcement, Government, Security and more) are put in harm's way all the time. To successfully complete their missions and return home safely are the primary goals of these professionals. Tactical product improvements that affect mission effectiveness and solider survivability are pivotal to understanding the past, present and future of Clip-On in-line weapon sights. Clip-On Weapon Sight (WS) technology was deemed an interim solution by the US Government for use until integrated and fused (day/night multi-sensor) Weapon Sights (WSs) were developed/fielded. Clip-On has now become the solution of choice by Users, Warriors, Soldiers and the US Government. SWaP-C (size, weight and power -cost) has been improved through progressive advances in Clip-On Image Intensified (I2), passive thermal, LL-CMOS and fused technology. Clip-On Weapon Sights are now no longer mounting position sensitive. Now they maintain aim point boresight, so they can be used for longer ranges with increased capabilities while utilizing the existing zeroed weapon and daysight optic. Active illuminated low-light level (both analog I2 and digital LL-CMOS) imaging is rightfully a real-world technology, proven to deliver daytime and low-light level identification confidence. Passive thermal imaging is also a real-world technology, proven to deliver daytime, nighttime and all-weather (including dirty battlefield) target detection confidence. Image processing detection algorithms with intelligent analytics provide documented promise to improve confidence by reducing Users, Warriors and Soldiers' work-loads and improving overall system engagement solution outcomes. In order to understand the future of Clip-On in-line weapon sights, addressing pros and cons, this paper starts with an overview of historical weapon sight applications, technologies and stakeholder decisions driving milestone events that helped shape the Clip-On weapon sight industry. Then, this paper systematically reviews current attributes of integrated multispectral wavelength electro-optical imaging systems that successfully (and sometimes unsuccessfully) shape today's Warrior, Soldier and User's net-capabilities. Finally, this paper explores the evolution, pros and cons, of future Clip-On weapon sights, from a manufacturing and real world applications perspective for tomorrow's military soldier and paramilitary first responder.

  20. Economic and Ethical Consequences of Natural Hazards in Alpine Valleys (EE-Con)

    NASA Astrophysics Data System (ADS)

    Ortner, Florian; Brantl, Dirk; Meyer, Lukas; Steininger, Karl; Sass, Oliver

    2015-04-01

    The Alps and their population are particularly vulnerable to geomorphological and hydrological hazards and this problem might be amplified by ongoing climate change. Natural disasters cause severe monetary damage which often leads to the difficult question whether it socially pays to protect settlements at high costs or whether alternatively settlement areas should better be abandoned. By investigations in the Johnsbachtal and the Kleinsölktal (Styria), the interdisciplinary project "Economic and Ethical Consequences of Natural Hazards in Alpine Valleys" (EE-Con), funded by the Austrian Academy of Sciences, seeks to answer the following questions: (1) Are natural hazards and associated damages in fact increasing, and is this due to meteorological triggers, to anthropogenic factors or to internal process dynamics? (2) What is the perception and knowledge of local people, how is risk and risk prevention communicated? (3) What is the respective cost ratio between protection infrastructure, soft measures of adaptation and other options (e.g. reduction of settlement area)? (4) What legitimate claims to compensation do people have, how far does societal responsibility go and where does individual responsibility start if parts of the settlement area had to be abandoned? These questions will be tackled in an interdisciplinary cooperation between geography, economics and normative theory (philosophy). EE-Con will follow broadly the path of risk analysis and risk assessment, focusing on the temporal dimension (past - present - future) with the aim to unravel the history of natural hazards in the areas and to analyse the economic values involved. In the following, natural hazard scenarios for the future (2050 and 2100) will be developed considering the economic consequences. Besides this, the project deals with local knowledge, risk perception and risk communication, which will be investigated via group interviews and stakeholder workshops and be integrated into a human-ecological model. Therefore, local people and stakeholders are going to be involved in a transdisciplinary approach from the start of the project. The geographic and economic information will then be used to find proper weighing mechanisms answering the normative questions mentioned above. The questions of enduring the respective costs and of responsibility for protecting the respective entitlements will be investigated from an ethical, a legal, and an economic viewpoint. The overall outcome of the results should provide an integrative view on the economic and ethical consequences of natural hazards in alpine valleys.

  1. Un programa innovador busca ayudar a las personas que cuidan a pacientes con cáncer

    Cancer.gov

    Artículo sobre un programa educativo del City of Hope Cancer Center que ofrece a los profesionales de salud la información y las herramientas necesarias para ayudar a los familiares a saber cómo cuidarse a si mismos y a sus seres queridos con cáncer.

  2. Comparative immunoprophylactic efficacy of Haemonchus contortus recombinant enolase (rHcENO) and Con A purified native glycoproteins in sheep.

    PubMed

    Kalyanasundaram, Aravindan; Jawahar, Shabnam; Ilangopathy, Manikkavasagan; Palavesam, Azahahianambi; Raman, Muthusamy

    2015-07-01

    Haemonchus contortus is the most economically important blood feeding nematode parasite of sheep and goats all over the world. Enolase in helminth parasites is a multi-functional enzyme which involves in glycolysis and host tissue invasion. In this study, the recombinant H. contortus enolase (rHcENO) was evaluated for its immunoprophylactic efficacy in sheep along with Con A purified native glycoproteins in a vaccine challenge trial. Group I and Group II experimental sheep were immunized thrice with rHcENO and Con A purified native glycoproteins along with Montanide ISA 61 VG adjuvant. The animals were challenged with 5000?L3 stage active H. contortus larvae after 21 days of third immunization. A significant increase in the IgG titre was observed in rHcENO and Con A purified native glycoproteins immunized animals as compared to the control animals. Immunoprotective efficacy of Con A purified native glycoproteins was comparatively higher than rHcENO antigen. PMID:25913090

  3. iPathCons and iPathDB: an improved insect pathway construction tool and the database

    PubMed Central

    Zhang, Zan; Yin, Chuanlin; Liu, Ying; Jie, Wencai; Lei, Wenjie; Li, Fei

    2014-01-01

    Insects are one of the most successful animal groups on earth. Some insects, such as the silkworm and honeybee, are beneficial to humans, whereas others are notorious pests of crops. At present, the genomes of 38 insects have been sequenced and made publically available. In addition, the transcriptomes of dozens of insects have been sequenced. As gene data rapidly accumulate, constructing the pathway of molecular interactions becomes increasingly important for entomological research. Here, we developed an improved tool, iPathCons, for knowledge-based construction of pathways from the transcriptomes or the official gene sets of genomes. Considering the high evolution diversity in insects, iPathCons uses a voting system for Kyoto Encyclopedia of Genes and Genomes Orthology assignment. Both stand-alone software and a web server of iPathCons are provided. Using iPathCons, we constructed the pathways of molecular interactions of 52 insects, including 37 genome-sequenced and 15 transcriptome-sequenced ones. These pathways are available in the iPathDB, which provides searches, web server, data downloads, etc. This database will be highly useful for the insect research community. Database URL: http://ento.njau.edu.cn/ipath/ PMID:25388589

  4. SITE PROGRAM APPLICATIONS ANALYSIS REPORT, INTERNATIONAL WASTE TECHNOLOGIES/GEO CON IN-SITU STABILIZATION/SOLIDIFICATION

    EPA Science Inventory

    An evaluation was performed of the International Waste Technologies (IWT) HWT-20 additive and the Geo-Con, Inc. deep-soil-mixing equipment for an in situ stabilization/solidification process and its applicability as an on-site treatment method for waste site cleanup. emonstration...

  5. TECHNOLOGY EVALUATION REPORT: INTERNATIONAL WASTE TECHNOLOGIES/GEO-CON IN SITU STABILIZATION/SOLIDIFICATION - VOLUME III - UPDATE REPORT

    EPA Science Inventory

    The long-term performance tests provide information on the first follow-up sampling and analysis on the SITE program demonstration of the International Waste Technologies additive, and the Geo-Con deep soil mixing equipment. he samples containing PCBs, were collected one year aft...

  6. TECHNOLOGY EVALUATION REPORT: INTERNATIONAL WASTE TECHNOLOGIES/GEO-CON IN SITU STABILIZATION/SOLIDIFICATION - VOLUME IV - UPDATE REPORT

    EPA Science Inventory

    The long-term performance tests provide information on the first follow-up sampling and analysis on the SITE program demonstration of the International Waste Technologies additive, and the Geo-Con deep soil mixing equipment. he samples containing PCBs, were collected one year aft...

  7. [Teoria della Mente e funzionamento sociale nella schizofrenia: correlazione con anomalie del linguaggio figurato, sintomatologia clinica e intelligenza generale].

    PubMed

    Piovan, Cristiano; Gava, Laura; Campeol, Mara

    2016-01-01

    RIASSUNTO. Scopo. Negli ultimi decenni gli studi hanno mostrato come la Teoria della Mente (ToM) non sia un processo unitario, ma un sistema che include aspetti cognitivi e affettivi. Nell'ambito dei domini che definiscono la social cognition, la ToM rappresenta il miglior predittore dello scarso funzionamento sociale nella schizofrenia. Lo scopo del presente lavoro è stato di esaminare la competenza di un gruppo di pazienti ambulatoriali affetti da schizofrenia in compiti di ToM, di riconoscimento di aspetti metaforici e idiomatici del linguaggio, in una prova di rispetto di regole conversazionali e di indagarne la relazione con il funzionamento sociale. Metodi. Sono stati reclutati 30 pazienti ambulatoriali con diagnosi di schizofrenia e 24 controlli sani. Sono stati somministrati il TIB per il calcolo del QI premorboso, la PANSS, il Theory of Mind Picture Sequencing Task, un test di comprensione di metafore e idiomi e un test conversazionale. Il funzionamento sociale è stato valutato con la PSP. Risultati. Non vi era differenza significativa tra i valori medi del QI premorboso del gruppo dei pazienti e dei controlli. Ai test di ToM e di competenza pragmatica, la differenza tra i gruppi è risultata altamente significativa, con i pazienti che hanno eseguito le prove in modo peggiore. È emersa una correlazione tra la comprensione di metafore e idiomi e le false credenze di secondo ordine. La PSP è risultata correlata con la PANSS e con la quota di ToM cognitiva, ma non con la ToM affettiva. Conclusioni. I risultati hanno mostrato che i soggetti affetti da schizofrenia, in condizione clinica di stabilizzazione, hanno evidenti difficoltà nelle prove di ToM e di comprensione del linguaggio figurato. Nel nostro modello teorico, la correlazione evidenziata tra la ToM cognitiva, i deficit pragmatici, lo stato clinico e il livello di funzionamento sociale suggerisce l'utilità di interventi riabilitativi di recupero delle funzioni metacognitive e delle abilità pragmatiche, al fine di ridurre la disabilità sociale nella schizofrenia. PMID:27030346

  8. A new millimeter-wave observation of the weakly bound CO-N2 complex

    NASA Astrophysics Data System (ADS)

    Surin, L. A.; Potapov, A.; Müller, H. S. P.; Schlemmer, S.

    2015-01-01

    New millimeter-wave transitions of the CO-N2 van der Waals complex have been observed using the intracavity OROTRON jet spectrometer in the frequency range of 103-159 GHz. For the less abundant form, CO-paraN2, a total of 37 rotational transitions were assigned to three K = 0-0, 0-1, 2-1 subbands connecting the (jCO, jN2) = (1, 1) and (jCO, jN2) = (0, 1) internal rotor states. The upper K = 0 and K = 2 "stacks" of rotational levels were probed for the first time here by millimeter-wave spectroscopy following a recent infrared study by Rezaei et al. (2013). The observation of new subbands fixes with higher precision not only these upper K = 0 and K = 2 but also lower K = 1(f) levels, not linked with other stacks in earlier rotational studies. For the more abundant form, CO-orthoN2, five new P-branch rotational transitions of the K = 0-0 "CO bending" subband are reported, thus extending previous measurements. Nuclear quadrupole hyperfine structure due to the presence of two equivalent 14N nuclei was partly resolved and analyzed to give additional information about the angular orientation of the N2 molecule in the complex.

  9. Strains arising by seismic events in the SIRGAS-CON network region

    NASA Astrophysics Data System (ADS)

    Marotta, G. S.; França, G. S.; Monico, J. F. G.; Fuck, R. A.

    2013-03-01

    In this study, we investigate surface strains related to seismic events and their relationship with pre- and post-seismic events in Latin America, by analyzing the variation of estimated earth coordinates supplied by a geodetic network called SIRGAS-CON. Based on data provided by the USGS for the period 2000-2011, and after the Global Congruency test, we selected four events associated with unstable geodetic network points. The resulting strains were estimated based on the finite element method using networks of points considered unstable connected to neighboring points using the Delaunay triangulation. It was possible to determine the strains along with the resulting guidelines for pre- and post-seismic, considering each triangular lattice formed for analysis as a homogeneous solid body. The calculation of strains and verification of the results allowed to analyze the interactions between lithospheric plates from the contraction and extension directions between points located in different plates. Despite the association between seismic events and the strain of geodetic network, some events of magnitude greater than 5.8 Mw were excluded because it does not show (provide) the surface strain, which is located at great depths. It was confirmed that events of greater magnitude provide increased surface strain rate when compared with other similar depths.

  10. Assessing ComSciCon 2013: A science communication workshop for STEM graduate students (Invited)

    NASA Astrophysics Data System (ADS)

    Kohler, S.; Ranjan, S.; Sanders, N.; Morey, S.

    2013-12-01

    We report on the efficacy of Communicating Science 2013, a science communication workshop for graduate students. Effective science communication is imperative for the sharing of scientific ideas, continued funding and support from policy makers, and education of the public. Science graduate students are a prime group to target for communication training, as they will be our future scientists, educators, and EPO professionals. To this end, Communicating Science 2013 (ComSciCon), a workshop organized by and for STEM graduate students, was held in June of this year. This workshop taught graduate students from around the nation to effectively communicate science to both their peers and the public. To learn about grad students' attitudes toward science communication and establish the workshop's efficacy, we surveyed the participants both before and after the workshop. This assessment probed topics such as communication preparation the participants have already received, how science communication is perceived in their home department, and what participants gained from the workshop. We report the results here.

  11. Nonalcoholic Fatty Liver Disease: Pros and Cons of Histologic Systems of Evaluation.

    PubMed

    Brunt, Elizabeth M

    2015-01-01

    The diagnostic phenotype of nonalcoholic fatty liver disease (NAFLD)-in particular, the most significant form in terms of prognosis, nonalcoholic steatohepatitis (NASH)-continues to rely on liver tissue evaluation, in spite of remarkable advances in non-invasive algorithms developed from serum-based tests and imaging-based or sonographically-based tests for fibrosis or liver stiffness. The most common tissue evaluation remains percutaneous liver biopsy; considerations given to the needle size and the location of the biopsy have the potential to yield the most representative tissue for evaluation. The pathologist's efforts are directed to not only global diagnosis, but also assessment of severity of injury. Just as in other forms of chronic liver disease, these assessments can be divided into necroinflammatory activity, and fibrosis with parenchymal remodeling, in order to separately analyze potentially reversible (grade) and non-reversible (stage) lesions. These concepts formed the bases for current methods of evaluating the lesions that collectively comprise the phenotypic spectra of NAFLD. Four extant methods have specific applications; there are pros and cons to each, and this forms the basis of the review. PMID:26771611

  12. Usability of BioCon2 for nucleic acid structures in database.

    PubMed

    Fujii, Satoshi

    2006-01-01

    With the specific three-dimensional structure, DNA/RNA molecules express the specific structural and catalytic functions. The knowledge integration based on three dimensional structures can be used to explain biochemical observations, to predict biological functions and to design drugs specific to a given complex system. In the large RNAs, the helical stems close to each other with specific arrangement. The polymorphic nature of multiple stranded helical structure of nucleic acid relates a promising technique of achieving base sequence specific recognition and hence artificial gene regulation. The database cataloging the interaction motifs of nucleic acid moieties has been developed. Skew matrix, a kind of kink parameter, affords the structural description between the adjacent moieties. The program BioCon2 for estimating these skew matrix and cataloguing for multiple stranded helices has been developed. New version allows for the good properties, i.e., impregnable and flexible presentation of multiple helices. The tentative database including these parameters with the species and physical properties of the surrounding nucleic acid components and amino acids has been constructed. PMID:17150897

  13. Nonalcoholic Fatty Liver Disease: Pros and Cons of Histologic Systems of Evaluation

    PubMed Central

    Brunt, Elizabeth M.

    2016-01-01

    The diagnostic phenotype of nonalcoholic fatty liver disease (NAFLD)—in particular, the most significant form in terms of prognosis, nonalcoholic steatohepatitis (NASH)—continues to rely on liver tissue evaluation, in spite of remarkable advances in non-invasive algorithms developed from serum-based tests and imaging-based or sonographically-based tests for fibrosis or liver stiffness. The most common tissue evaluation remains percutaneous liver biopsy; considerations given to the needle size and the location of the biopsy have the potential to yield the most representative tissue for evaluation. The pathologist’s efforts are directed to not only global diagnosis, but also assessment of severity of injury. Just as in other forms of chronic liver disease, these assessments can be divided into necroinflammatory activity, and fibrosis with parenchymal remodeling, in order to separately analyze potentially reversible (grade) and non-reversible (stage) lesions. These concepts formed the bases for current methods of evaluating the lesions that collectively comprise the phenotypic spectra of NAFLD. Four extant methods have specific applications; there are pros and cons to each, and this forms the basis of the review. PMID:26771611

  14. [Emission spectrum of liquid CO-N2 mixture at shock compression].

    PubMed

    Sun, Yue; Yi, Peng-Fei; Chen, Xian-Meng; Liu, Fu-Sheng; Zhang, Ming-Jian; Zheng, Xue-Ping; Xue, Xue-Dong

    2009-04-01

    Driving a copper projectile to impact a cryo-target made of aluminous alloy at the speed of 2.21 km x s(-1) with a two stage light gas gun, a proper one dimensional shockwave with a speed of 18.76 km x s(-1) was generated and directly acted on a uniform liquid in target, which was condensed by proportional gaseous carbon monoxide and nitrogen. At the measurement of Hugoniots, the full linear spectrum entirely dissociated with the plasma under the shock pressure of 33.5 GPa was caught by the use of intensified charge coupled device and accurate spectrographic technology. From the analysis of the spectrum, the authors know that the transient spectrograph with six channels can be used to measure and record the course of shock compression-irradiancy reliably, and the emitted spectral lines of shock compressed products indicated that the thermal dissociation and phase transition had occurred in homogeneous liquid of CO-N2. Furthermore, comparing the spectral intensity of lower central wavelength with that of higher, the fact of stronger intensity of 488 nm also validates that changes from "optic thin" to "optic thick" exist indeed in dense hydrocarbon liquid acted on by shock pressure. PMID:19626860

  15. Pros and cons of BCG vaccination in countries with low incidence of tuberculosis.

    PubMed

    Tala, E O; Tala-Heikkilä, M M

    1994-07-01

    Preventive bacille Calmette-Guérin (BCG) vaccination, together with case finding and effective chemotherapy, has formed an integral part of the tuberculosis (TB) control program in most countries. In some low-incidence countries the balance of prevention has been more on the side of chemoprophylaxis than of BCG vaccination. The time clearly has come when the strategy of mass BCG vaccination no longer is indicated medically, nor is it cost-effective. The pros and cons of the programs need to be critically evaluated against the present epidemiological background, taking into account the facts that TB, the killer disease, is recovering strength, human immunodeficiency virus infection is on the increase, and multidrug-resistant TB has changed the outcome of this previously fully curable disease. Although no longer appropriate for mass programs, BCG vaccination still should be considered for the protection of selected risk groups in low-incidence countries. The overall efficacy may be of the order 50% to 80%, but the variation is great. Therefore, further research urgently is needed on the effectiveness of BCG as an intervention in local TB programs. PMID:7963444

  16. Pros and cons of liver transplantation in human immunodeficiency virus infected recipients

    PubMed Central

    Baccarani, Umberto; Righi, Elda; Adani, Gian Luigi; Lorenzin, Dario; Pasqualucci, Alberto; Bassetti, Matteo; Risaliti, Andrea

    2014-01-01

    Before the introduction of combined highly active antiretroviral therapy, a positive human immunodeficiency virus (HIV) serological status represented an absolute contraindication for solid organ transplant (SOT). The advent of highly effective combined antiretroviral therapy in 1996 largely contributed to the increased demand for SOT in HIV-positive individuals due to increased patients’ life expectancy associated with the increasing prevalence of end-stage liver disease (ESLD). Nowadays, liver failure represents a frequent cause of mortality in the HIV-infected population mainly due to coinfection with hepatitis viruses sharing the same way of transmission. Thus, liver transplantation (LT) represents a reasonable approach in HIV patients with stable infection and ESLD. Available data presently supports with good evidence the practice of LT in the HIV-positive population. Thus, the issue is no longer “whether it is correct to transplant HIV-infected patients”, but “who are the patients who can be safely transplanted” and “when is the best time to perform LT”. Indeed, the benefits of LT in HIV-infected patients, especially in terms of mid- and long-term patient and graft survivals, are strictly related to the patients’ selection and to the correct timing for transplantation, especially when hepatitis C virus coinfection is present. Aim of this article is to review the pros and cons of LT in the cohort of HIV infected recipients. PMID:24833865

  17. Prevalencia y tamizaje del Trastorno por Déficit de Atención con Hiperactividad en Costa Rica

    PubMed Central

    Weiss, Nicholas T.; Schuler, Jovita; Monge, Silvia; McGough, James J.; Chavira, Denise; Bagnarello, Monica; Herrera, Luis Diego; Mathews, Carol A.

    2015-01-01

    Resumen La investigación tuvo como propósito estimar la prevalencia del Trastorno por Déficit de Atención con Hiperactividad (TDAH) en Costa Rica y determinar si la versión en español del cuestionario Swanson Nolan and Pelham Scale IV (SNAP-IV) es un instrumento de tamizaje útil en una población de niños y niñas escolares costarricenses. El instrumento fue entregado a padres y maestros de 425 niños entre 5 y 13 años de edad (promedio = 8.8). Todos fueron evaluados con el instrumento Swanson, Kotkin, Agler, M-Flynn and Pelham Scale (SKAMP). Su diagnóstico fue confirmado con una entrevista clínica. La sensibilidad y la especificidad del SNAP-IV fueron evaluadas como predictores de criterios de diagnóstico según el DSM-IV. La prevalencia puntual en la muestra del TDAH fue del 5%. El tamizaje más preciso lo hizo el SNAP-IV completado por el maestro en un corte de 20%, con una sensibilidad de 96% y una especificidad de un 82%. La sensibilidad de los instrumentos completados por los padres fue más baja que aquella de los maestros. El SNAP-IV completado por las maestras con un corte aislando el 20% de los mayores puntajes categorizó correctamente a un 87% de los sujetos. PMID:22432094

  18. Añadir quimioterapia después de la radioterapia mejora la supervivencia de adultos con un tipo de tu

    Cancer.gov

    Adultos con gliomas de grado bajo, una forma de tumor cerebral, que recibieron tratamiento con quimioterapia después de la radioterapia vivieron más tiempo que pacientes que recibieron solo radioterapia, según los resultados de seguimiento a largo plazo d

  19. 40 CFR 180.1213 - Coniothyrium minitans strain CON/M/91-08; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Coniothyrium minitans strain CON/M/91... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1213 Coniothyrium minitans strain CON/M... tolerance is established for residues of the microbial pesticide Coniothyrium minitans strain...

  20. 40 CFR 180.1213 - Coniothyrium minitans strain CON/M/91-08; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Coniothyrium minitans strain CON/M/91... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1213 Coniothyrium minitans strain CON/M... tolerance is established for residues of the microbial pesticide Coniothyrium minitans strain...

  1. 40 CFR 180.1213 - Coniothyrium minitans strain CON/M/91-08; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Coniothyrium minitans strain CON/M/91... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1213 Coniothyrium minitans strain CON/M... tolerance is established for residues of the microbial pesticide Coniothyrium minitans strain...

  2. 40 CFR 180.1213 - Coniothyrium minitans strain CON/M/91-08; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Coniothyrium minitans strain CON/M/91... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1213 Coniothyrium minitans strain CON/M... tolerance is established for residues of the microbial pesticide Coniothyrium minitans strain...

  3. Outreach Opportunities for Early Career Scientists at the Phoenix ComiCon

    NASA Astrophysics Data System (ADS)

    Horodyskyj, L.; Walker, S. I.; Forrester, J. H.

    2014-12-01

    The Phoenix ComiCon (PCC) is a rapidly growing annual four-day pop culture event, featuring guests, costuming, exhibits, and discussion panels for popular sci-fi, fantasy, horror, and anime franchises. In 2013, PCC began experimenting with science discussion panels. The popularity of the science programming resulted in an expansion of the track for 2014, which Horodyskyj was responsible for coordinating. Thirty hours of programming were scheduled, including 25 discussion panels, NASA's FameLab, and a Mars room. Panelists included industry specialists, established scientists, STEM outreach enthusiasts, and early career scientists. The majority of the panelists were early career scientists recruited from planetary sciences and biology departments at ASU and UA. Panel topics included cosmology, biotechnology, artificial intelligence, space exploration, astrobiology, and the cross-linkages of each with pop culture. Formats consisted of Q&A, presentations, and interactive game shows. Although most panels were aimed at the general audience, some panels were more specialized. PCC 2014 attracted 77,818 attendees. The science programming received rave reviews from the audience, the PCC management, and the panelists themselves. Many panel rooms were filled to capacity and required crowd control to limit attendance. We observed the formation of science "groupies" who sought out the science panels exclusively and requested more information on other science public events in the Phoenix area. We distributed surveys to several select sessions to evaluate audience reasons for attending the science panels and their opinion of the scientists they observed. We will present the results of these surveys. As the PCC continues to grow at an exponential rate, the science programming will continue to expand. We will discuss ideas for continued expansion of the PCC science programming both to serve the public and as a unique public outreach opportunity for early career scientists.

  4. Strain Rate by Geodetic Observations Associated with Seismic Events in the SIRGAS-CON Network Region.

    NASA Astrophysics Data System (ADS)

    Marotta, G. S.; Franca, G.; Galera Monico, J. F.; Fuck, R. A.

    2014-12-01

    This research investigates surface strains related to seismic events and their relationship with pre- and post-seismic events in South American, Antarctica, Nazca, Cocos, North American and Caribbean plates , by analyzing the variation of estimated earth coordinates, for the period 2000-2014, supplied by a geodetic network called SIRGAS-CON. Based on data provided by the USGS for the same period, and after the Global Congruency test, we selected the events associated with unstable geodetic network points. The resulting strains were estimated based on the finite element method. It was possible to determine the strains along with the resulting guidelines for pre- and post-seismic, considering each region formed for analysis as a homogeneous solid body. Later, a multi-year solution of the network was estimated and used to estimate the strain rates of the earth surface from the changing directions of the velocity vectors of 332 geodetic points located in the South American plate and surround plates. The strain rate was determined and, using Euler vector computed, it was possible to estimate the convergence and accommodation rates to each plate. The results showed that contraction regions coincide with locations with most of the high magnitude seismic events. It suggest that major movements detected on the surface occur in regions with more heterogeneous geological structures and multiple rupture events; significant amounts of elastic strain can be accumulated on geological structures away from the plate boundary faults; and, behavior of contractions and extensions is similar to what has been found in seismological studies. Despite the association between seismic events and the strain of geodetic network, some events of high magnitude were excluded because it does not show the surface strain, which is located at great depths. It was confirmed that events of greater magnitude provide increased surface strain rate when compared with other similar depths.

  5. Estereotipos Sexuales y su Relación con Conductas Sexuales Riesgosas1,2,3

    PubMed Central

    Pérez-Jiménez, David; Orengo-Aguayo, Rosaura E.

    2012-01-01

    Resumen Los estereotipos sexuales son creencias generalmente aceptadas y poco cuestionadas que podrían contribuir a cómo los hombres y las mujeres debemos expresar nuestra sexualidad. Los objetivos de este estudio eran identificar cuántos hombres y mujeres heterosexuales en Puerto Rico endosaban ciertos estereotipos acerca de la sexualidad masculina y femenina y explorar la relación entre el endoso de estos estereotipos sexuales y las actitudes hacia el condón masculino y su uso en relaciones sexuales vaginales Llevamos a cabo un estudio descriptivo-correlacional mediante el cual le administramos dos escalas, una sobre sexualidad masculina y otra sobre sexualidad femenina a un grupo de 429 personas heterosexuales. Encontramos que los hombres endosaron estereotipos sexuales masculinos y femeninos más que las mujeres y que estos tienden a tener una visión más conservadora respecto a la sexualidad femenina que la que tienen sobre su propia sexualidad. Las mujeres, por otra parte, tienden a ver su propia sexualidad y la sexualidad masculina en términos menos estereotipados y más equitativos. También encontramos que a mayor endoso de creencias tradicionales sobre la sexualidad masculina y femenina, peor la actitud hacia el uso del condón masculino. Sin embargo, el endosar estereotipos sexuales masculinos y/o femeninos no se relacionó con el uso del condón. Estos hallazgos contradicen la literatura que sugiere que estos estereotipos sexuales y de género resultan en conductas sexuales de alto riesgo, lo cual tiene implicaciones importantes para el desarrollo e implementación de programas de prevención. PMID:24575164

  6. 40Ar/39Ar laserprobe study of the Day Nui Con Voi Metamorphic Complex, Vietnam

    NASA Astrophysics Data System (ADS)

    Wu, C.; Lo, C.; Yeh, M.; Chung, S.; Lee, T.

    2009-12-01

    The garnet bearing gneiss within the Day Nui Con Voi (DNCV) Metamorphic Complex along the Red River Shear Zone (RRSZ) in North Vietnam, recorded a long tectonothermal history since the Indosinian orogeny. In-situ 40Ar/39Ar laserprobe study of biotite inclusions within garnet porphyroblasts and matrix biotites, combining with microstructural and scanning electron microscopy (SEM) studies, deciphered the timing and duration of thermal events. Biotites from two matrix fabrics from different deformation events show approximately similar 40Ar/39Ar age ranges in 19-24Ma, depending grain size. These matrix biotite ages are best interpreted to record a rapid cooling event associating with the left-lateral shearing event of the RRSZ. Whereas, all biotite inclusions exhibit age zoning patterns with 40Ar/39Ar ages gradually increase from 17 Ma to more than 28 Ma according to their diffusion pathways. These age variations may have resultant from a combination effect of argon retention by garnet shielding, which provides a best recorder to the metamorphic event, and argon diffusion loss along the deformed cracks during the shearing event of the RRSZ. Diffusion modeling of these age zoning indicated that the total duration of argon diffusion loss may have lasted for nearly 9 Myr and argon diffusion may have occurred sometime around 24.5Ma. These results are generally in good agreement with previous interpretation, but provide better resolution of 40Ar/39Ar age data for deciphering the history of thermal event in the DNCV Metamorphic Complex and the left-lateral shearing event of the RRSZ in Vietnam, as well.

  7. Strain Rate into South American Plate by SIRGAS-CON Geodetic Observations

    NASA Astrophysics Data System (ADS)

    Marotta, G. S.; Franca, G. S.; Monico, J. G.; Fuck, R. A.

    2013-05-01

    In this study were investigated the surface strain rates computed from the direction variations and velocity values estimated from the coordinates of the continuous monitoring geodetic network called SIRGAS-CON. That investigation was done using points located in the South American plate. The determination of the strain rate was based on the Finite Element method using points defined by Delaunay triangulation (sub-networks). Each one of sub-networks was considered as an homogeneous solid body. Using these methods was possible to separate the strain from the plate movement. The results showed that there are differences of strain rate along the South American plate. From the results were suggest that near to the west board of the plate, the strain is more significant, as expected, because this region is near to one area where Nazca Plate subduct South American Plate. It was detected that the contraction region founded in this area coincides whit the region where occurs most of earthquakes of greater magnitude. Far from the board, there are some areas with anomalies of significant strain of extension and contraction that can be originated by differences of stress aligned with different geological composites. By the results, It may be concluded that large surface movements occur in regions with more heterogeneous geological structures and multiple event of rupture, that large earthquakes arising from large tectonic activity into South American Plate are concentrated in areas with contraction strain rates predominantly oriented towards northeast-southwest, that significant amounts of elastic strain can be accumulated over geological structures away from fault plate boundary and that the behavior of contractions and extensions are similar to that found by different researches involving geophysical studies. Dilation and principal components of strain rate

  8. Strain rate of the South American lithospheric plate by SIRGAS-CON geodetic observations

    NASA Astrophysics Data System (ADS)

    Marotta, Giuliano Sant'Anna; França, George Sand; Galera Monico, João Francisco; Fuck, Reinhardt Adolfo; Oswaldo de Araújo Filho, José

    2013-11-01

    A multiyear solution of the SIRGAS-CON network was used to estimate the strain rates of the earth surface from the changing directions of the velocity vectors of 140 geodetic points located in the South American plate. The strain rate was determined by the finite element method using Delaunay triangulation points that formed sub-networks; each sub-network was considered a solid and homogeneous body. The results showed that strain rates vary along the South American plate and are more significant on the western portion of the plate, as expected, since this region is close to the subduction zone of the Nazca plate beneath the South American plate. After using Euler vectors to infer Nazca plate movement and to orient the velocity vectors of the South American plate, it was possible to estimate the convergence and accommodation rates of the Nazca and South American plates, respectively. Strain rate estimates permitted determination of predominant contraction and/or extension regions and to establish that contraction regions coincide with locations with most of the high magnitude seismic events. Some areas with extension and contraction strains were found to the east within the stable South American plate, which may result from different stresses associated with different geological characteristics. These results suggest that major movements detected on the surface near the Nazca plate occur in regions with more heterogeneous geological structures and multiple rupture events. Most seismic events in the South American plate are concentrated in areas with predominant contraction strain rates oriented northeast-southwest; significant amounts of elastic strain can be accumulated on geological structures away from the plate boundary faults; and, behavior of contractions and extensions is similar to what has been found in seismological studies.

  9. Do Patient-perceived Pros and Cons of Opioids Predict Sustained Higher-Dose Use?

    PubMed Central

    Thielke, Stephen M.; Turner, Judith A.; Shortreed, Susan M.; Saunders, Kathleen; LeResche, Linda; Campbell, Cynthia I.; Weisner, Constance C.; Korff, Michael V.

    2013-01-01

    Objectives Chronic opioid therapy (COT) is associated with various adverse outcomes, especially at higher doses, yet little is known about predictors of sustained higher-dose COT. This study aimed to ascertain, among higher-dose COT patients, the association of patient-perceived pros and cons of opioids with continued higher-dose use 1 year later. Methods Patients (N = 1229) in 2 large health plans prescribed ? 50 mg morphine-equivalent dose (MED) per day for chronic non-cancer pain completed a survey assessing opioid benefits and harms. The Prescribed Opioid Difficulties Scale questionnaire assessed psychosocial problems, concerns, benefits, and side effects related to opioid use. Logistic regression models estimated the associations of the reported benefits and problems with higher-dose continuation (? 50 mg MED/d) versus dose reduction (< 50 mg MED/d) 1 year later. Results Over 80% of participants continued higher-dose opioid use at 1 year, regardless of reported problems, concerns, side effects, pain reduction, or perceived helpfulness. Higher scores on the Prescribed Opioid Difficulties Scale Problems subscale (odds ratio = 0.79, 95% confidence interval, 0.68–0.92) and Concerns subscale (odds ratio = 0.76, 95% confidence interval, 0.65–0.90) were negatively associated with higher-dose use 1 year later. Other baseline measures (opioid helpfulness, reduction in pain, number of side effects, and side effect bothersomeness) were not significantly associated with continued higher-dose use. Discussion The large majority of patients continued using higher-dose opioids regardless of baseline characteristics. These findings suggest the difficulty of reducing opioid dose among chronic higher-dose opioid users. PMID:23535150

  10. Characterization Data Package for Containerized Sludge Samples Collected from Engineered Container SCS-CON-210

    SciTech Connect

    Fountain, Matthew S.; Fiskum, Sandra K.; Baldwin, David L.; Daniel, Richard C.; Bos, Stanley J.; Burns, Carolyn A.; Carlson, Clark D.; Coffey, Deborah S.; Delegard, Calvin H.; Edwards, Matthew K.; Greenwood, Lawrence R.; Neiner, Doinita; Oliver, Brian M.; Pool, Karl N.; Schmidt, Andrew J.; Shimskey, Rick W.; Sinkov, Sergey I.; Snow, Lanee A.; Soderquist, Chuck Z.; Thompson, Christopher J.; Trang-Le, Truc LT; Urie, Michael W.

    2013-09-10

    This data package contains the K Basin sludge characterization results obtained by Pacific Northwest National Laboratory during processing and analysis of four sludge core samples collected from Engineered Container SCS-CON-210 in 2010 as requested by CH2M Hill Plateau Remediation Company. Sample processing requirements, analytes of interest, detection limits, and quality control sample requirements are defined in the KBC-33786, Rev. 2. The core processing scope included reconstitution of a sludge core sample distributed among four to six 4-L polypropylene bottles into a single container. The reconstituted core sample was then mixed and subsampled to support a variety of characterization activities. Additional core sludge subsamples were combined to prepare a container composite. The container composite was fractionated by wet sieving through a 2,000 micron mesh and a 500-micron mesh sieve. Each sieve fraction was sampled to support a suite of analyses. The core composite analysis scope included density determination, radioisotope analysis, and metals analysis, including the Waste Isolation Pilot Plant Hazardous Waste Facility Permit metals (with the exception of mercury). The container composite analysis included most of the core composite analysis scope plus particle size distribution, particle density, rheology, and crystalline phase identification. A summary of the received samples, core sample reconstitution and subsampling activities, container composite preparation and subsampling activities, physical properties, and analytical results are presented. Supporting data and documentation are provided in the appendices. There were no cases of sample or data loss and all of the available samples and data are reported as required by the Quality Assurance Project Plan/Sampling and Analysis Plan.

  11. (Con)text-specific effects of visual dysfunction on reading in posterior cortical atrophy

    PubMed Central

    Yong, Keir X.X.; Shakespeare, Timothy J.; Cash, Dave; Henley, Susie M.D.; Warren, Jason D.; Crutch, Sebastian J.

    2014-01-01

    Reading deficits are a common early feature of the degenerative syndrome posterior cortical atrophy (PCA) but are poorly understood even at the single word level. The current study evaluated the reading accuracy and speed of 26 PCA patients, 17 typical Alzheimer's disease (tAD) patients and 14 healthy controls on a corpus of 192 single words in which the following perceptual properties were manipulated systematically: inter-letter spacing, font size, length, font type, case and confusability. PCA reading was significantly less accurate and slower than tAD patients and controls, with performance significantly adversely affected by increased letter spacing, size, length and font (cursive < non-cursive), and characterised by visual errors (69% of all error responses). By contrast, tAD and control accuracy rates were at or near ceiling, letter spacing was the only perceptual factor to influence reading speed in the same direction as controls, and, in contrast to PCA patients, control reading was faster for larger font sizes. The inverse size effect in PCA (less accurate reading of large than small font size print) was associated with lower grey matter volume in the right superior parietal lobule. Reading accuracy was associated with impairments of early visual (especially crowding), visuoperceptual and visuospatial processes. However, these deficits were not causally related to a universal impairment of reading as some patients showed preserved reading for small, unspaced words despite grave visual deficits. Rather, the impact of specific types of visual dysfunction on reading was found to be (con)text specific, being particularly evident for large, spaced, lengthy words. These findings improve the characterisation of dyslexia in PCA, shed light on the causative and associative factors, and provide clear direction for the development of reading aids and strategies to maximise and sustain reading ability in the early stages of disease. PMID:24841985

  12. (Con)text-specific effects of visual dysfunction on reading in posterior cortical atrophy.

    PubMed

    Yong, Keir X X; Shakespeare, Timothy J; Cash, Dave; Henley, Susie M D; Warren, Jason D; Crutch, Sebastian J

    2014-08-01

    Reading deficits are a common early feature of the degenerative syndrome posterior cortical atrophy (PCA) but are poorly understood even at the single word level. The current study evaluated the reading accuracy and speed of 26 PCA patients, 17 typical Alzheimer's disease (tAD) patients and 14 healthy controls on a corpus of 192 single words in which the following perceptual properties were manipulated systematically: inter-letter spacing, font size, length, font type, case and confusability. PCA reading was significantly less accurate and slower than tAD patients and controls, with performance significantly adversely affected by increased letter spacing, size, length and font (cursive < non-cursive), and characterised by visual errors (69% of all error responses). By contrast, tAD and control accuracy rates were at or near ceiling, letter spacing was the only perceptual factor to influence reading speed in the same direction as controls, and, in contrast to PCA patients, control reading was faster for larger font sizes. The inverse size effect in PCA (less accurate reading of large than small font size print) was associated with lower grey matter volume in the right superior parietal lobule. Reading accuracy was associated with impairments of early visual (especially crowding), visuoperceptual and visuospatial processes. However, these deficits were not causally related to a universal impairment of reading as some patients showed preserved reading for small, unspaced words despite grave visual deficits. Rather, the impact of specific types of visual dysfunction on reading was found to be (con)text specific, being particularly evident for large, spaced, lengthy words. These findings improve the characterisation of dyslexia in PCA, shed light on the causative and associative factors, and provide clear direction for the development of reading aids and strategies to maximise and sustain reading ability in the early stages of disease. PMID:24841985

  13. Iliac crest autograft versus alternative constructs for anterior cervical spine surgery: Pros, cons, and costs

    PubMed Central

    Epstein, Nancy E.

    2012-01-01

    Background: Grafting choices available for performing anterior cervical diskectomy/fusion (ACDF) procedures have become a major concern for spinal surgeons, and their institutions. The “gold standard”, iliac crest autograft, may still be the best and least expensive grafting option; it deserves to be reassessed along with the pros, cons, and costs for alternative grafts/spacers. Methods: Although single or multilevel ACDF have utilized iliac crest autograft for decades, the implant industry now offers multiple alternative grafting and spacer devices; (allografts, cages, polyether-etherketone (PEEK) amongst others). While most studies have focused on fusion rates and clinical outcomes following ACDF, few have analyzed the “value-added” of these various constructs (e.g. safety/efficacy, risks/complications, costs). Results: The majority of studies document 95%-100% fusion rates when iliac crest autograft is utilized to perform single level ACDF (X-ray or CT confirmed at 6-12 postoperative months). Although many allograft studies similarly quote 90%-100% fusion rates (X-ray alone confirmed at 6-12 postoperative months), a recent “post hoc analysis of data from a prospective multicenter trial” (Riew KD et. al., CSRS Abstract Dec. 2011; unpublished) revealed a much higher delayed fusion rate using allografts at one year 55.7%, 2 years 87%, and four years 92%. Conclusion: Iliac crest autograft utilized for single or multilevel ACDF is associated with the highest fusion, lowest complication rates, and significantly lower costs compared with allograft, cages, PEEK, or other grafts. As spinal surgeons and institutions become more cost conscious, we will have to account for the “value added” of these increasingly expensive graft constructs. PMID:22905321

  14. Quantum analytical modeling and simulation of CNT on insulator (COI) and CNT on nothing (CON) FET: a comparative analysis

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sudipta; Bandyopadhyay, Dipan; Dutta, Pranab Kishore; Sarkar, Subir Kumar

    2016-01-01

    A comprehensive performance analysis by quantum analytical modeling of CNT on insulator (COI) and CNT on nothing (CON) FET having channel length 20 nm has been proposed and investigated on the basis of 2D Poisson's Equation and solution of 1-D Schrodinger's Equation and validated using ATLAS 2D simulator. As classical approximations fail to describe carrier quantization, charge inversion and potential profile of a device at sub-100 nm regime, here for the first time an analytical model in quantum mechanical aspect for COI/CON devices has been derived. Effects of high-k dielectrics in place of conventional SiO2 over the device characteristics have been thoroughly discussed. Moreover, all noticeable benefits of our device to the so called SOI/SON architecture have also been vividly justified.

  15. GP73 was upregulated in PBMC stimulated with ConA but failed to promote lymphocyte proliferation.

    PubMed

    Wang, Fang; Li, Zhaotao; Li, Leike; Hu, Longbo; Xiao, Jing; Su, Zhong; Peng, Tao

    2015-03-01

    Golgi protein 73-kD (GP73), a type II Golgi transmembrane glycoprotein, is highly expressed in a variety of human diseases, but its physiology and pathology remain unknown. In examining the function of GP73 in the immune system, treatment of human PBMC with ConA significantly increased the intracellular expression of GP73 and its secretion into the culture medium. Two-way MLR and the ConA stimulation assay showed that treatment with purified GP73 protein barely affected the proliferation of PBMC. These results suggest that lymphocyte-secreted GP73 might partially contribute to higher serum GP73 in patients, and secreted GP73 exerts an extremely weak effect on the proliferation of PBMC ex vivo. PMID:25231014

  16. Atomic Mechanism of Electrocatalytically Active Co-N Complexes in Graphene Basal Plane for Oxygen Reduction Reaction.

    PubMed

    Li, Feng; Shu, Haibo; Hu, Chenli; Shi, Zhaoyi; Liu, Xintong; Liang, Pei; Chen, Xiaoshuang

    2015-12-16

    Superior catalytic activity and high chemical stability of inexpensive electrocatalysts for the oxygen reduction reaction (ORR) are crucial to the large-scale practical application of fuel cells. The nonprecious metal/N modified graphene electrocatalysts are regarded as one of potential candidates, and the further enhancement of their catalytic activity depends on improving active reaction sites at not only graphene edges but also its basal plane. Herein, the ORR mechanism and reaction pathways of Co-N co-doping onto the graphene basal plane have been studied by using first-principles calculations and ab initio molecular dynamics simulations. Compared to singly N-doped and Co-doped graphenes, the Co-N co-doped graphene surface exhibits superior ORR activity and the selectivity toward a four-electron reduction pathway. The result originates from catalytic sites of the graphene surface being modified by the hybridization between Co 3d states and N 2p states, resulting in the catalyst with a moderate binding ability to oxygenated intermediates. Hence, introducing the Co-N4 complex onto the graphene basal plane facilitates the activation of O2 dissociation and the desorption of H2O during the ORR, which is responsible for the electrocatalyst with a smaller ORR overpotential (?1.0 eV) that is lower than that of Co-doped graphene by 0.93 eV. Our results suggest that the Co-N co-doped graphene is able to compete against platinum-based electrocatalysts, and the greater efficient electrocatalysts can be realized by carefully optimizing the coupling between transition metal and nonmetallic dopants in the graphene basal plane. PMID:26566009

  17. Water as an economic good and water tariff design. Comparison between IBT-con and IRT-cap

    NASA Astrophysics Data System (ADS)

    Liu, Junguo; Savenije, Hubert H. G.; Xu, Jianxin

    Although the proclamation of “water as an economic good” has been generally accepted among water resources managers, there are still some debates on the explanation of this topic. In this paper it is argued that different water forms or uses have different kinds of economic value. Even for the same form or use, water economic value can be transferred from one kind to another by interventions. If water is an economic good, water pricing should be recognized as one of the important incentive measures for water demand management. Although the increased block tariffs (IBTs) have become the tariff structure of choice in many developing countries, it still deserves more careful examination. The traditional IBT-con cannot achieve the initial objectives of IBTs for its incorrect designed structure. This paper is intent to critically examine the use of IBT-con and to strongly promote a new tariff structure, IRT-cap. The case study of Weinan City shows that IRT-cap is an effective tariff to achieve the objectives of equity, simplicity, transparency and implement as well. Also IRT-cap seems easier to achieve cost recovery than the traditional IBT-con taking the ability to pay of water consumers into account. Pilot projects are necessary to be formulated for verification of this new tariff.

  18. CHILES Con Pol: Probing galaxy evolution, the dark Universe, and cosmic magnetism with a deep 1000 hour Jansky VLA survey

    NASA Astrophysics Data System (ADS)

    Hales, Christopher A.; Chiles Con Pol Collaboration

    2014-04-01

    We recently started a 1000 hour campaign to observe 0.2 square degrees of the COSMOS field in full polarization continuum at 1.4 GHz with the Jansky VLA, as part of a joint program with the spectral line COSMOS HI Large Extragalactic Survey (CHILES). When complete, we expect our CHILES Continuum Polarization (CHILES Con Pol) survey to reach an unprecedented SKA-era sensitivity of 0.7 uJy per 4 arcsecond FWHM beam. Here we present the key goals of CHILES Con Pol, which are to (i) produce a source catalog of legacy value to the astronomical community, (ii) measure differential source counts in total intensity, linear polarization, and circular polarization in order to constrain the redshift and luminosity distributions of source populations, (iii) perform a novel weak lensing study using radio polarization as an indicator of intrinsic alignment to better study dark energy and dark matter, and (iv) probe the unknown origin of cosmic magnetism by measuring the strength and structure of intergalactic magnetic fields in the filaments of large scale structure. The CHILES Con Pol source catalog will be a useful resource for upcoming wide-field surveys by acting as a training set for machine learning algorithms, which can then be used to identify and classify radio sources in regions lacking deep multiwavelength coverage.

  19. Integrated Concentration in Science (iCons): Undergraduate Education Through Interdisciplinary, Team-Based, Real-World Problem Solving

    NASA Astrophysics Data System (ADS)

    Tuominen, Mark

    2013-03-01

    Attitude, Skills, Knowledge (ASK) - In this order, these are fundamental characteristics of scientific innovators. Through first-hand practice in using science to unpack and solve complex real-world problems, students can become self-motivated scientific leaders. This presentation describes the pedagogy of a recently developed interdisciplinary undergraduate science education program at the University of Massachusetts Amherst focused on addressing global challenges with scientific solutions. Integrated Concentration in Science (iCons) is an overarching concentration program that supplements the curricula provided within each student's chosen major. iCons is a platform for students to perform student-led research in interdisciplinary collaborative teams. With a schedule of one course per year over four years, the cohort of students move through case studies, analysis of real-world problems, development of potential solutions, integrative communication, laboratory practice, and capstone research projects. In this presentation, a track emphasizing renewable energy science is used to illustrate the iCons pedagogical methods. This includes discussion of a third-year laboratory course in renewable energy that is educationally scaffolded: beginning with a boot camp in laboratory techniques and culminating with student-designed research projects. Among other objectives, this course emphasizes the practice of using reflection and redesign, as a means of generating better solutions and embedding learning for the long term. This work is supported in part by NSF grant DUE-1140805.

  20. Deformation sequences of the Day Nui Con Voi metamorphic belt, northern Vietnam

    NASA Astrophysics Data System (ADS)

    Yeh, M. W.; Lee, T. Y.; Lo, C. H.; Chung, S. L.; Lan, C. Y.; Lee, J. C.; Lin, T. S.; Lin, Y. J.

    2003-04-01

    The correlation of structure, microstructure and metamorphic assemblages is of fundamental importance to the understanding of the complex tectonic history and kinematics of the Day Nui Con Voi (DNCV) metamorphic belt in Vietnam along the Ailao Shan-Red River (ASRR) shear zone as it provides constraints on the relative timing of the deformation, kinematics and metamorphism. High-grade metamorphic rocks of amphibolite faces showed consistent deformation sequences of three folding events followed by one brittle deformation through all four cross sections from Lao Cai to Viet Tri indicated the DNCV belt experienced similar deformation condition throughout its length. The first deformation event, D1, produced up-right folds (locally preserved) with sub-vertical, NE-SW striking axial planes with dextral sense of shear probably formed during the early phase of the lowermost Triassic Indosinian orogeny. Followed by this compressional event is a gravitational collapsing event, D2, which is the major deformation and metamorphic event characterized by kyanite grade metamorphism and large scale horizontal folds with NW-SE (320) striking sub-horizontal axial pane showing sinsistral sense of shear most likely formed during the Oligocene-Miocene SE extrusion of Indochina peninsula. The 3rd folding event, D3, is a post-metamorphism doming event with NW-SE (310) striking sub-vertical axial plane that folded/tilted the once sub-horizontal D2 axial planes into shallowly (<30 degrees) NE dipping on the NE limb, and SW dipping on the SW limb possibly due to left-lateral movement of the N-S trending Xian Shui He fault system in Mid-Miocene. The outward decreasing of the metamorphic grade from kyanite to garnet then biotite indicated the D3 occurred post metamorphism. Reactivation of the sub-horizontal D2 fold axial planes showed dextral sense of shear possibly due to Late Miocene-Pliocene right-lateral movement of the ASRR shear zone. This right lateral movement continuously deformed the DNCV with brittle fractures such as joints and normal faults (D4) striking NE-SW to E-W and NW-SE.

  1. Cálculos ab initio con correlación electrónica

    NASA Astrophysics Data System (ADS)

    Merchán Bonete, M.

    Estamos entrando en una era donde la ortogonalidad entre las investigaciones de carácter experimental y de naturaleza teórica se irá difuminando progresivamente y la problemática a resolver quedará en escena como el único actor principal de la obra. Como premisa para una cooperación teórico-experimental de igual a igual, la metodología químico-cuántica utilizada debe ser capaz de ofrecer resultados de carácter predictivo. Sin duda, esta madurez en la metodología químico-cuántica ya la hemos alcanzado hace algunos años, tal y como muestra entre otras muchas, la labor que nuestro grupo ha realizado en el transcurso de la última década, dentro del campo de la Espectroscopía Teórica. Los estudios realizados comprenden una amplia gama de sistemas, variando tanto en tamaño como en complejidad, abordando problemáticas espectroscópicas consideradas tradicionalmente como especialmente controvertidas. Nuestra contribución científica más relevante reside en el carácter cuantitativo de las asignaciones espectroscópicas que hemos propuesto en base a resultados ab initio. Recordemos que en los años noventa los resultados ab initio solían presentar para las energías de excitación de sistemas de tamaño molecular moderado, como el benceno, errores de más de 1 eV. En comparación con el éxito relativo de los métodos semiempíricos, la frustración de la metodología ab initio quedaba todavía más patente. Los estudios que hemos presentado representan una comprensión profunda de los espectros electrónicos en sistemas orgánicos claves, mostrando el camino a seguir para obtener asignaciones espectroscópicas precisas (entre 0.1-0.2 eV). La naturaleza del método CASPT2 junto al diseño de estrategias computacionales nos ha permitido alcanzar el carácter cuantitativo con el que se caracterizan nuestras contribuciones[1,2]. Por todo ello, algunos de los trabajos publicados se consideran clásicos dentro del campo, pues en cierto modo definen el campo, y se reflejan en libros publicados recientemente. En la conferencia se analizarán ciertos pormenores de las investigaciones realizadas. El tipo de aplicaciones llevadas a cabo hasta la fecha se ilustrará mediante el estudio teórico del espectro electrónico de ciclooctatetraeno. Dando un paso más en la evolución de nuestra investigación, pretendemos en la actualidad describir, desde un formalismo teórico y al mismo nivel de exigencia, los mecanismos subyacentes que tienen lugar en las reacciones biológicas fototoinducidas, es decir, reacciones que se inician mediante la absorción de luz[3]. Como muestra de la caracterización de los procesos fotofísicos y fotoquímicos en fotobiología teórica, hemos elegido la descripción de la conversión interna ultrarrápida que tiene lugar en los cromóforos del ADN. Los estados excitados de las moléculas de los ácidos nucleicos presentan tiempos de vida media que se encuentran en el rango de sub-picosegundos, sugiriendo la presencia de un canal ultrarrápido de conversión interna, lo que normalmente se asocia en la fotoquímica contemporánea a una intersección cónica entre el estado excitado y el fundamental[4]. De esta forma nuestro ADN previene de forma eficaz posibles reacciones en el estado excitado y se revela como un excelente protector solar.

  2. Fuentes de variabilidad en el diagnóstico de gastritis atrófica multifocal asociada con la infección por Helicobacter pylori1

    PubMed Central

    Bravo, Luis Eduardo; Bravo, Juan Carlos; Realpe, José Luis; Zarama, Guillermo; Piazuelo, MarÍa Blanca; Correa, Pelayo

    2014-01-01

    RESUMEN Introducción El mapeo de las diferentes regiones del estómago y el número de fragmentos de mucosa gástrica disponibles para evaluación histopatológica son fuentes importantes de variación en el momento de clasificar y hacer la gradación de la gastritis crónica. Objetivos Estimar la sensibilidad del número de fragmentos de mucosa gástrica necesarios para establecer los diagnósticos de gastritis atrófica con metaplasia intestinal (MI), displasia y estado de infección por Helicobacter pylori. Además evaluar la variabilidad intra-observador en la clasificación de estas lesiones precursoras del cáncer gástrico. Materiales y métodos En una cohorte de 6 años de seguimiento se evaluaron 1,958 procedimientos de endoscopia realizados por dos gastroenterólogos. En cada procedimiento y de cada participante se obtuvieron 5 biopsias de mucosa gástrica que representaban antro, incisura angularis y cuerpo. Un único patólogo hizo la interpretación histológica de las 5 biopsias y proporcionó un diagnóstico definitivo global que se utilizó como patrón de referencia. Cada fragmento de mucosa gástrica examinado condujo a un diagnóstico individual para cada biopsia que se comparó con el patrón de referencia. La variabilidad intra-observador se evaluó en 127 personas que corresponden a una muestra aleatoria de 20% del total de endoscopias hechas a los 72 meses de seguimiento. Resultados La sensibilidad del diagnóstico de MI y displasia gástrica aumentó de manera significativa con el número de fragmentos de mucosa gástrica evaluados El sitio anatómico de mayor sensibilidad para el diagnóstico de MI y displasia fue la incisura angularis. Para descubrir H. pylori se logró alta sensibilidad con el estudio de un solo fragmento de mucosa gástrica (95.9%) y fue independiente del sitio de obtención de la biopsia. El acuerdo intra-observador para el diagnóstico de gastritis crónica fue 86.1% con valor kappa de 0.79 IC 95% (0.76-0.85). Las biopsias fijadas en alcohol fueron inadecuadas para demostrar H. pylori e interpretar los cambios de displasia. Conclusión El número de fragmentos de mucosa gástrica evaluados, el método de fijación y la región del estómago donde se obtienen las biopsias son factores muy importantes para lograr una correcta clasificación de la gastritis crónica atrófica multifocal. PMID:25267864

  3. The transcription factor Con7p is a central regulator of infection-related morphogenesis in the rice blast fungus Magnaporthe grisea.

    PubMed

    Odenbach, Dominik; Breth, Björn; Thines, Eckhard; Weber, Roland W S; Anke, Heidrun; Foster, Andrew J

    2007-04-01

    A strain harbouring an insertion within the promoter of the CON7 gene of Magnaporthe grisea was isolated. This gene was previously shown to be essential for appressorium formation and growth in planta and is predicted to encode a transcription factor. Microarray-based gene expression analysis was used to identify several genes whose transcription during germination depends on Con7p. These include the pathogenicity factor-encoding gene PTH11 and several other genes which like PTH11 are predicted to encode G protein-coupled receptors. Microarray analysis also revealed several Con7p-dependent genes which may encode factors determining cell wall structure or function, either through the synthesis/degradation of cell wall components or by association with the cell exterior. One Con7p-dependent gene predicted to encode a class VII chitin synthase was deleted, leading to dramatic consequences on the pathogenic development of the resultant strain. Within the con7(-) mutant, a 29% reduction in chitin content of germinated spores was found and the mutant was hypersensitive to the chitin synthase inhibitor nikkomycin Z. A green fluorescent protein-tagged Con7p was found to have nuclear localization within spores. Taken together, these observations suggest that Con7p encodes a transcription factor required for the transcription of several genes which participate in disease-related morphogenesis in M. grisea. PMID:17378924

  4. Prevalence and antimicrobial susceptibility pattern of coagulase-negative staphylococci (CoNS) isolated from clinical specimens in Northern of Jordan

    PubMed Central

    Al Tayyar, Ibrahim Ali; AL-Zoubi, Mazhar Salim; Hussein, Emad; Khudairat, Salih; Sarosiekf, Konrad

    2015-01-01

    Background: Coagulase negative Staphylococci (CoNS) are one of the most common bacteria found on human skin and on mucous membranes as a component of normal flora. The presence of CoNS in clinical specimens is frequently associated with an infectious aetiology or contamination. Objectives: We aimed to evaluate CoNS species distribution and susceptibility patterns in specimens obtained from clinics and hospitals in the Northern area of Jordan. Methods: Standard identification methods showed the presence of CoNS in 223 specimens at different local hospitals. Susceptibility testing was performed using 18 antibiotics in accordance with the Clinical and Laboratory Standards Institute (CLSI) recommendations. Results: Staphylococcus epidermidis and S. haemolyticus were found to be the most common species isolated from all specimens representing 122 (54.7%) and 52 (23.4%) of all CoNS species, respectively. Antibiotic susceptibility testing of CoNS species revealed their sensitivity to vancomycin, linozolid, rifampin and nitrofurantin, while showing a highly resistant pattern to ampicillin, penicillin, ceftriaxone, cefazolin, amoxicillin-clavulanic acid and erythromycin. Some variation of the susceptibility pattern of CoNS species were identified in specimens isolated from the ICU and paediatric hospital wards as well as from clinical specimens of urine, blood and catheter tips. Conclusion: The most common CoNS isolates were found to be S. epidermidis and S. haemolyticus with variable percentages according to the specimen source. Moreover, a high susceptibility CoNS to vancomycin, rifampin, and linezolid showed resistance to amoxicillin and penicillin. PMID:26885328

  5. Nanoparticulas basadas en complejos de Fe(II) con transicion de espin: sintesis, caracterizacion y aplicaciones en electronica molecular

    NASA Astrophysics Data System (ADS)

    Monrabal Capilla, Maria

    Esta tesis doctoral esta organizada en 5 capitulos y esta destinada al estudio de sistemas de Fe (II) que presentan el fenomeno de la transicion de espin a escala nanometrica. El capitulo 1 contiene una introduccion general sobre materiales moleculares multifuncionales, destacando aquellos ejemplos mas importantes. Por otro lado, se explicara el fenomeno de la transicion de espin, tratando aspectos conceptuales, los antecedentes mas importantes y la situacion actual. En el capitulo 2 se describen los diferentes procesos existentes para la obtencion de diferentes tipos de nanoparticulas. Ademas, se presenta la sintesis y caracterizacion de nanoparticulas del polimero de coordinacion unidimensional [Fe(Htrz)2(trz)]BF4, obtenidas mediante el metodo de micelas inversas. Estas nanoparticulas, con una estrecha distribucion de tamanos centrada alrededor de los 11 nm, presentan una transicion de espin muy abrupta, con un ancho ciclo de histeresis termica de unos 40K. En el capitulo 3 se describe el proceso de modificacion del tamano de las nanoparticulas descritas en el capitulo anterior, llevado a cabo variando la proporcion de surfactante/H2O en el medio. Ademas, con el objetivo de modificar las propiedades magneticas de las nanoparticulas obtenidas en el capitulo 2, se lleva a cabo la sintesis de nanoparticulas de polimeros de la misma familia del [Fe(Htrz)2(trz)]BF4. En concreto se sintetizaron 3 nuevos tipos de nanoparticulas basadas en el polimero [Fe(Htrz)1-x(NH2trz)x](ClO4)2, siendo x = 0.05, 0.15 y 0.3, en cada caso. Estas nanoparticulas siguen presentando una estrecha distribucion de tamanos y una transicion de espin muy abrupta y con un ancho ciclo de histeresis. Ademas, se observa que este ciclo se desplaza a temperaturas mas proximas a la temperatura ambiente a medida que se aumenta el porcentaje de 4-amino-1, 2, 4- triazol en la muestra. Pero al mismo tiempo se produce una disminucion de la anchura de este ciclo. Por ultimo, en este capitulo se presenta la sintesis de otro nuevo tipo de nanoparticulas, obtenidas a partir de otro polimero de la misma familia, el [FeO8ZnO2(Htrz)3](BF4). Estas nanoparticulas se sintetizaron con el objetivo de estudiar el efecto de la dilucion del metal en la muestra. Como resultado se obtuvieron nanoparticulas que tambien presentan una estrecha distribucion de tamanos pero en este caso la transicion de espin no es tan abrupta como en los casos anteriores. Aunque sigue presentando un ciclo de histeresis termica bastante ancho y a temperaturas proximas a la temperatura ambiente. En el capitulo 4 se describiran las estrategias que se han seguido para mejorar la estabilidad y afinidad sobre diferentes sustratos de las nanoparticulas sintetizadas en el capitulo 2. Tambien se hablara de los intentos realizados parar depositarlas en superficies y embeberlas en diferentes matrices organicas e inorganicas. En el capitulo 5 presentaremos la obtencion de un interruptor molecular realizado poniendo en contacto nanoparticulas individuales sintetizadas en el capitulo 2, con unos electrodos separados varios nanometros. Este dispositivo exhibe "switching" y efecto memoria a temperaturas proximas a la temperatura ambiente como consecuencia de la biestabilidad intrinseca de las nanoparticulas. Ademas demostraremos que el estado magnetico de estas nanoparticulas puede ser controlado electricamente, ya que la transicion de espin en este nanodispositivo molecular puede ser inducida simplemente aplicando un voltaje, lo que puede ser de gran interes para la electronica molecular.

  6. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    NASA Astrophysics Data System (ADS)

    Martinez Mateo, Isidoro Jose

    Mould materials for injection moulding of polymers and polymer-matrix composites represent a relevant industrial economic sector due to the large quantity of pieces and components processed. The material selection for mould manufacturing, its composition and heat treatment, the hardening procedures and machining and finishing processes determine the service performance and life of the mould. In the first part of the present study, the relationship between the hardness and microstructure and the wear resistance of mould steels from large blocks has been studied by pin-on-disc tests, studying the main wear mechanisms. In order to determine the surface damage on mould steels under real injection conditions, different commercial steels have been studied by measuring the variation of surface roughness with the number of injected pieces with different reinforcement percentages and different mould geometries, by using optical profilometry and scanning electron microscopy techniques. It was important to determine the variation of surface roughness of the moulded pieces with the number of injection operations. The materials used were polybutyleneterephthalate pure and reinforced with either 20% or 50% glass fibre. For the different mould designs, the evolution of the glass fibre orientation with injection flow has been determined by image analysis and related to roughness changes and surface damage, both of the composite parts and of the mould steel surface. Finally, the abrasion resistance of the composite parts has been studied by scratch tests as a function of the number of injected parts and of the scratch direction with respect to injection flow and glass fibre orientation. Los materiales para moldes de inyeccion de polimeros y materiales compuestos representan un sector economicamente muy relevante debido al gran aumento del numero de componentes fabricados a partir de materiales polimericos obtenidos mediante moldeo por inyeccion. La seleccion del material para la fabricacion del molde, tienen una gran influencia sobre su comportamiento en servicio a lo largo de la vida util del molde. En la primera parte del presente estudio, a partir de ensayos punzon sobre disco, se ha determinado la relacion entre la resistencia al desgaste y la dureza de aceros para moldes obtenidos a partir de bloques de gran espesor, estudiando los principales mecanismos de desgaste que tienen lugar. A continuacion, con el fin de determinar el dano superficial que sufren los aceros para moldes en condiciones reales de inyeccion, se han estudiado distintos tipos de aceros utilizados comercialmente en moldes de inyeccion de polimeros y materiales compuestos, seleccionando las condiciones de operacion para determinar la variacion de la rugosidad superficial del acero en funcion del material inyectado, del numero de operaciones sucesivas de inyeccion y de la orientacion del flujo de inyeccion, mediante tecnicas de perfilometria optica y microscopia electronica de barrido. Ademas del dano superficial sufrido por el acero con el numero de piezas inyectadas, tambien se ha determinado la evolucion de la rugosidad superficial de los materiales inyectados, polibutilentereftalato (PBT) puro y materiales compuestos derivados de PBT por adicion de un 20 o un 50% en peso de fibra de vidrio. En el caso de las piezas inyectadas, se ha caracterizado su microestructura en funcion del flujo de inyeccion y de la densidad de fibra, se han determinado sus propiedades termicas y dinamico-mecanicas, asi como la variacion de la rugosidad superficial de las piezas inyectadas con el numero de operaciones de inyeccion y con la geometria de las distintas secciones de las piezas. Finalmente, se ha evaluado la resistencia a la abrasion de PBT reforzado con un 50% de fibra, en funcion del numero de piezas inyectadas y de la direccion de rayado con respecto a la orientacion del flujo de inyeccion.

  7. The InterCon network: a program for education partnerships at the University of Texas-Houston Health Science Center.

    PubMed

    Castro, G A; Bouldin, P A; Farver, D W; Maugans, L A; Sanders, L C; Booker, J

    1999-04-01

    The University of Texas-Houston Health Science Center (UT-Houston) has created programs and activities to address the state's pressing needs in minority education. Through InterCon, a network of universities and K-12 schools, UT-Houston works with its partners to identify competitive candidates in the current pool of minority graduates with bachelor's degrees and to help them--along with their non-minority counterparts--progress in their education. Another objective is to expand the pool of minorities underrepresented in medicine who complete high school and go to college. In 1994 UT-Houston and Prairie View A&M University created a collaborative venture to provide new educational opportunities at UT-Houston for Prairie View's predominantly African American students. A three-track summer internship program--a result of that collaboration--has since been expanded to partnerships with other minority and majority universities throughout Texas. In 1998, for example, 108 undergraduate students from these universities (and 40 other universities nationwide) participated in research, professional, and administrative summer internships at UT-Houston. The InterCon network also has partnerships with K-12 schools. UT-Houston works with inner-city, suburban, and rural school districts to develop education models that can be transferred throughout the state. The partnerships deal with helping to teach basic academic skills and computer literacy, improve science-related instruction, meet demands for health promotion materials and information for school-initiated health and wellness programs, and develop distance-learning paradigms. UT-Houston views InterCon as a program helping Texas institutions to engage and adapt to the socioeconomic factors, demographic changes, and technology explosion that currently challenge public education. PMID:10219211

  8. Dietary n-3 PUFA Protects Mice from Con A Induced Liver Injury by Modulating Regulatory T Cells and PPAR-? Expression

    PubMed Central

    Sui, Yongheng; Li, Zhiping; Hua, Jing

    2015-01-01

    Background Dietary n-3 polyunsaturated fatty acids (PUFA) exert anti-inflammatory and immunoregulatory effects through down-regulating the innate and adoptive immune response. However, the effect of dietary n-3 PUFA on CD4+CD25+ regulatory T cells (Tregs) is unclear. Aims The current study was to examine the relationship between n-3 PUFA and Tregs as well as their immunoregulatory effect in immune-mediated liver injury. Methods The mice model feeding with n-3 PUFA-enriched diet was established and Tregs were analyzed. Effect of docosahexaenoic acid (DHA) on Tregs proliferation and induction was determined in vitro. The potential immunotherapeutic effect of dietary n-3 PUFA was investigated through Con A-induced hepatitis model. Results Long-term administration of dietary n-3 PUFA significantly increased hepatic Tregs and modulated their phenotype. n-3 PUFA or DHA directly increased natural Tregs (nTreg) proliferation but didn’t increase inducible Tregs (iTreg). In addition, the expression of peroxisome proliferator activated receptor gamma (PPAR-?), transforming growth factor ? (TGF-?) and interleukin (IL)-10 were significantly up-regulated in n-3 PUFA-enriched diet-fed mice. Finally, n-3 PUFA-enriched diet alleviated liver injury induced by Con A and down-regulated pro-inflammatory cytokines expression, accompanied by increased PPAR-? expression. Conclusion Dietary n-3 PUFA enhanced Tregs generation through up-regulating PPAR-? and TGF-? expression, and protected mice from Con A-induced liver injury. This finding provides a promising potential therapeutic method in treating inflammatory and autoimmune disease. PMID:26177196

  9. Hacia el consumo informado de tabaco en México: efecto de las advertencias con pictogramas en población fumadora

    PubMed Central

    Thrasher, James F; Pérez-Hernández, Rosaura; Arillo-Santillán, Edna; Barrientos-Gutiérrez, Inti

    2015-01-01

    Resumen Objetivo Evaluar el efecto de las advertencias sanitarias (AS) con pictogramas en las cajetillas de tabaco en adultos fumadores. Material y métodos Cohorte de fumadores con representatividad poblacional de siete ciudades mexi canas, antes (2010) y después (2011) de la implementación de AS con pictogramas (ASP). Para determinar el cambio en las variables sobre el impacto cognitivo y conductual de las advertencias, se estimaron modelos bivariados y ajustados de ecuaciones de estimación generalizada. En el Segundo levantamiento (2011), se estimaron modelos para determiner los factores que se asocian con el reporte de recordar cada advertencia que había entrado al mercado, además de los factores asociados con el autorreporte del impacto de cada advertencia vigente. Resultados Se observaron incrementos importantes de 2010 a 2011 en los conocimientos sobre los riesgos de fumar, los componentes tóxicos del tabaco y el número telefónico para recibir consejos sobre dejar de fumar. La recordación e impacto de las primeras advertencias con pictogramas parecen ser amplios y equitativos a través de la población fumadora. En comparación con 2010, un mayor nivel de ex fumadores entrevistados en 2011 reportaron que las advertencias habían influido mucho en dejar de fumar (RM=2.44, 95% IC 1.27–4.72). Conclusiones Las AS con pictogramas han logrado un impacto importante en el conocimiento y conducta, información relevante para la población y en tomadores de decisiones. PMID:22689162

  10. ConBr, a lectin from Canavalia brasiliensis seeds, modulates signaling pathways and increases BDNF expression probably via a glycosylated target.

    PubMed

    Rieger, Débora K; Cunha, Rodrigo M S; Lopes, Mark William; Costa, Ana Paula; Budni, Josiani; Rodrigues, Ana Lúcia S; Walz, Roger; Teixeira, Edson H; Nascimento, Kyria S; Cavada, Benildo S; Leal, Rodrigo B

    2014-12-01

    In the central nervous system, many receptors, ion channels and neurotransmitter transporters are glycoproteins, where the glycan chains are modulator elements. Lectins are proteins, which recognize and bind carbohydrate complexes. We have previously shown that ConBr, a lectin purified from Canavalia brasiliensis seeds, produced antidepressant-like effect and blocked hippocampal neurotoxicity induced by quinolinic acid and glutamate. Noteworthy, all these effects occurred in a dependence of its carbohydrate recognition domain. Therefore, the present study was undertaken in order to elucidate intracellular signaling pathways regulated by ConBr that may be potentially associated with the antidepressant and neuroprotective effects previously reported to be dependent on carbohydrate interaction. ConBr (10?µg/site) was injected into the ventricle (i.c.v.) of mice, and the hippocampi were removed 0.5, 1, 3, 6, 8, 12, 18, and 24?h after treatment. Our results showed that in the period of 0.5-3?h, ConBr induced activation of the protein kinases Akt, ERK1, and PKA. Furthermore, the phosphorylation of CREB-Ser133 was stimulated by ConBr (1-6?h), while brain-derived neurotrophic factor (BDNF) mRNA was increased at 12?h and BDNF protein at 18-24?h. Our data suggest that an early activation of protein kinases may trigger CREB-dependent BDNF transcription, resulting in a subsequent increase of BDNF protein in response to ConBr. Later, increment of Akt phosphorylation was observed 24?h after ConBr administration, possibly due to BDNF/TrkB-dependent activation of Akt. Our findings indicate that ConBr is a multifunctional molecule capable to activate signaling pathways involved in neuroplasticity and neuroprotection. PMID:25319623

  11. Pros and Cons of Using Arrays of Small Antennas Versus Large Single Dish Antennas for the Deep Space Network

    NASA Technical Reports Server (NTRS)

    Bagri, Durgadas S.

    2009-01-01

    This paper briefly describes pros and cons of using arrays of small antennas instead of large single dish antennas for spacecraft telemetry, command, and tracking (TT and C) - communications and navigation (C and N) - and science support that the Deep Space Network (DSN) normally provides. It considers functionality and performance aspects, mainly for TT and C, though it also considers science. It only briefly comments on the cost aspects that seem to favor arrays of small antennas over large single antennas, at least for receiving (downlinks).

  12. Lectin from Canavalia brasiliensis seeds (ConBr) is a valuable biotechnological tool to stimulate the growth of Rhizobium tropici in vitro.

    PubMed

    de Vasconcelos, Mayron Alves; Cunha, Claudio Oliveira; Arruda, Francisco Vassiliepe Sousa; Carneiro, Victor Alves; Mercante, Fabio Martins; do Nascimento Neto, Luiz Gonzaga; de Sousa, Giselly Soares; Rocha, Bruno Anderson Matias; Teixeira, Edson Holanda; Cavada, Benildo Sousa; dos Santos, Ricardo Pires

    2012-01-01

    To study the interactions between a Rhizobium tropici strain and lectins isolated from the seeds of Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr), a lectin fluorescence assay was performed. In addition, an experiment was designed to evaluate the effect of the two lectins on bacterial growth. Both lectins were found to bind to R. tropici cells, but the interactions were inhibited by D-mannose. Interestingly, only ConBr stimulated bacterial growth in proportion to the concentrations used (15.6-500 ?g/mL), and the bacterial growth stimulation was inhibited by D-mannose as well. Structure/Function analyses by bioinformatics were carried out to evaluate the volume and carbohydrate recognition domain (CRD) configuration of ConA and ConBr. The difference of spatial arrangement and volume of CRD may indicate the variation between biological activities of both lectins. The results suggest that ConBr could be a promising tool for studies focusing on the interactions between rhizobia and host plants. PMID:22565477

  13. Actitudes Éticas de los estudiantes y egresados en carrera de medicina con metodologías activas

    PubMed Central

    Novaes, Maria Rita Carvalho Garbi; Novaes, Luiz Carlos Garcez; Guilhem, Dirce; Stepke, Fernando Lolas; Silveira, Carla Cristina Costa; Komatsu, Ricardo Shoiti; Trindade, Eliane Mendonça Vilar; Guiotti, Murilo Galvão

    2010-01-01

    El presente estudio tiene por objeto desarrollar un diagnostico de la inserción integrada de la ética en la carrera de medicina brasileña con una metodología de aprendizaje basada en problemas y describir las percepciones de actitudes éticas de los estudiantes y egresados. El diseño metodológico es un estudio de caso, descriptivo y documental, con abordaje cualitativo y cuantitativo. La muestra de esta investigación ha sido constituida por 120 estudiantes y 40 egresados de dos promociones del Curso de Medicina de la ESCS. Este proyecto fue aprobado por el Comité de Ética en Investigación - SES/DF. Los estudiantes y egresados de la ESCS demostraron un buen manejo en el abordaje de los conflictos éticos y respeto a los pacientes. Sin embargo, el análisis de sensibilidad ética mostró una fragilidad en las percepciones y aptitudes inapropiadas de los estudiantes de la carrera de medicina, identificada básicamente en los años iniciales, que necesitan más discusiones sistematizadas sobre los aspectos éticos y bioéticos integrados a las actividades prácticas para estimular y fortalecer la reflexión ética de los estudiantes. PMID:20981242

  14. EPA site demonstration of the international waste technologies/Geo-Con in-situ stabilization/solidification process

    SciTech Connect

    Stinson, M.K.

    1990-11-01

    The paper presents an EPA evaluation of the first field demonstration of an in situ stabilization/solidification process for contaminated soil under the EPA Superfund Innovative Technology Evaluation (SITE) program. Demonstration of the process was a joint effort of two vendors: International Waste Technologies' (IWT) of Wichita, Kansas, who provided the treatment process, specifically the proprietary additive called HWT-20, and Geo-Con, Inc., of Pittsburgh, Pennsylvania, who provided both engineering and hardware for the in situ soil treatment. The field demonstration took place in April, 1988 at a site contaminated mainly with polychlorinated biphenyls (PCBs). EPA tested the soil before and after treatment and the EPA evaluation of the process is based on results from the testing. A year later, in April 1989, EPA tested again the treated soil and results of that testing were compared to those of the demonstration. Results of the EPA evaluation of the IWT process, the Geo-Con performance, and treatment costs are discussed separately.

  15. Desarrollo de la Escala sobre el Estigma Relacionado con el VIH/SIDA para Profesionales de la Salud mediante el uso de métodos mixtos123

    PubMed Central

    Varas-Díaz, Nelson; Neilands, Torsten B.; Guilamo-Ramos, Vincent; Cintrón Bou, Francheska N.

    2009-01-01

    El estigma relacionado con el VIH/SIDA continúa siendo un obstáculo para la prevención primaria y secundaria del VIH. Las consecuencias para las personas que viven con la enfermedad han sido muy documentadas y continúan siendo una gran preocupación para las personas que proveen servicios de salud y para aquellas que investigan el tema. Estas consecuencias son preocupantes cuando el estigma emana de profesionales de la salud porque se puede limitar el acceso a los servicios. Uno de los principales obstáculos para la investigación del estigma relacionado con el VIH en Puerto Rico es la falta de instrumentos cuantitativos para evaluar las manifestaciones del estigma entre profesionales de la salud. El objetivo principal de este estudio fue desarrollar y probar las propiedades psicométricas de una escala sobre el estigma relacionado con el VIH/SIDA culturalmente apropiada para personas que proveen servicios de salud puertorriqueñas y desarrollar una versión corta de la escala que pudiera usarse en escenarios clínicos con tiempo limitado. El instrumento desarrollado estuvo basado en evidencia cualitativa recopilada entre profesionales y estudiantes de profesiones de la salud puertorriqueños/as (n=80) y administrado a una muestra de 421 profesionales de la salud en adiestramiento. La escala contenía 12 dimensiones del estigma relacionado con el VIH/SIDA. El análisis cuantitativo corroboró 11 de ellas, teniendo como resultado un instrumento con validez y confiabilidad satisfactoria. Estas dimensiones, a su vez, fueron subcomponentes de un factor de estigma general superior. PMID:20333258

  16. Modelo de accesibilidad de conceptos matematicos aplicados en el curso de Astronomia Descriptiva para estudiantes con impedimentos visuales en la UPR

    NASA Astrophysics Data System (ADS)

    Isidro Villamizar, Gloria Maria

    Este estudio utiliza metodologia de investigacion cualitativa, con el proposito de describir, analizar y evaluar los procesos de diseno y desarrollo de un modelo de accesibilidad que consiste en estrategias de ensenanza de las matematicas para estudiantes con impedimentos visuales matriculados en el curso de Astronomia Descriptiva en la UPR. Se utilizaron las siguientes estrategias para recopilar la informacion, 1) reflexiones de la investigadora en el proceso de diseno y desarrollo de las lecciones adaptadas, que se registraron en un diario reflexivo. 2) entrevista semiestructurada luego de haber trabajado las lecciones de aprendizaje adaptadas con los participantes. 3) observaciones y notas de la investigadora del trabajo de los participantes. Para obtener la informacion de los participantes se obtuvo los permisos institucionales necesarios; se seleccionaron los participantes y se validaron los instrumentos; se realizo el desarrollo de las lecciones adaptadas con los participantes; y finalmente, se analizo la informacion obtenida. El diseno de las lecciones de aprendizaje adaptadas se hizo siguiendo las recomendaciones curriculares de los temas de matematicas aplicados en el curso de Astronomia Descriptiva realizado por la investigadora durante su semestre de internado. El testimonio de las voces de los participantes se obtuvo del proceso de desarrollo de las lecciones de aprendizaje adaptadas de temas seleccionados de conceptos matematicos requeridos en el curso de Astronomia Descriptiva y de la entrevista semiestructurada con los participantes, luego de haber trabajado las lecciones de aprendizaje. Para el desarrollo de las lecciones de aprendizaje, se utilizaron materiales tactiles adaptados, materiales tactiles disenados y materiales disponibles comercialmente. Los textos de las lecciones se imprimieron en tinta y en Braille. Se exhorta a disenar y desarrollar estrategias de ensenanza accesibles, considerando como recursos para evaluar su efectividad a personas con impedimentos visuales. El utilizar estrategias de aprendizaje accesibles de acuerdo a las necesidades individuales de los estudiantes, contribuye para que los estudiantes con impedimentos visuales descubran, exploren, investiguen y formulen sus propias conclusiones durante su proceso de aprendizaje.

  17. Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina.

    PubMed

    Carballo-Diéguez, Alex; Avila, María M; Balán, Iván C; Marone, Rubén; Pando, María A; Barreda, Victoria

    2011-03-01

    Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  18. Presentación del estudio “Links” de hombres que tienes sexo con hombres en Buenos Aires, Argentina

    PubMed Central

    Carballo-Diéguez, Alex; Ávila, María M; Balán, Iván C.; Marone, Rubén; Pando, María A.; Barreda, Victoria

    2011-01-01

    Resumen Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos (“teteras”), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  19. Protective Effects of Astaxanthin on ConA-Induced Autoimmune Hepatitis by the JNK/p-JNK Pathway-Mediated Inhibition of Autophagy and Apoptosis

    PubMed Central

    Liu, Tong; Wang, Junshan; Dai, Weiqi; Wang, Fan; Zheng, Yuanyuan; Chen, Kan; Li, Sainan; Abudumijiti, Huerxidan; Zhou, Zheng; Wang, Jianrong; Lu, Wenxia; Zhu, Rong; Yang, Jing; Zhang, Huawei; Yin, Qin; Wang, Chengfen; Zhou, Yuqing; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

    2015-01-01

    Objective Astaxanthin, a potent antioxidant, exhibits a wide range of biological activities, including antioxidant, atherosclerosis and antitumor activities. However, its effect on concanavalin A (ConA)-induced autoimmune hepatitis remains unclear. The aim of this study was to investigate the protective effects of astaxanthin on ConA-induced hepatitis in mice, and to elucidate the mechanisms of regulation. Materials and Methods Autoimmune hepatitis was induced in in Balb/C mice using ConA (25 mg/kg), and astaxanthin was orally administered daily at two doses (20 mg/kg and 40 mg/kg) for 14 days before ConA injection. Levels of serum liver enzymes and the histopathology of inflammatory cytokines and other maker proteins were determined at three time points (2, 8 and 24 h). Primary hepatocytes were pretreated with astaxanthin (80 μM) in vitro 24 h before stimulation with TNF-α (10 ng/ml). The apoptosis rate and related protein expression were determined 24 h after the administration of TNF-α. Results Astaxanthin attenuated serum liver enzymes and pathological damage by reducing the release of inflammatory factors. It performed anti-apoptotic effects via the descending phosphorylation of Bcl-2 through the down-regulation of the JNK/p-JNK pathway. Conclusion This research firstly expounded that astaxanthin reduced immune liver injury in ConA-induced autoimmune hepatitis. The mode of action appears to be downregulation of JNK/p-JNK-mediated apoptosis and autophagy. PMID:25761053

  20. Quercetin Protects Mice from ConA-Induced Hepatitis by Inhibiting HMGB1-TLR Expression and Down-Regulating the Nuclear Factor Kappa B Pathway.

    PubMed

    Li, Xi; Liu, Hong-Chun; Yao, Qun-Yan; Xu, Bei-Li; Zhang, Shun-Cai; Tu, Chuan-Tao

    2016-02-01

    The dietary flavonoid quercetin has hepatoprotective effects. We analyzed the effects of quercetin on concanavalin A (ConA)-induced hepatitis in mice and its underlying molecular mechanisms of action. Mice were administered quercetin (50 mg/kg body weight, i.p.) or vehicle 30 min before intravenous administration of ConA. Quercetin pretreatment significantly reduced the ConA-induced elevations in plasma aminotransferase concentrations and liver necrosis, as well as reducing serum concentrations of the pro-inflammatory cytokines tumor necrosis factor (TNF)-?, interferon-?, and interleukin-4. Quercetin pretreatment also reduced expression of high-mobility group box 1 protein (HMGB1) and toll-like receptor (TLR)-2 and TLR-4 messenger RNA (mRNA) and protein in liver tissues. Quercetin pretreatment significantly inhibited degradation of inhibitory kappa B alpha and modulated ConA-induced nuclear translocation in the liver of nuclear factor kappa B (NF-?B) p65. These results demonstrate that quercetin protects against ConA-mediated hepatitis in mice by attenuating the HMGB1-TLRs-NF-?B signaling pathway. PMID:26267064

  1. A New Method for Re-Analyzing Evaluation Bias: Piecewise Growth Curve Modeling Reveals an Asymmetry in the Evaluation of Pro and Con Arguments

    PubMed Central

    Jirschitzka, Jens; Kimmerle, Joachim; Cress, Ulrike

    2016-01-01

    In four studies we tested a new methodological approach to the investigation of evaluation bias. The usage of piecewise growth curve modeling allowed for investigation into the impact of people’s attitudes on their persuasiveness ratings of pro- and con-arguments, measured over the whole range of the arguments’ polarity from an extreme con to an extreme pro position. Moreover, this method provided the opportunity to test specific hypotheses about the course of the evaluation bias within certain polarity ranges. We conducted two field studies with users of an existing online information portal (Studies 1a and 2a) as participants, and two Internet laboratory studies with mostly student participants (Studies 1b and 2b). In each of these studies we presented pro- and con-arguments, either for the topic of MOOCs (massive open online courses, Studies 1a and 1b) or for the topic of M-learning (mobile learning, Studies 2a and 2b). Our results indicate that using piecewise growth curve models is more appropriate than simpler approaches. An important finding of our studies was an asymmetry of the evaluation bias toward pro- or con-arguments: the evaluation bias appeared over the whole polarity range of pro-arguments and increased with more and more extreme polarity. This clear-cut result pattern appeared only on the pro-argument side. For the con-arguments, in contrast, the evaluation bias did not feature such a systematic picture. PMID:26840219

  2. Accurate macromolecular crystallographic refinement: incorporation of the linear scaling, semiempirical quantum-mechanics program DivCon into the PHENIX refinement package

    SciTech Connect

    Borbulevych, Oleg Y.; Plumley, Joshua A.; Martin, Roger I.; Merz, Kenneth M. Jr; Westerhoff, Lance M.

    2014-05-01

    Semiempirical quantum-chemical X-ray macromolecular refinement using the program DivCon integrated with PHENIX is described. Macromolecular crystallographic refinement relies on sometimes dubious stereochemical restraints and rudimentary energy functionals to ensure the correct geometry of the model of the macromolecule and any covalently bound ligand(s). The ligand stereochemical restraint file (CIF) requires a priori understanding of the ligand geometry within the active site, and creation of the CIF is often an error-prone process owing to the great variety of potential ligand chemistry and structure. Stereochemical restraints have been replaced with more robust functionals through the integration of the linear-scaling, semiempirical quantum-mechanics (SE-QM) program DivCon with the PHENIX X-ray refinement engine. The PHENIX/DivCon package has been thoroughly validated on a population of 50 protein–ligand Protein Data Bank (PDB) structures with a range of resolutions and chemistry. The PDB structures used for the validation were originally refined utilizing various refinement packages and were published within the past five years. PHENIX/DivCon does not utilize CIF(s), link restraints and other parameters for refinement and hence it does not make as many a priori assumptions about the model. Across the entire population, the method results in reasonable ligand geometries and low ligand strains, even when the original refinement exhibited difficulties, indicating that PHENIX/DivCon is applicable to both single-structure and high-throughput crystallography.

  3. A New Method for Re-Analyzing Evaluation Bias: Piecewise Growth Curve Modeling Reveals an Asymmetry in the Evaluation of Pro and Con Arguments.

    PubMed

    Jirschitzka, Jens; Kimmerle, Joachim; Cress, Ulrike

    2016-01-01

    In four studies we tested a new methodological approach to the investigation of evaluation bias. The usage of piecewise growth curve modeling allowed for investigation into the impact of people's attitudes on their persuasiveness ratings of pro- and con-arguments, measured over the whole range of the arguments' polarity from an extreme con to an extreme pro position. Moreover, this method provided the opportunity to test specific hypotheses about the course of the evaluation bias within certain polarity ranges. We conducted two field studies with users of an existing online information portal (Studies 1a and 2a) as participants, and two Internet laboratory studies with mostly student participants (Studies 1b and 2b). In each of these studies we presented pro- and con-arguments, either for the topic of MOOCs (massive open online courses, Studies 1a and 1b) or for the topic of M-learning (mobile learning, Studies 2a and 2b). Our results indicate that using piecewise growth curve models is more appropriate than simpler approaches. An important finding of our studies was an asymmetry of the evaluation bias toward pro- or con-arguments: the evaluation bias appeared over the whole polarity range of pro-arguments and increased with more and more extreme polarity. This clear-cut result pattern appeared only on the pro-argument side. For the con-arguments, in contrast, the evaluation bias did not feature such a systematic picture. PMID:26840219

  4. Selenium promotes T-cell response to TCR-stimulation and ConA, but not PHA in primary porcine splenocytes.

    PubMed

    Ren, Fei; Chen, Xingxiang; Hesketh, John; Gan, Fang; Huang, Kehe

    2012-01-01

    There is controversy in the literature over whether the selenium (Se) influences cellular immune responses, and the mechanisms possibly underlying these effects are unclear. In this study, the effects of Se on T-cell proliferation and IL-2 production were studied in primary porcine splenocytes. Splenocytes were treated with different mitogens in the presence of 0.5-4 µmol/L sodium selenite. Se significantly promoted T-cell receptor (TCR) or concanavalin A (ConA)-induced T-cell proliferation and IL-2 production but failed to regulate T-cell response to phytohemagglutinin (PHA). In addition, Se significantly increased the levels of cytosolic glutathione peroxidase (GPx1) and thioredoxin reductase 1 (TR1) mRNA, the activity of GPx1 and the concentration of reduced glutathione (GSH) in the unstimulated, or activated splenocytes. These results indicated that Se improved the redox status in all splenocytes, including unstimulated, TCR, ConA and PHA -stimulated, but only TCR and ConA-induced T-cell activation was affected by the redox status. N-acetylcysteine (NAC), a pharmacological antioxidant, increased T-cell proliferation and IL-2 production by TCR and ConA stimulated splenocytes but had no effect on the response to PHA in primary porcine splenocytes confirming that PHA-induced T-cell activation is insensitive to the redox status. We conclude that Se promotes GPx1 and TR1 expression and increases antioxidative capacity in porcine splenocytes, which enhances TCR or ConA -induced T-cell activation but not PHA-induced T-cell activation. The different susceptibilities to Se between the TCR, ConA and PHA -induced T-cell activation may help to explain the controversy in the literature over whether or not Se boosts immune responses. PMID:22530011

  5. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    The aim is to analyse the negative influence of high panel temperatures on electrical production when they are placed on steel roofs of industrial buildings and greenhouse roofs. Different configurations have been tested in order to allow cooling of photovoltaic panels to decrease panel temperature and improve electrical performance. To research this problem two experimental facilities have been built. The first facility includes two panels fixed on a structure. A panel is integrated on a parallel steel plate which does not allow sufficient cooling. Between both surfaces, there is an open air channel in which an air flow is created by the chimney effect thus cooling the panel by natural convection or inducing air, using a fan, by forced convection. The other panel has not any plate underneath it and is used as a referent. The electrical behaviour of the integrated panel has been studied for different air gaps and induced velocities, being also compared with the reference panel. An experimental model was developed to establish correlations which allow determine the panel temperature depending on the influential variables on the cooling ability. This research also analyses the data of a working solar plant, with the same panel model, obtaining the correlations between electrical variables and panel temperature. A comparison with the electrical behaviour in the experimental facility and the solar plant is also presented. The second experimental facility is a replica of a photovoltaic greenhouse. It consists of four photovoltaic panels placed on the plastic roof, providing an open and divergent channel between both surfaces thus creating an air flow by natural convection. This research studies the effect of high temperatures within the greenhouse which is transferred by the roof and thus affects the electrical production. In addition, two air gaps were used and the effect of adding insulating material to the plastic roof was studied. The electrical variables of the panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la influencia de las altas temperaturas en el interior del invernadero sobre la produccion electrica de los paneles, decido a la transferencia de calor del interior del invernadero. Ademas, se han ensayado dos separaciones diferentes y para cada una se ha comparado con la misma, utilizando un aislante sobre la cubierta. El estudio realizado sobre ambas instalaciones ha proporcionado un conocimiento profundo del funcionamiento de cada una de ellas, asi como informacion valida para una mejora de futuros disenos de instalaciones fotovoltaicas sobre cubiertas.

  6. Inversor Resonante de Tres Elementos L-LC con Caracteristica Cortocircuitable para Aplicaciones de Calentamiento por Induccion

    NASA Astrophysics Data System (ADS)

    Espi Huerta, Jose Miguel

    Los generadores de calentamiento por induccion son puentes inversores con carga resonante, cuya mision es basicamente crear una corriente sinusoidal de gran amplitud sobre la "bobina de caldeo", que forma parte del tanque resonante. En el interior de esta bobina se introduce la pieza que se desea calentar. EI campo magnetico creado induce corrientes superficiales (corrientes de Foucault) sobre la pieza, que producen su calentamiento. Los tanques resonantes (tambien llamados osciladores) utilizados en la actualidad son el resonante serie y el resonante paralelo. Aunque ya desde hace algun tiempo se vienen construyendo generadores de alta potencia basados en estos dos osciladores, el exito nunca ha. sido completo en ninguno de los dos casos. Tal y como se explica en la introduccion de esta memoria, los puentes inversores utilizados deben operar sobre una carga inductiva (corriente retrasada) para evitar el fenomeno de la recuperacion inversa de sus diodos y la consiguiente ruptura de los transistores. De la restriccion topologica anterior se deduce que el generador paralelo debe conmutar a frecuencias inferiores a la resonancia, y el serie a frecuencias superiores. A esta restriccion topologica hay que unir otra que es exclusiva del calentamiento por induccion: La corriente por la bobina de caldeo debe ser sinusoidal. De no ser asi, resultaria imposible disponer toda la potencia de calentamiento sobre la pieza en el espesor requerido por la aplicacion. Como consecuencia, los inversores no pueden operar por debajo de la frecuencia de resonancia del oscilador, pues en ese caso se amplifican los armonicos de orden superior de la tension/corriente de entrada situados sobre la resonancia, con la consiguiente distorsion de la corriente de salida. La conjuncion de las dos restricciones anteriores obligan al inversor paralelo a funcionar a la frecuencia de resonancia del oscilador. Esto imposibilita un control por variacion de frecuencia, regulandose la potencia desde la seccion de entrada mediante un mayor o menor aporte de corriente al puente. Como consecuencia, la seccion de entrada del paralelo, ya de por si mas voluminosa que lao del serie por el uso de grandes componentes magneticos (bobinas de filtro o de "alisamiento"), result a tambien mas complicada y costosa debido a la necesidad de ser implementada mediante rectificador controlado. Ademas, la regulacion que ofrece el rectificador es pobre, dada su baja frecuencia de conmutacion. En cambio, el circuito serie puede funcionar por encima de la resonancia manteniendo una secuencia de conmutacion sin riesgos de recuperacion inversa y con una corriente de salida practicamente sinusoidal, lo que permite un control de la potencia por variacion de frecuencia. Puesto que la tarea de regulacion se realiza desde el puente inversor, la regulacion resulta mucho mas eficaz y la seccion de entrada se puede implementar mediante un simple rectificador no controlado y un condensador de filtro. (Abstract shortened by UMI.).

  7. Studies on prevalence of biofilm associated genes and primary observation on sasX gene in clinical isolates of coagulase negative staphylococci (CoNS).

    PubMed

    Soumya, Kandammuriyil Radhakrishnan; Mathew, Shiji; Sugathan, Sheela; Mathew, Jyothis; Radhakrishnan, Edayileveettil Krishnankutty

    2016-04-01

    Coagulase negative staphylococci (CoNS) are nosocomial pathogens that cause indwelling medical device associated infections due to its biofilm forming potential and multiple antibiotic resistance. The current study focused on species identification, antibiotic resistance profile and molecular basis of biofilm formation and attachment of CoNS isolated from clinical samples. Along with this, molecular screening for mecA and newly identified surface colonization protein encoded by sasX gene was also conducted. S. epidermidis (n = 19, 47%) was identified as the most prevalent CoNS species and very interestingly two biofilm forming, mecA positive S. epidermidis isolates were found to carry all the biofilm associated genes screened in this study, which indicates its potential to form the strong biofilm. Another novel observation of the study is the detection of sasX gene in one biofilm positive S. epidermidis isolate. The study also identified one doxycycline resistant mecA positive, multidrug resistant S. haemolyticus isolate. In conclusion, the study signifies the existence of multiple biofilm related genes, multidrug resistance and the presence of sasX gene among clinical isolates of CoNS. PMID:26847412

  8. Accurate macromolecular crystallographic refinement: incorporation of the linear scaling, semiempirical quantum-mechanics program DivCon into the PHENIX refinement package

    PubMed Central

    Borbulevych, Oleg Y.; Plumley, Joshua A.; Martin, Roger I.; Merz, Kenneth M.; Westerhoff, Lance M.

    2014-01-01

    Macromolecular crystallographic refinement relies on sometimes dubious stereochemical restraints and rudimentary energy functionals to ensure the correct geometry of the model of the macromolecule and any covalently bound ligand(s). The ligand stereochemical restraint file (CIF) requires a priori understanding of the ligand geometry within the active site, and creation of the CIF is often an error-prone process owing to the great variety of potential ligand chemistry and structure. Stereochemical restraints have been replaced with more robust functionals through the integration of the linear-scaling, semiempirical quantum-mechanics (SE-QM) program DivCon with the PHENIX X-ray refinement engine. The PHENIX/DivCon package has been thoroughly validated on a population of 50 protein–ligand Protein Data Bank (PDB) structures with a range of resolutions and chemistry. The PDB structures used for the validation were originally refined utilizing various refinement packages and were published within the past five years. PHENIX/DivCon does not utilize CIF(s), link restraints and other parameters for refinement and hence it does not make as many a priori assumptions about the model. Across the entire population, the method results in reasonable ligand geometries and low ligand strains, even when the original refinement exhibited difficulties, indicating that PHENIX/DivCon is applicable to both single-structure and high-throughput crystallography. PMID:24816093

  9. Tensión postraumática relacionada con el cáncer (PDQ)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca de la tensión postraumática y síntomas relacionados en los pacientes con cáncer, sobrevivientes del cáncer y miembros de la familia. Se discuten la evaluación y tratamiento de estos síntomas.

  10. Tensión postraumática relacionada con el cáncer (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de la tensión postraumática y los síntomas relacionados en los pacientes con cáncer, sobrevivientes del cáncer y miembros de la familia. Se discuten la evaluación y el tratamiento de estos síntomas.

  11. Aumento de la supervivencia en hombres con cáncer de próstata metastásico que reciben quimioterapia

    Cancer.gov

    Los hombres con cáncer de próstata metastásico sensible a las hormonas que recibieron el fármaco quimioterapéutico docetaxel al inicio de la terapia hormonal convencional vivieron más tiempo que los pacientes que recibieron solo terapia hormonal, de acuer

  12. Beneficios y riesgos de la terapia estrogénica en la menopausia varían por edad, de acuerdo con el e

    Cancer.gov

    Los datos de seguimiento a largo plazo del estudio Iniciativa para la Salud de la Mujer (WHI) proporcionan información nueva e importante sobre los posibles riesgos y beneficios de la terapia hormonal para tratar síntomas relacionadas con la menopausia.

  13. Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material.

    PubMed

    Dinakaran, Paul M; Kalainathan, S

    2013-07-01

    4-Chloro 4-nitrostilbene (CONS) a new organic nonlinear optical material has been synthesized. Employing slow evaporation method, good optical quality single crystals (dimensions up to 6×2×3 mm(3)) have been grown using ethyl methyl ketone (EMK) as a solvent. The grown crystals have been subjected to various characterizations such as single crystal X-ray diffraction, powder XRD, Fourier Transform Infrared spectroscopy (FTIR), proton NMR, solid UV absorption, SHG studies. Single crystal X-ray diffraction reveals that the crystal system belongs to monoclinic with noncentrosymmetric space group P21. The UV-Vis absorption spectrum has been recorded and found that the cut off wavelength is 380 nm. Functional groups and the structure of the title compound have been confirmed by FTIR and (1)H NMR spectroscopic analyses respectively. Molecular mass of the CONS confirmed by the high resolution mass spectral analysis .The thermal behavior of the grown crystal has been studied by TG/DTA analysis and it shows the melting point is at 188.66 °C. Dislocations and growth pattern present in the grown crystal revealed by the etching study. The mechanical strength of the CONS crystal has been studied by Vicker's hardness measurement. The SHG efficiency of the grown crystal has been determined by Kurtz and Perry powder test which revealed that the CONS crystal (327 mV) has 15 times greater efficiency than that of KDP (21.7 mV). PMID:23624038

  14. Analysis of cancer risk and BRCA1 and BRCA2 mutation prevalence in the kConFab familial breast cancer resource

    PubMed Central

    Mann, Graham J; Thorne, Heather; Balleine, Rosemary L; Butow, Phyllis N; Clarke, Christine L; Edkins, Edward; Evans, Gerda M; Fereday, Sián; Haan, Eric; Gattas, Michael; Giles, Graham G; Goldblatt, Jack; Hopper, John L; Kirk, Judy; Leary, Jennifer A; Lindeman, Geoffrey; Niedermayr, Eveline; Phillips, Kelly-Anne; Picken, Sandra; Pupo, Gulietta M; Saunders, Christobel; Scott, Clare L; Spurdle, Amanda B; Suthers, Graeme; Tucker, Kathy; Chenevix-Trench, Georgia

    2006-01-01

    Introduction The Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab) is a multidisciplinary, collaborative framework for the investigation of familial breast cancer. Based in Australia, the primary aim of kConFab is to facilitate high-quality research by amassing a large and comprehensive resource of epidemiological and clinical data with biospecimens from individuals at high risk of breast and/or ovarian cancer, and from their close relatives. Methods Epidemiological, family history and lifestyle data, as well as biospecimens, are collected from multiple-case breast cancer families ascertained through family cancer clinics in Australia and New Zealand. We used the Tyrer-Cuzick algorithms to assess the prospective risk of breast cancer in women in the kConFab cohort who were unaffected with breast cancer at the time of enrolment in the study. Results Of kConFab's first 822 families, 518 families had multiple cases of female breast cancer alone, 239 had cases of female breast and ovarian cancer, 37 had cases of female and male breast cancer, and 14 had both ovarian cancer as well as male and female breast cancer. Data are currently held for 11,422 people and germline DNAs for 7,389. Among the 812 families with at least one germline sample collected, the mean number of germline DNA samples collected per family is nine. Of the 747 families that have undergone some form of mutation screening, 229 (31%) carry a pathogenic or splice-site mutation in BRCA1 or BRCA2. Germline DNAs and data are stored from 773 proven carriers of BRCA1 or BRCA1 mutations. kConFab's fresh tissue bank includes 253 specimens of breast or ovarian tissue – both normal and malignant – including 126 from carriers of BRCA1 or BRCA2 mutations. Conclusion These kConFab resources are available to researchers anywhere in the world, who may apply to kConFab for biospecimens and data for use in ethically approved, peer-reviewed projects. A high calculated risk from the Tyrer-Cuzick algorithms correlated closely with the subsequent occurrence of breast cancer in BRCA1 and BRCA2 mutation positive families, but this was less evident in families in which no pathogenic BRCA1 or BRCA2 mutation has been detected. PMID:16507150

  15. Aspergilosis cervical con diseminación al sistema nervioso central. Presentación de un caso y revisión de bibliografía

    PubMed Central

    Vergara, Guillermo Enrique; Roura, Natalia; del Castillo, Marcelo; Mora, Andrea; Alcorta, Santiago Condomi; Mormandi, Rubén; Cervio, Andrés; Salvat, Jorge

    2015-01-01

    Introducción: la Aspergilosis Invasiva (AI) del Sistema Nervioso Central (SNC) es infrecuente y ocurre generalmente en pacientes inmunocomprometidos. Puede presentarse con cuadros de meningitis, aneurismas micóticos, infartos o abscesos. Es una infección con pronóstico reservado y puede afectar el SNC de forma primaria o secundaria a partir de un foco que se disemina por vía hematógena. Presentamos el caso de un paciente con AI con invasión primaria a nivel óseo y diseminación posterior al cerebro. Caso clínico: Paciente masculino de 25 años con diagnóstico de leucemia linfática aguda en tratamiento quimioterápico que presentó neumonitis por metotrexate por lo que inicia tratamiento con corticoides. Posteriormente agregó cervicalgia y con el diagnóstico de osteomielitis cervical se realiza punción bajo tomografía computada (TC) sin aislarse gérmenes. Se colocó Halo Vest e inició tratamiento antibiótico empírico. Posteriormente presentó afasia de expresión secundaria a lesión frontal izquierda. Se realizó evacuación de absceso cerebral aislando A. fumigatus. El tratamiento antibiótico específico posterior permitió una buena respuesta clínica y radiológica. Conclusión: La presencia de lesiones en el SNC de pacientes inmunocomprometidos debe incluir a las micosis como diagnóstico diferencial. La evacuación quirúrgica permite llegar rápidamente al diagnóstico mejorando la respuesta posterior al tratamiento antibiótico. Para evaluar la respuesta terapéutica y posibles recaídas se debe realizar un seguimiento periódico clínico radiológico. Palabras clave: Aspergilosis cerebral; Aspergilosis cervical; Aspergilosis invasiva; Voriconazol. PMID:26600985

  16. Laboratory simulation of Kuiper belt object volatile ices under ionizing radiation: CO-N2 ices as a case study.

    PubMed

    Kim, Y S; Zhang, F; Kaiser, R I

    2011-09-21

    The exposure of icy Kuiper belt objects (KBOs) by ionizing radiation was simulated in this case of exposing carbon monoxide-nitrogen (CO-N(2)) ices by energetic electrons. The radiation-induced chemical processing was monitored on-line and in situ via FTIR spectroscopy and quadrupole mass spectrometry. Besides the array of carbon oxides being reproduced as in neat irradiated carbon monoxide (CO) ices studied previously, the radiation exposure at 10 K resulted in the formation of nitrogen-bearing species of isocyanato radical (OCN), linear (l-NCN), nitric oxide (NO), nitrogen dioxide (NO(2)), plus diazirinone (N(2)CO). The infrared assignments of these species were further confirmed by isotopic shifts. The temporal evolution of individual species was found to fit in first-order reaction schemes, prepping up the underlying non-equilibrium chemistry on the formation of OCN, l-NCN, and NO radicals in particular. Also unique to the binary KBO model ices and viable for the future remote detection is diazirinone (N(2)CO) at 1860 cm(-1) (2?(5)) formed at lower radiation exposure. PMID:21687881

  17. Circulating microRNA Biomarkers as Liquid Biopsy for Cancer Patients: Pros and Cons of Current Assays

    PubMed Central

    Ono, Shigeshi; Lam, Stella; Nagahara, Makoto; Hoon, Dave S. B.

    2015-01-01

    An increasing number of studies have focused on circulating microRNAs (cmiRNA) in cancer patients’ blood for their potential as minimally-invasive biomarkers. Studies have reported the utility of assessing specific miRNAs in blood as diagnostic/prognostic biomarkers; however, the methodologies are not validated or standardized across laboratories. Unfortunately, there is often minimum limited overlap in techniques between results reported even in similar type studies on the same cancer. This hampers interpretation and reliability of cmiRNA as potential cancer biomarkers. Blood collection and processing, cmiRNA extractions, quality and quantity control of assays, defined patient population assessment, reproducibility, and reference standards all affect the cmiRNA assay results. To date, there is no reported definitive method to assess cmiRNAs. Therefore, appropriate and reliable methodologies are highly necessary in order for cmiRNAs to be used in regulated clinical diagnostic laboratories. In this review, we summarize the developments made over the past decade towards cmiRNA detection and discuss the pros and cons of the assays. PMID:26512704

  18. Should a Preschool Child with Acute Episodic Wheeze be Treated with Oral Corticosteroids? A Pro/Con Debate.

    PubMed

    Beigelman, Avraham; Durrani, Sandy; Guilbert, Theresa W

    2016-01-01

    Traditionally, preschool-aged children with an acute wheezing episode have been treated with oral corticosteroids (OCSs) based on the efficacy of OCSs in older children and adolescents. However, this practice has been recently challenged based on the results of recent studies. The argument supporting the use of OCSs underscores the observation that many children with recurrent preschool wheezing develop atopic disease in early life which predicts both an increased risk to develop asthma in later life and response to OCS therapy. Further, review of the literature demonstrates heterogeneity of study designs, OCS dosage, interventions, study medication adherence, and settings and overall lack of predefined preschool wheezing phenotypes. The heterogeneity of these studies does not allow a definitive recommendation discouraging OCS use. Advocates against the use of OCSs in this population argue that most of studies investigating the efficacy of OCSs in acute episodic wheeze in preschool-aged children have not demonstrated beneficial effects. Moreover, repeated OCS bursts may be associated with adverse effects. Finally, both sides can agree that there is a significant need to conduct efficacy trials evaluating OCS treatment in preschool-aged children with recurrent wheezing targeted at phenotypes that would be expected to respond to OCSs. This article presents a summary of recent literature regarding the use of OCSs for acute episodic wheezing in preschool-aged children and a "pro" and "con" debate for such use. PMID:26772924

  19. Virgin Caenorhabditis remanei females are attracted to a coital pheromone released by con-specific copulating males

    PubMed Central

    Markert, Mathew; García, Luis René

    2013-01-01

    The gonochoristic soil nematode Caenorhabditis remanei strictly requires copulation for species propagation. Males of this species are sexually promiscuous with females of other species; therefore, we asked in this study whether virgin C. remanei females display evidence of mate choice. We digitally recorded and measured the locomotor behaviors of one or more virgin females in the presence of a single male on a 5 mm diameter mating lawn. We observed that initially only the male modifies his locomotor trajectory to another animal on the mating lawn; the virgin females showed no locomotor bias toward the mate-searching male. However, once a male started to copulate, females in the vicinity altered their movement trajectories toward the copulating couple. Newly inseminated females are refractive to the coital signal, but partially regain their attraction to copulating males after 24 h. We found only copulating males with an intact gonad can attract females, and that the coital signal can be broadcasted at least 1.5 mm through the air. Unlike males, which are also attracted to hetero-specific females, virgin C. remanei females will only crawl toward a copulating con-specific male. We suggest that Caenorhabditis females use the coital signal as a pheromone to identify a vigorous male of their own species. PMID:24058874

  20. Structural, electronic and magnetic properties of ConPt, for M=13, 19, and 55, from first principles

    NASA Astrophysics Data System (ADS)

    Montejano-Carrizales, J. M.; Aguilera-Granja, F.; Goyhenex, C.; Pierron-Bohnes, V.; Morán-López, J. L.

    2014-04-01

    The geometrical structure, chemical ordering, electronic and magnetic properties of ConPt, for M=13, 19, and 55, are investigated, within the framework of the density functional theory as implemented in the SIESTA code. For the exchange and correlation potential, we used the Perdew-Burke-Ernzerhof (PBE) form of the generalized gradient approximation (GGA). We considered the hexagonal, the cubo-octahedral (CO), the centered pentagonal prism (CPP), and the icosahedral (ICO) geometries. We found that the CO, ICO, and CPP structures have similar energies and the lowest energy configuration changes as a function of the Co concentration and cluster size. In most of the cases, around the equiatomic concentration, the Co and Pt atoms form chemically ordered structures, but most often not the L10 structure stable in bulk. We observed that the Pt atoms are segregated to the surface in all the concentration range. A detailed analysis of the dependence of the magnetic moment of the components, and their average, as a function of structure and of chemical composition is reported. A strong polarization of the Pt atoms by the nearest neighbor Co atoms is observed.

  1. Spleen deflation and beyond: the pros and cons of Janus kinase 2 inhibitor therapy for patients with myeloproliferative neoplasms.

    PubMed

    Quintás-Cardama, Alfonso; Verstovsek, Srdan

    2012-02-15

    The myeloproliferative neoplasms (MPNs) essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (MF) are malignancies that frequently harbor the recurrent somatic point mutation JAK2(V617F). The discovery of this mutation has fueled the development of Janus kinase 2 (JAK2) inhibitors. Available results have indicated that JAK2 inhibitors are particularly effective at reducing spleen size. However, the activity of these agents is multifaceted and also involves a marked improvement of systemic symptoms and, for those agents with dual JAK1 and JAK2 inhibitory activity, a marked reduction in the levels of circulating cytokines involved in the pathogenesis of the disease. Because JAK2 inhibitors are not specific for JAK2(V617F), responses have also been observed in JAK2(V617F) -negative MPNs because of the inhibition of wild-type JAK2, which is also likely responsible for the induction of cytopenias in patients with MF and for the normalization of peripheral blood counts observed in patients with ET or PV. Given the distinct mortality and morbidity associated with ET, PV, and MF, the use of JAK2 inhibitors appears reasonable for patients with MF as well as for those with ET or PV who have become resistant or intolerant to hydroxyurea. Ongoing randomized, placebo-controlled, phase 3 trials will further delineate the role of these agents in the management of patients with MPNs. The pros and cons of JAK2 kinase inhibitor therapy are herein discussed. PMID:21766300

  2. Pro/con clinical debate: Is high-volume hemofiltration beneficial in the treatment of septic shock?

    PubMed Central

    Reiter, Karl; Bellomo, Rinaldo; Ronco, Claudio; Kellum, John A

    2002-01-01

    Although there have been exciting advances in the management of sepsis and septic shock, mortality still remains high. Recent data suggest that high-volume hemofiltration (HVHF) may play a role in these patients. In contrast to the usual rate of hemofiltration, HVHF is felt to be better able to remove the inflammatory mediators associated with sepsis and septic shock. Such an approach is currently incapable of selectively removing specific mediators. This may be a problem when one considers that several mediators may in fact be beneficial. When determining whether HVHF should be instituted in a patient with septic shock, one need remember that its role is far from clear and its usefulness remains the subject of much debate. Although early data is encouraging, it is clear that additional data is required before HVHF becomes standard management. The authors of this pro/con debate, which is based on a clinical scenario, first describe their own position and then respond to their opponent's position. PMID:11940261

  3. Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps), Version 2.0

    NASA Technical Reports Server (NTRS)

    Baxley, Brian T.; Johnson, William C.; Swenson, Harry N.; Robinson, John E.; Prevot, Tom; Callantine, Todd J.; Scardina, John; Greene, Michael

    2013-01-01

    This document is an update to the operations and procedures envisioned for NASA s Air Traffic Management (ATM) Technology Demonstration #1 (ATD-1). The ATD-1 Concept of Operations (ConOps) integrates three NASA technologies to achieve high throughput, fuel-efficient arrival operations into busy terminal airspace. They are Traffic Management Advisor with Terminal Metering (TMA-TM) for precise time-based schedules to the runway and points within the terminal area, Controller-Managed Spacing (CMS) decision support tools for terminal controllers to better manage aircraft delay using speed control, and Flight deck Interval Management (FIM) avionics and flight crew procedures to conduct airborne spacing operations. The ATD-1 concept provides de-conflicted and efficient operations of multiple arrival streams of aircraft, passing through multiple merge points, from top-of-descent (TOD) to the Final Approach Fix. These arrival streams are Optimized Profile Descents (OPDs) from en route altitude to the runway, using primarily speed control to maintain separation and schedule. The ATD-1 project is currently addressing the challenges of integrating the three technologies, and their implantation into an operational environment. The ATD-1 goals include increasing the throughput of high-density airports, reducing controller workload, increasing efficiency of arrival operations and the frequency of trajectory-based operations, and promoting aircraft ADS-B equipage.

  4. Status and Progress of a Fault Current Limiting Hts Cable to BE Installed in the con EDISON Grid

    NASA Astrophysics Data System (ADS)

    Maguire, J.; Folts, D.; Yuan, J.; Henderson, N.; Lindsay, D.; Knoll, D.; Rey, C.; Duckworth, R.; Gouge, M.; Wolff, Z.; Kurtz, S.

    2010-04-01

    In the last decade, significant advances in the performance of second generation (2G) high temperature superconducting wire have made it suitable for commercially viable applications such as electric power cables and fault current limiters. Currently, the U.S. Department of Homeland Security is co-funding the design, development and demonstration of an inherently fault current limiting HTS cable under the Hydra project with American Superconductor and Consolidated Edison. The cable will be approximately 300 m long and is being designed to carry 96 MVA at a distribution level voltage of 13.8 kV. The underground cable will be installed and energized in New York City. The project is led by American Superconductor teamed with Con Edison, Ultera (Southwire and nkt cables joint venture), and Air Liquide. This paper describes the general goals, design criteria, status and progress of the project. Fault current limiting has already been demonstrated in 3 m prototype cables, and test results on a 25 m three-phase cable will be presented. An overview of the concept of a fault current limiting cable and the system advantages of this unique type of cable will be described.

  5. 40 CFR 60.213 - Monitoring of operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... daily record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  6. 40 CFR 60.233 - Monitoring of operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  7. 40 CFR 60.233 - Monitoring of operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  8. 40 CFR 60.233 - Monitoring of operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  9. 40 CFR 60.233 - Monitoring of operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  10. 40 CFR 63.625 - Monitoring requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... determine and permanently record the mass flow of phosphorus-bearing feed material to the process. The... P2O5 feed by first determining the total mass rate in metric ton/hour of phosphorus bearing feed...

  11. 40 CFR 60.213 - Monitoring of operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... daily record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  12. 40 CFR 60.213 - Monitoring of operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... daily record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  13. 40 CFR 60.213 - Monitoring of operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... daily record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  14. 40 CFR 60.233 - Monitoring of operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  15. 40 CFR 60.213 - Monitoring of operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., maintain, and operate a flow monitoring device which can be used to determine the mass flow of phosphorus... daily record of equivalent P2O5 feed by first determining the total mass rate in Mg/hr of...

  16. 40 CFR 63.625 - Monitoring requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... determine and permanently record the mass flow of phosphorus-bearing feed material to the process. The... P2O5 feed by first determining the total mass rate in metric ton/hour of phosphorus bearing feed...

  17. 40 CFR 63.625 - Monitoring requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... determine and permanently record the mass flow of phosphorus-bearing feed material to the process. The... P2O5 feed by first determining the total mass rate in metric ton/hour of phosphorus bearing feed...

  18. Role of fadR and atoC(Con) mutations in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesis in recombinant pha+ Escherichia coli.

    PubMed

    Rhie, H G; Dennis, D

    1995-07-01

    Recombinant Escherichia coli fadR atoC(Con) mutants containing the polyhydroxyalkanoate (PHA) biosynthesis genes from Alcaligenes eutrophus are able to incorporate significant levels of 3-hydroxyvalerate (3HV) into the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)]. We have used E. coli fadR (FadR is a negative regulator of fatty acid oxidation) and E. coli atoC(Con) (AtoC is a positive regulator of fatty acid uptake) mutants to demonstrate that either one of these mutations alone can facilitate copolymer synthesis but that 3HV levels in single mutant strains are much lower than in the fadR atoC(Con) strain. E. coli atoC(Con) mutants were used alone and in conjunction with atoA and atoD mutants to determine that the function of the atoC(Con) mutation is to increase the uptake of propionate and that this uptake is mediated, at least in part, by atoD+. Similarly, E. coli fadR mutants were used alone and in conjunction with fadA, fadB, and fadL mutants to show that the effect of the fadR mutation is dependent on fadB+ and fadA+ gene products. Strains that were mutant in the fadB or fadA locus were unable to complement a PHA biosynthesis pathway that was mutant at the phaA locus (thiolase), but a strain containing a fadR mutation and which was fadA+ fadB+ was able to complement the phaA mutation and incorporated 3HV into P(3HB-co-3HV) to a level of 29 mol%. PMID:7618860

  19. Fotodensitometro realizzato con microscopio.

    NASA Astrophysics Data System (ADS)

    di Giovanni, G.

    1989-02-01

    This work describes the chracteristics and use of a microphotometer suitable for the measure of photographic density of photos of stars. The optics is a normal microscope which projects the small photographic image of a star on the plate of a photodiode. This high sensitivity instrument is easy to build up.

  20. EthicsConRep

    Cancer.gov

    The authors also gratefully acknowledge the copy editing assistance of Leslie Alter, MPH and Steve Brown. The Ethical Force Program’s initiative on patient-centered communication is funded in part by the American Medical Association Foundation, The California Endowment, the Commonwealth Fund and the Connecticut Health Foundation.

  1. The Classics, Con Brio

    ERIC Educational Resources Information Center

    Hansen, James

    1978-01-01

    Sponsored by a consortium of 30 American universities, Rome's Intercollegiate Center for Classical Studies offers a year of study to American undergraduate classics majors. Instructors are also American and normally stay only a year; teaching assistants are always ex-students of the center. Extensive field trips are an important part of the…

  2. [Weighing pros and cons].

    PubMed

    de Wit, W

    1992-03-15

    An adequate, high-quality animal health service is indispensable to animal production in the Netherlands. Modern intensive animal husbandry, with its high density of animals, needs a considerable input of knowledge, vaccines and drugs. The consumer expects healthy and especially safe products. These two goals are in seeming contradiction. Moreover, veterinary help, the necessary use of drugs, the supervision and control of AID (Agricultural Inspection Services) and RVV (Inspection Service for Meat and Meat Products) add to the already substantial costs of modern animal husbandry. From the point of view of integral quality control, the question is what changes are necessary to achieve a more effective health service. Goals for the future include: reducing the structural dependence on drugs and additives; substantially reducing the number of active substances used; increasing consumer confidence in animal products. PMID:1549832

  3. Neo-Conned University

    ERIC Educational Resources Information Center

    Jones, Andee

    2014-01-01

    Censorship, says Australian political theorist John Keane (1991), can "echo within us, take up residence within ourselves, spying on us, a private amanuensis who reminds us never to go too far... It makes us zip our lips, tremble and think twice" (p. 39). It can also make us sick. The author states that this is her argument here: that,…

  4. 40 CFR 60.242 - Standard for fluorides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... atmosphere from any affected facility any gases which contain total fluorides in excess of 0.25 g/hr/megagram (Mg) of equivalent P2O5 stored (5.0 × 10 −4 lb/hr/ton of equivalent P2O5 stored). (b) No owner or... Industry: Granular Triple Superphosphate Storage Facilities § 60.242 Standard for fluorides. (a) On...

  5. 40 CFR 60.242 - Standard for fluorides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... atmosphere from any affected facility any gases which contain total fluorides in excess of 0.25 g/hr/megagram (Mg) of equivalent P2O5 stored (5.0 × 10 −4 lb/hr/ton of equivalent P2O5 stored). (b) No owner or... Industry: Granular Triple Superphosphate Storage Facilities § 60.242 Standard for fluorides. (a) On...

  6. 40 CFR 60.242 - Standard for fluorides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... atmosphere from any affected facility any gases which contain total fluorides in excess of 0.25 g/hr/megagram (Mg) of equivalent P2O5 stored (5.0 × 10 −4 lb/hr/ton of equivalent P2O5 stored). (b) No owner or... Industry: Granular Triple Superphosphate Storage Facilities § 60.242 Standard for fluorides. (a) On...

  7. 40 CFR 60.242 - Standard for fluorides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... atmosphere from any affected facility any gases which contain total fluorides in excess of 0.25 g/hr/megagram (Mg) of equivalent P2O5 stored (5.0 × 10 −4 lb/hr/ton of equivalent P2O5 stored). (b) No owner or... Industry: Granular Triple Superphosphate Storage Facilities § 60.242 Standard for fluorides. (a) On...

  8. 40 CFR 60.242 - Standard for fluorides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... atmosphere from any affected facility any gases which contain total fluorides in excess of 0.25 g/hr/megagram (Mg) of equivalent P2O5 stored (5.0 × 10 −4 lb/hr/ton of equivalent P2O5 stored). (b) No owner or... Industry: Granular Triple Superphosphate Storage Facilities § 60.242 Standard for fluorides. (a) On...

  9. 40 CFR 60.234 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .../Mg (lb/ton) of equivalent P2O5 feed. Csi=concentration of total fluorides from emission point “i,” mg...=number of emission points in the affected facility. P=equivalent P2O5 feed rate, Mg/hr (ton/hr). K=conversion factor, 1000 mg/g (7,000 gr/lb). (2) Method 13A or 13b shall be used to determine the...

  10. 40 CFR 60.234 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .../Mg (lb/ton) of equivalent P2O5 feed. Csi=concentration of total fluorides from emission point “i,” mg...=number of emission points in the affected facility. P=equivalent P2O5 feed rate, Mg/hr (ton/hr). K=conversion factor, 1000 mg/g (7,000 gr/lb). (2) Method 13A or 13b shall be used to determine the...

  11. Phosphate-based glasses: Prediction of acoustical properties

    NASA Astrophysics Data System (ADS)

    El-Moneim, Amin Abd

    2016-04-01

    In this work, a comprehensive study has been carried out to predict the composition dependence of bulk modulus and ultrasonic attenuation coefficient in the phosphate-based glass systems PbO-P2O5, Li2O-TeO2-B2O3-P2O5, TiO2-Na2O-CaO-P2O5 and Cr2O3-doped Na2O-ZnO-P2O5 at room temperature. The prediction is based on (i) Makishima-Mackenzie theory, which correlates the bulk modulus with packing density and dissociation energy per unit volume, and (ii) Our recently presented semi-empirical formulas, which correlate the ultrasonic attenuation coefficient with the oxygen density, mean atomic ring size, first-order stretching force constant and experimental bulk modulus. Results revealed that our recently presented semi-empirical formulas can be applied successfully to predict changes of ultrasonic attenuation coefficient in binary PbO-P2O5 glasses at 10 MHz frequency and in quaternary Li2O-TeO2-B2O3-P2O5, TiO2-Na2O-CaO-P2O5 and Cr2O3-Na2O-ZnO-P2O5 glasses at 5 MHz frequency. Also, Makishima-Mackenzie theory appears to be valid for the studied glasses if the effect of the basic structural units that present in the glass network is taken into account.

  12. Concepciones Alternativas de "Fotosintesis" en estudiantes Universitarios del curso basico de Biologia y posibles correcciones con el Modelo Educativo MODEF

    NASA Astrophysics Data System (ADS)

    De Jesus Roman, Sandra

    Concepciones Alternativas de Fotosíntesis en estudiantes Universitariosdel curso básico de Biología y posibles correcciones con el Modelo Educativo MODEF El modelo educativo para la enseñanza de Fotosíntesis (MODEF) se implantó para trabajar el problema de las concepciones alternativas (CA) en un curso de Biología General. Se evaluaron los resultados en cuanto al logro del aprendizaje significativo. La pregunta central de la investigación fue: ¿Cómo aporta el modelo educativo en la didáctica y comprensión del tema de fotosíntesis? Se efectuó una investigación acción con una fase cuantitativa y una cualitativa. Para la fase cuantitativa se elaboró una prueba para determinar las concepciones alternativas, se validó y se sometió a los estudiantes que participaron en el estudio antes y después de ofrecer la unidad de metabolismo celular. Los participantes eran estudiantes de primer año de la Universidad de Puerto Rico en Bayamón (UPRB). Se llevó a cabo un análisis de consistencia interna de la prueba mediante el método Alfa de Cronbach. Se analizaron las contestaciones a cada pregunta mediante la prueba de Ji cuadrado de contingencia, se efectuó la prueba de t y el coeficiente r de Pearson. La fase cualitativa incluyó la observación participativa de la investigadora- profesora, las reflexiones de los estudiantes y la información de las entrevistas semi-estructuradas que se realizaron a tres estudiantes del curso. El análisis se llevó a cabo mediante el Modelo de Wolcott. Se trabajaron diez CA de las cuales siete fueron corregidas mediante el Modelo MODEF. Las actividades más importantes para el proceso de aprendizaje incluyeron el trabajo de investigación o búsqueda de información para hacer una presentación digital, la elaboración de tablas, los mapas de conceptos, el uso de visuales o videos y las analogías para explicar conceptos o procesos. En conclusión: se recomienda el uso del Modelo MODEF para la discusión del tema de Fotosíntesis a base de los resultados cuantitativos y cualitativos de esta investigación. El Comité Institucional para la Protección de los Seres Humanos en la Investigación (CIPSHI) autorizó el estudio.

  13. Loss of L-PHA-, PNA-, or ConA-reactive oligosaccharides is associated with a poor prognosis in human Burkitt's lymphoma.

    PubMed

    Suzuki, Osamu; Nozawa, Yoshihiro; Abe, Masafumi

    2007-04-01

    The expression of cell surface oligosaccharides is associated with various biological phenomena. To clarify the relationship between lectin binding and the survival of patients with Burkitt's lymphoma, tumor samples from nine patients with Burkitt's lymphoma were analyzed by lectin histochemistry. Kaplan-Meier analysis showed that survival is significantly shorter for patients with negative reactivity for lectins from Phaseolus vulgaris (L-PHA), Arachis hypogaea (PNA), or Canavalia ensiformis (ConA) than for those with positive reactivity for these lectins. Immunohistochemistry for N-acetylglucosaminyltransferase V, which synthesizes beta1,6-branched oligosaccharides such as L-PHA-reactive oligosaccharides, was positive in 8 of 9 patients, but there was no correlation between its expression and that of L-PHA-reactive oligosaccharides. Collectively, a loss of L-PHA-, PNA-, or ConA-reactive oligosaccharides is closely associated with a poor prognosis in patients with Burkitt's lymphoma. PMID:17342314

  14. A methodological approach to comparing pros and cons of delocalizing villages: socio-economic and technical issues

    NASA Astrophysics Data System (ADS)

    Guadagno, Eleonora; Iovine, Giulio G. R.; Petrucci, Olga; Forciniti, Pinuccia R.

    2014-05-01

    On 7th March 2005, prolonged rainfalls combined with snowfalls activated a wide complex rock slide-earth flow that partly destroyed the village of Cavallerizzo at Cerzeto (Calabria, Southern Italy). Superposed tectonic units made of Palaeozoic metamorphic rocks, overlain by Miocene-Quaternary clastic terrains, crop out in the study area. The main scarp of the landslide developed by a recent normal fault, striking N-S along the western margin of the Crati graben and extended ca. 25 km. In its lower part, the phenomenon evolved in two main earth-flow bodies that extended along minor drainages and then merged along the S. Nicola torrent. The sector affected by the instability actually belongs to a large-scale slope movement: the 2005 activation was in fact only a paroxysmal episode of a long history of slope deformations, noticed in the area since the XVIII century. Warning signs had been recorded for weeks before the collapse, and the threatened area had been put under monitoring by CNR-IRPI. When the movement accelerated, people had already been alerted and evacuated (329 out of 581 inhabitants of Cerzeto were sheltered in nearby villages), thus neither victims nor injured were recorded. As a whole, 124 buildings were severely damaged or destroyed, the main road was interrupted. Immediately after the 7th March 2005 event, the national Department for Civil Protection decided to evaluate the feasibility of delocalizing Cavallerizzo to another site. At this purpose, CNR-IRPI was asked to analysing the "geological suitability" of 3 different sites (Pianette, Amatine, and Colombra), pre-selected by the same Municipality of Cerzeto in accordance to the Civil Protection; the results of the study were completed in early Summer 2005. Between October 2007 and December 2011, a new settlement was realized by the Italian Government, and the houses were delivered to people once living at Cavallerizzo. In the last years, the socio-economic effects of the delocalization of Cavallerizzo have been analysed within the frame of a PhD thesis by one of the authors. The present study focuses on the Cavallerizzo case study to discuss a methodological approach useful to comparing pros and cons of delocalizing villages, aiming at properly considering socio-economic effects in addition to technical issues.

  15. Emerging and Legacy Contaminants in The Foodweb in The Lower Columbia River: USGS ConHab Project

    NASA Astrophysics Data System (ADS)

    Nilsen, E. B.; Alvarez, D.; Counihan, T.; Elias, E.; Gelfenbaum, G. R.; Hardiman, J.; Jenkins, J.; Mesa, M.; Morace, J.; Patino, R.; Torres, L.; Waite, I.; Zaugg, S.

    2012-12-01

    An interdisciplinary study, USGS Columbia River Contaminants and Habitat Characterization (ConHab) project, investigates transport pathways, chemical fate, and effects of polybrominated diphenyl ethers (PBDEs) and other endocrine disrupting chemicals (EDCs) in aquatic media and the foodweb in the lower Columbia River, Oregon and Washington. Polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were co-deployed at each of 10 sites in 2008 to provide a measure of the dissolved concentrations of select PBDEs, chlorinated pesticides, and other EDCs. PBDE-47 was the most prevalent of the PBDEs detected. Numerous organochlorine pesticides, both banned and current-use, including hexachlorobenzene, pentachloroanisole, dichlorodiphenyltrichloroethane (DDT) and its degradates, chlorpyrifos, endosulfan, and the endosulfan degradation products, were measured at each site. EDCs commonly detected included a series of polycyclic aromatic hydrocarbons (PAHs), fragrances (galaxolide), pesticides (chlorpyrifos and atrazine), plasticizers (phthalates), and flame retardants (phosphates). The downstream sites tended to have the highest concentrations of contaminants in the lower Columbia River. In 2009 and 2010 passive samplers were deployed and resident largescale suckers (Catostomus macrocheilus) and surface bed sediments were collected at three of the original sites representing a gradient of exposure based on 2008 results. Brain, fillet, liver, stomach, and gonad tissues were analyzed. Chemical concentrations were highest in livers, followed by brain, stomach, gonad, and, lastly, fillet. Concentrations of halogenated compounds in tissue samples ranged from <1 to 400 ng g-1 wet tissue. PBDEs, organochlorine pesticides, DDT and its degradates, and polychlorinated biphenyls (PCBs) were detected at all sites in nearly all organs tested. PBDE congeners most frequently detected and at the highest concentrations were PBDE-47 > PBDE-100 > PBDE-154 > PBDE-153. Concentrations in tissues and in sediments increased moving downstream from Skamania, WA to Columbia City, OR to Longview, WA. Preliminary biomarker results indicate that fish at the downstream sites experience greater stress relative to the upstream site based on gonad, kidney, spleen, and liver histopathology. These results support the hypothesis that contaminant concentrations in the environment correlate to bioaccumulation in the foodweb.

  16. Flight Deck Surface Trajectory-based Operations (STBO): Results of Piloted Simulations and Implications for Concepts of Operation (ConOps)

    NASA Technical Reports Server (NTRS)

    Foyle, David C.; Hooey, Becky L.; Bakowski, Deborah L.

    2013-01-01

    The results offour piloted medium-fidelity simulations investigating flight deck surface trajectory-based operations (STBO) will be reviewed. In these flight deck STBO simulations, commercial transport pilots were given taxi clearances with time and/or speed components and required to taxi to the departing runway or an intermediate traffic intersection. Under a variety of concept of operations (ConOps) and flight deck information conditions, pilots' ability to taxi in compliance with the required time of arrival (RTA) at the designated airport location was measured. ConOps and flight deck information conditions explored included: Availability of taxi clearance speed and elapsed time information; Intermediate RTAs at intermediate time constraint points (e.g., intersection traffic flow points); STBO taxi clearances via ATC voice speed commands or datal ink; and, Availability of flight deck display algorithms to reduce STBO RTA error. Flight Deck Implications. Pilot RTA conformance for STBO clearances, in the form of ATC taxi clearances with associated speed requirements, was found to be relatively poor, unless the pilot is required to follow a precise speed and acceleration/deceleration profile. However, following such a precise speed profile results in inordinate head-down tracking of current ground speed, leading to potentially unsafe operations. Mitigating these results, and providing good taxi RTA performance without the associated safety issues, is a flight deck avionics or electronic flight bag (EFB) solution. Such a solution enables pilots to meet the taxi route RTA without moment-by-moment tracking of ground speed. An avionics or EFB "error-nulling" algorithm allows the pilot to view the STBO information when the pilot determines it is necessary and when workload alloys, thus enabling the pilot to spread his/her attention appropriately and strategically on aircraft separation airport navigation, and the many other flight deck tasks concurrently required. Surface Traffic Management (STM) System Implications. The data indicate a number of implications regarding specific parameters for ATC/STM algorithm development. Pilots have a tendency to arrive at RTA points early with slow required speeds, on time for moderate speeds, and late with faster required speeds. This implies that ATC/STM algorithms should operate with middle-range speeds, similar to that of non-STBO taxi performance. Route length has a related effect: Long taxi routes increase the earliness with slow speeds and the lateness with faster speeds. This is likely due to the" open-loop" nature of the task in which the speed error compounds over a longer time with longer routes. Results showed that this may be mitigated by imposing a small number oftime constraint points each with their own RTAs effectively tuming a long route into a series of shorter routes - and thus improving RTA performance. STBO ConOps Implications. Most important is the impact that these data have for NextGen STM system ConOps development. The results of these experiments imply that it is not reasonable to expect pilots to taxi under a "Full STBO" ConOps in which pilots are expected to be at a predictable (x,y) airport location for every time (t). An STBO ConOps with a small number of intermediate time constraint points and the departing runway, however, is feasible, but only with flight deck equipage enabling the use of a display similar to the "error-nulling algorithm/display" tested.

  17. Potential pros and cons of external healthcare performance evaluation systems: real-life perspectives on Iranian hospital evaluation and accreditation program

    PubMed Central

    Jaafaripooyan, Ebrahim

    2014-01-01

    Background: Performance evaluation is essential to quality improvement in healthcare. The current study has identified the potential pros and cons of external healthcare evaluation programs, utilizing them subsequently to look into the merits of a similar case in a developing country. Methods: A mixed method study employing both qualitative and quantitative data collection and analysis techniques was adopted to achieve the study end. Subject Matter Experts (SMEs) and professionals were approached for two-stage process of data collection. Results: Potential advantages included greater attractiveness of high accreditation rank healthcare organizations to their customers/purchasers and boosted morale of their personnel. Downsides, as such, comprised the programs’ over-reliance on value judgment of surveyors, routinization and incurring undue cost on the organizations. In addition, the improved, standardized care processes as well as the judgmental nature of program survey were associated, as pros and cons, to the program investigated by the professionals. Conclusion: Besides rendering a tentative assessment of Iranian hospital evaluation program, the study provides those running external performance evaluations with a lens to scrutinize the virtues of their own evaluation systems through identifying the potential advantages and drawbacks of such programs. Moreover, the approach followed could be utilized for performance assessment of similar evaluation programs. PMID:25279381

  18. Multi-mannosides based on a carbohydrate scaffold: synthesis, force field development, molecular dynamics studies, and binding affinities for lectin Con A.

    PubMed

    Gouin, Sébastien G; Vanquelef, Enguerran; Fernandez, José Manuel García; Mellet, Carmen Ortiz; Dupradeau, François-Yves; Kovensky, José

    2007-11-23

    A short and efficient strategy for the synthesis of multi-valent mannosides based on a selectively functionalized carbohydrate scaffold was reported involving (i) direct regioselective azidation of unprotected commercial saccharides, (ii) acetylation, (iii) grafting of the mannosyl ligands by click chemistry, and (iv) deacetylation. New glycoclusters with a valency ranging from 1 to 4 and different spatial arrangements of the epitopes were obtained. Binding affinities of the new glycoclusters toward concanavalin A (Con A) lectin were investigated by an enzyme-linked lectin essay (ELLA). The synthetic multi-valent compounds exhibited a remarkable cluster effect with a relative potency per mannoside residue ranging from 8.1 to 9.1 depending on the structures. ELLA experiments were in agreement with the establishment of favorable interactions between triazole ring and Con A, increasing the binding affinity. A new force field topology database was developed in agreement with the GLYCAM 2004 force field. Molecular dynamics performed on representative glyco-conjugates revealed interesting structural features such as rigidity of the scaffold for a well-defined presentation of the ligands and highly flexible mannose counterparts. The new glycoconjugates reported may be promising tools as probes or effectors of biological processes involving lectins. PMID:17979282

  19. FACTORES SOCIO-ESTRUCTURALES Y EL ESTIGMA HACIA EL VIH/SIDA: EXPERIENCIAS DE PUERTORRIQUEÑOS/AS CON VIH/SIDA AL ACCEDER SERVICIOS DE SALUD

    PubMed Central

    RIVERA-DIAZ, MARINILDA; VARAS-DIAZ, NELSON; REYES-ESTRADA, MARCOS; SURO, BEATRIZ; CORIANO, DORALIS

    2013-01-01

    RESUMEN El estigma relacionado al VIH/SIDA continúa afectando la prestación de servicios de salud y el bienestar físico y mental de las personas con VIH/SIDA (PVS). Recientemente la literatura científica ha señalado la importancia de comprender las manifestaciones de estigma más allá de las interacciones individuales. Por tal razón, investigaciones recientes en y fuera de Puerto Rico enfatizan la importancia de entender cómo factores socio-estructurales (FSE) influyen en los procesos de estigmatización social. Con el propósito de examinar los FSE que influyen en las manifestaciones de estigma relacionado al VIH/SIDA, realizamos y analizamos nueve grupos focales compuestos por hombres y mujeres en tratamiento para el VIH/SIDA que habían tenido experiencias estigmatizantes. Los participantes identificaron FSE relacionados a las manifestaciones de estigma, tales como el uso de viviendas especializadas, descentralización de los servicios de salud y el desarrollo de protocolos administrativos excluyentes en los servicios de salud. Los resultados demuestran la importancia de considerar los FSE en el desarrollo e implementación de intervenciones dirigidas a la población. PMID:24639599

  20. Glass transition temperature and conductivity in Li2O and Na2O doped borophosphate glasses

    NASA Astrophysics Data System (ADS)

    Ashwajeet, J. S.; Sankarappa, T.; Ramanna, R.; Sujatha, T.; Awasthi, A. M.

    2015-08-01

    Two alkali doped Borophosphate glasses in the composition, (B2O3)0.2. (P2O5)0.3. (Na2O)(0.5-x). (Li2O)x, where x = 0.05 to 0.50 were prepared by standard melt quenching method at 1200K. Non-crystalline nature was confirmed by XRD studies. Room temperature density was measured by Archimedes principle. DC conductivity in the temperature range from 300K to 575K has been measured. Samples were DSC studied in the temperature range from 423K to 673K and glass transition temperature was determined. Glass transition temperature passed through minima for Li2O con.2centration between 0.25 and 0.30 mole fractions. Activation energy of conduction has been determined by analyzing temperature variation of conductivity determining Arrhenius law. Conductivity passed through minimum and activation passed through maximum for Li2O content from 0.25 to 0.30 mole fractions. Glass transition temperature passed through minimum for the same range of Li2O content. These results revealed mixed alkali effect taking place in these glasses. It is for the first time borophosphate glasses doped with Li2O and Na2O have been studied for density and dc conductivity and, the mixed alkali effect (MAE) has been observed.

  1. Conversation with Lara about the Earth and Land. (Spanish Title: Conversando con Lara sobre la Tierra y la Teirra.) Conversando com Lara sobre a Terra e a Terra

    NASA Astrophysics Data System (ADS)

    da Conceição Barbosa-Lima, Maria

    2010-12-01

    The present article is the analysis of a conversation between the author and Lara, a four-yearold- girl, enrolled in nursery school, while she makes a drawing of the Earth. It took place outside school environment and without any other person around to avoid interference during the interview. According to Ferreira & Silva (2004), a researcher can only comprehend a child's drawing, or form, by listening to him/her while he/she is creating it. Lara presented the traditional flat drawing, picturing the sky parallel to the ground, as reported by Nardi & Carvalho (1996). However, when asked to draw the World - term used by Butterworth et al. (2002), in order to avoid unnecessary confusion - she represented it by a circle, with herself on the surface. Her drawings led to the conclusion that such girl does not know yet the World in which she lives is the Earth, and probably because of that, within her age and consequent maturity, she accurately differentiates the concepts of land and Earth. El presente artículo analiza una entrevista libre, mientras una niña de 4 años y 4 meses, matriculada en el pregrado, dibuja la Tierra. Esta entrevista se realizó fuera del ambiente escolar y sin otra persona alrededor que pudiera interferir. De acuerdo con Ferreira Silva (2004), para quien investiga es posible conocer realmente lo que un niño o una niña pone en el papel a través de grafismos y/o dibujos si se lo escucha durante el proceso de creación de la escritura con imágenes. La niña, en este caso, representa la Tierra con el tradicional dibujo plano y el "cielo" paralelo al suelo, conforme analizaron Nardi & Carvalho (1996). Pero, cuando se Le solicita dibujar el "Mundo" - palabra empleada en un trabajo de Butterworth et al. (2002), con intención de no provocar "confusiones" innecesarias a sus sujetos de investigación- lo representa de forma circular, poniéndose sobre su superficie. Sus dibujos llevan a concluir que esta niña aún no tiene conocimiento que el mundo en que vive es el planeta Tierra y que, probablemente por ese motivo, distingue con precisión, dentro de los limites de comprensión de la edad y madurez asociada, la tierra y la Tierra. O presente artigo analisa uma entrevista livre enquanto uma menina de quatro anos e quatro meses, matriculada na educação infantil, desenhava a Terra. A entrevista se realizou fora do ambiente escolar e sem qualquer outra pessoa por perto que pudesse interferir. De acordo com Ferreira & Silva (2004), para que o pesquisador conheça realmente o que uma criança põe no papel através de grafismos e/ou desenhos, é necessário ouvi-la durante o processo de criação do desenho. A menina apresenta, em relação à Terra, o tradicional desenho plano com o 'céu' paralelo ao solo, conforme já apresentaram Nardi & Carvalho (1996). Mas quando solicitada a desenhar o Mundo - palavra empregada em um trabalho por Butterworth et al. (2002), com intenção de não provocar 'confusões' desnecessárias para seus pesquisados - o representa de forma circular, colocando-se sobre sua superfície. Seus desenhos levaram à conclusão que esta criança ainda não tem conhecimento de que o Mundo em que vive é o Planeta Terra e que, provavelmente por este motivo, diferencia com precisão, dentro dos limites impostos por sua idade e consequente maturidade, a terra e a Terra.

  2. Ontogeny of con A and PHA responses of chicken blood cells in MHC-compatible lines 6(3) and 7(2).

    PubMed

    Fredericksen, T L; Gilmour, D G

    1983-06-01

    The development of T cell responsiveness to Con A and PHA was examined in two MHC-compatible inbred chicken lines, RPRL 6(3) and 7(2), at ages 2 to 118 days posthatching. These lines are respectively resistant or susceptible to Marek's disease, a naturally occurring, virally induced T cell lymphoma. Between-line comparisons were made of optimal in vitro responses of diluted serum-free blood cells to each mitogen in two groups of chicks tested over ages 2 to 63 and 41 to 118 days. Over 2 to 63 days, Con A responses increased with age at the same rate in each line, but 7(2) responses averaged 2.3 times higher than 6(3). The increase with age was dependent on blood lymphocyte counts, which also increased with age in parallel in both lines. In contrast, the between-line difference in responsiveness was dependent on intrinsic reactivity of cells as well as lymphocyte counts. Covariance analysis was used to estimate that line 7(2) was 1.4 times higher than 6(3) in intrinsic cell reactivity, after accounting for the effect of the twofold higher blood lymphocyte counts in 7(2), and that this intrinsic difference contributed almost one-half the total difference. Over 41 to 118 days Con A responses no longer increased with age, although lymphocyte counts were still increasing, and the line difference (2.6 times) was now almost entirely contributed by a 2.3-fold superiority of 7(2) blood cells in intrinsic reactivity. The line difference in PHA responses was the reverse of the above in young chicks, with 6(3) responses greater than 7(2) in spite of lower lymphocyte counts. In additional chicks tested over 5 to 26 days, intrinsic reactivity of 6(3) cells to PHA averaged 4.5 times higher than 7(2). There was an abrupt decline in intrinsic reactivity of line 6(3) blood cells between 26 and 41 days to a level equal with 7(2). After this age, line 7(2) responses were 1.8 times greater than those of 6(3), and this difference was dependent solely on lymphocyte count differences. The results suggest that different gene systems mediate blood cell responses to PHA as compared with Con A. The pattern of developmental differences between inbred lines indicates the existence of distinct or partly overlapping T cell subsets with different reactivities to PHA or Con A, and of higher suppressor activity of adherent cells in line 6(3) blood. Both these differences may be related to line 6(3) inherited resistance to Marek's disease. PMID:6854015

  3. Investigation on the thermal properties, density and degradation of quaternary iron and titanium phosphate based glasses

    NASA Astrophysics Data System (ADS)

    Shaharuddin, SIS; Ahmed, I.; Furniss, D.; Parsons, AJ; Rudd, CD

    2016-02-01

    The possibility of producing phosphate based glasses (PBG) with tailored degradation profile allows for unique utilisation in biomedical application. Various compositions in the phosphate based glass (PBG) system of (50-x)P2O5-40Ca-(5+x)Na-5TiO2 and (50-x)P2O5-40Ca- (5+x)Na-5Fe2O3, where x= 5 and 10 were prepared and characterised. Method as differential scanning calorimetry (DSC) has been used to characterise the thermal properties of these phosphate based glasses. It was observed that both glass transition temperature (Tg) and onset of crystalisatisation temperature (Tx) increased with increasing phosphate content. In addition, Tg values were found to be higher for the P2O5-CaO-Na2O-TiO2 glass system compared to P2O5- CaO-Na2O-Fe2O3 glass system. The density result showed that increasing the P2O5 content at the expense Na2O led to a decrease in density for both glass systems. The dissolution study of these glasses was conducted in phosphate buffered saline (PBS). It was observed that the dissolution rate of P2O5-CaO-Na2O-Fe2O3 glass system was higher than the P2O5-CaO-Na2O-TiO2 glass system. The dissolution rate for both glass systems was in the order of 10-6 g cm-2 hr-1.

  4. The soil-water balance simulations of a grassland in response to CO2, rainfall, and biodiversity manipulations at BioCON

    NASA Astrophysics Data System (ADS)

    Flinker, R. H.; Cardenas, M.; Caldwell, T. G.; Rich, R.; Reich, P.

    2013-12-01

    The BioCON (Biodiversity, CO2 and N) experiment has been continuously running since 1997. Operated by the University of Minnesota and located within the Cedar Creek Ecosystem Science Reserve in Minnesota, USA, BioCON is a Free-Air CO2 Enrichment (FACE) experiment that investigates plant community response to three key environmental variables: nitrogen, atmospheric CO2 and biodiversity. More recently rainfall exclusion and temperature manipulation were added to the experiment which amounts to 371 plots. The site attempts to replicate predicted average temperature increases and a northern shift of plant species and any associated consequences. FACE experiments have been conducted for a number of years in different countries, but the focus has generally been on how plant communities, soil respiration and microbes respond. Minimal work has been focused on the hydrologic aspects of these experiments which are potentially valuable for investigating global warming effects on local and plot-scale ecohydrology. Thus, the objective of this work is to characterize and model unsaturated flow for different CO2 and rainfall treatments in order to see how they affect soil moisture dynamics and groundwater recharge on grasslands of central Minnesota. Our study focuses on simulating soil moisture dynamics in eighteen of the BioCON plots: six bare plots with regular rainfall regimes (zero plant species, three plots with elevated atmospheric CO2 levels), six regular rainfall regimes (nine plant species, three plots with elevated atmospheric CO2 levels) and six reduced rainfall regimes (nine plant species, three plots with elevated atmospheric CO2 levels). The Simultaneous Heat and Water (SHAW) model, which solves the Richards equation for unsaturated zone water flow coupled to a comprehensive energy balance model, was parameterized with a combination of field and lab estimates of soil properties. Field estimates of saturated hydraulic conductivity using tension infiltrometers ranged from 9.8 x 10-4 to 6.7 x 10-3 cm/s. Soil cores were collected and analyzed for soil hydraulic properties (texture, unsaturated hydraulic conductivity and moisture retention). From the grain size analyzes of soil samples collected every 10 cm until 1m depth, the soil is homogenous and on average 87% sand, 11% silt and 2% clay. We will be presenting results from the simulations and statistical comparisons to observations of soil moisture at four depths in each plot.

  5. Broadening, shifting, and line asymmetries in the 2<--0 band of CO and CO-N2: Experimental results and theoretical calculations

    NASA Astrophysics Data System (ADS)

    Predoi-Cross, Adriana; Bouanich, J. P.; Benner, D. Chris; May, A. D.; Drummond, J. R.

    2000-07-01

    We have measured the room temperature, widths, pressure shifts, and line asymmetry coefficients for many transitions of the first overtone band of CO and CO perturbed by N2. The broadening coefficients were obtained with an accuracy of about 1%. The pure CO profiles have been fitted by a Voigt profile while the CO-N2 spectral profiles have been fitted with a Lorentz and an empirical line shape model (HCv) that blends together a hard collision model and a speed-dependent Lorentz profile. In addition to the Voigt, Lorentz, and HCv models, we have added a dispersion profile to account for weak line mixing. The line broadening and shift coefficients are compared to semiclassical calculations employing a variety of intermolecular interactions. The line asymmetry results are compared to line mixing calculations based on the energy corrected sudden (ECS) model. The results indicate that effects other than line mixing also contribute to the measured line asymmetry.

  6. SUPPORT Tools for evidence-informed health Policymaking (STP) 16: Using research evidence in balancing the pros and cons of policies

    PubMed Central

    2009-01-01

    This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers. In this article, we address the use of evidence to inform judgements about the balance between the pros and cons of policy and programme options. We suggest five questions that can be considered when making these judgements. These are: 1. What are the options that are being compared? 2. What are the most important potential outcomes of the options being compared? 3. What is the best estimate of the impact of the options being compared for each important outcome? 4. How confident can policymakers and others be in the estimated impacts? 5. Is a formal economic model likely to facilitate decision making? PMID:20018106

  7. Errores sistemáticos del Catálogo Fundamental FK5, deducidos de las observaciones con Astrolabio Fotoeléctrico PAII, en el Hemisferio Sur

    NASA Astrophysics Data System (ADS)

    Manrique, W. T.; Podestá, R. C.; Alonso, E.; Actis, E. V.; Pacheco, A. M.; Bustos, G.; Lizhi, L.; Zezhi, W.; Fanmiao, Z.; Hongqi, W.; Perdomo, R.; González, A.; Gómez, G.

    Se dan los resultados obtenidos de los Errores Sistemáticos del Catálogo Fundamental FK5, Δ α δ, Δ α α, Δ δ α y Δ δ δ, derivados de las observaciones estelares con el Astrolabio Fotoeléctrico PAII del Observatorio de Beijing instalado en el Observatorio Astronómico ``Félix Aguilar'' de San Juan, de acuerdo al Proyecto de Colaboración entre los observatorios de San Juan, Beijing y La Plata. Se han usado los residuos seleccionados de 11000 estrellas aproximadamente, derivados de más de 400000 pasajes estelares en 1550 días, desde Febrero de 1992 a Marzo de 1997. La precisión media de los residuos es de 0,"043.

  8. Experience in managing a large-scale rescreening of Papanicolaou smears and the pros and cons of measuring proficiency with visual and written examinations.

    PubMed

    Rube, I F

    1989-01-01

    Experiences in a large-scale interlaboratory rescreening of Papanicolaou smears are detailed, and the pros and cons of measuring proficiency in cytology are discussed. Despite the additional work of the rescreening project and some psychological and technical problems, it proved to be a useful measure of the laboratory's performance as a whole. One problem to be avoided in future similar studies is the creation of too many diagnostic categories. Individual testing and certification have been shown to be accurate predictors of proficiency. For cytology, such tests require a strong visual component to test interpretation and judgment skills, such as by the use of glass slides or photomicrographs. The potential of interactive videodisc technology for facilitating cytopathologic teaching and assessment is discussed. PMID:2546349

  9. Estudio de NIH señala relación de la TC en la infancia con leucemia y cáncer de cerebro más tarde

    Cancer.gov

    Niños y adultos jóvenes a quienes se les hicieron exploraciones muchas veces con tomografía computarizada (TC), una herramienta de diagnóstico de uso frecuente, tienen un riesgo ligeramente mayor de padecer leucemia y tumores cerebrales en la década poste

  10. Human DNA polymerase alpha catalytic polypeptide binds ConA and RCA and contains a specific labile site in the N-terminus.

    PubMed Central

    Hsi, K L; Copeland, W C; Wang, T S

    1990-01-01

    The catalytic polypeptide of DNA polymerase alpha is often observed in vitro as a family of phosphopolypeptides predominantly of 180 and 165 kDa derived from a single primary structure. The estimated Mr of this polypeptide deduced from the full-length cDNA is 165 kDa. Immunoblot analysis with polyclonal antibodies against peptides of the N- and C-termini of the deduced primary sequence indicates that the observed family of polypeptides from 180 kDa to lower molecular weight results from proteolytic cleavage from the N-terminus. Antibodies against the N-terminal peptide detect only the 180 kDa species suggesting that this higher molecular weight polypeptide may be the result of posttranslational modification of the 165 kDa primary translation product. The catalytic polypeptide is not only phosphorylated but is also found to react with lectins ConA and RCA. N-terminal sequencing of the isolated catalytic polypeptide from human cells and of the recombinant fusion proteins indicates that the often observed 165 kDa polypeptide is the in vitro proteolytic cleavage product of the modified 180 kDa protein at the specific site between lys123 and lys124 within the sequence -RNVKKLAVTKPNN-. Images PMID:2243771

  11. Antiviral usage for H1N1 treatment: pros, cons and an argument for broader prescribing guidelines in the United States.

    PubMed

    Goldstein, Edward; Lipsitch, Marc

    2009-01-01

    Current CDC guidelines for antiviral treatment of people with influenza like illness (ILI) effectively discourage treatment of people with no underlying medical conditions unless they exhibit severe symptoms, such as evidence of lower respiratory tract infection or clinical deterioration. This guidance is unlike that provided by some other countries, which allow for treatment of most moderately symptomatic individuals. We examine evidence for benefits of antiviral usage for influenza treatment, including its relation to severe outcomes for the current pandemic H1N1 strain. We also discuss some of the potential cons of antiviral usage. In the current situation in the US, with an elevated and evidently growing burden of influenza hospitalizations and mortality, a high percentage of individuals infected with influenza (with almost all of those carrying the H1N1pdm strain) among those who exhibit ILI and get tested for influenza virus, very low levels of antiviral resistance and little time left for antiviral resistance to take off before large quantities of vaccine become available, we think it is worthwhile to consider a revision to the current antiviral usage recommendations, such that physicians would be encouraged to consider prescribing antivirals to individuals with moderate to severe symptoms who present for treatment.Note: Very recently CDC has adopted clarifications for its antiviral usage guidelines: http://www.cdc.gov/H1N1flu/antivirals/facts_clinicians.htm. PMID:20029660

  12. Biochar Usage: Pros and Cons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil fertility benefits of charcoal application have been reported as early as 1847 indicating that plant nutrients are sorbed within charcoal pores. The use of biomass-derived black carbon or biochar, the solid byproduct from the pyrolysis processing of any organic feedstock, has garnered recent a...

  13. Crossing the Rubric-Con

    ERIC Educational Resources Information Center

    Bailey, James R.

    2014-01-01

    This essay engages the prospect and peril of employing rubrics in America. It discusses how institutional independence affects the enterprise, and addresses whether rubrics will be received as salvation or subservience by educational agents. It asks how rubrics can benefit stakeholders while examining their unintended consequences. It concludes by…

  14. Crossing the Rubric-Con

    ERIC Educational Resources Information Center

    Bailey, James R.

    2014-01-01

    This essay engages the prospect and peril of employing rubrics in America. It discusses how institutional independence affects the enterprise, and addresses whether rubrics will be received as salvation or subservience by educational agents. It asks how rubrics can benefit stakeholders while examining their unintended consequences. It concludes by…

  15. Galaxias con núcleo doble. III

    NASA Astrophysics Data System (ADS)

    Gimeno, G.; Díaz, R. J.; Carranza, G.

    We performed new spectroscopic and photometric observations of late type galaxies with double nuclei and without previous studies. The subsample, constituted by double nuclei galaxies without tidal tails, was selected from the Double Nuclei Galaxies Preliminary Catalog (Gimeno, Díaz & Carranza 1999) and the observations were performed at Bosque Alegre Astrophysical Station. We report and discuss specially the results for ESO 416-G06, ESO 381-IG23 and Fairal 58. In all cases the secondary nucleus presents bluer color indexes than the main nucleus and also larger H? equivalent widths. These objects follow the trend of smaller radial velocity differences when smaller are the separations between both nuclei; this correlation was observed in previous works (e.g. Gimeno, Díaz & Carranza 1998). The general picture is consistent with the scenario of star formation enhanced by the capture of a minor or satellite galaxy.

  16. Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin--phenotypic and genotypic antibiotic resistance.

    PubMed

    Chaj?cka-Wierzchowska, Wioleta; Zadernowska, Anna; Nalepa, Beata; Sierpi?ska, Magda; ?aniewska-Trokenheim, ?ucja

    2015-04-01

    The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of antibiotic resistance. PMID:25475289

  17. Dietary inflammatory index and anthropometric measures of obesity in a population sample at high cardiovascular risk from the PREDIMED (PREvención con DIeta MEDiterránea) trial.

    PubMed

    Ruiz-Canela, M; Zazpe, I; Shivappa, N; Hébert, J R; Sánchez-Tainta, A; Corella, D; Salas-Salvadó, J; Fitó, M; Lamuela-Raventós, R M; Rekondo, J; Fernández-Crehuet, J; Fiol, M; Santos-Lozano, J M; Serra-Majem, L; Pinto, X; Martínez, J A; Ros, E; Estruch, R; Martínez-González, M A

    2015-03-28

    The dietary inflammatory index (DII) is a new tool to assess the inflammatory potential of the diet. In the present study, we aimed to determine the association between the DII and BMI, waist circumference and waist:height ratio (WHtR). We conducted a cross-sectional study of 7236 participants recruited into the PREvención con DIeta MEDiterránea trial. Information from a validated 137-item FFQ was used to calculate energy, food and nutrient intakes. A fourteen-item dietary screener was used to assess adherence to the Mediterranean diet (MeDiet). Sex-specific multivariable linear regression models were fitted to estimate differences (and 95 % CI) in BMI, waist circumference and WHtR across the quintiles of the DII. All nutrient intakes, healthy foods and adherence to the MeDiet were higher in the quintile with the lowest DII score (more anti-inflammatory values) except for intakes of animal protein, saturated fat and monounsaturated fat. Although an inverse association between the DII and total energy was apparent, the DII was associated with higher average BMI, waist circumference and WHtR after adjusting for known risk factors. The adjusted difference in the WHtR for women and men between the highest and lowest quintiles of the DII was 1·60 % (95 % CI 0·87, 2·33) and 1·04 % (95 % CI 0·35, 1·74), respectively. Pro-inflammatory scores remained associated with obesity after controlling for the effect that adherence to a MeDiet had on inflammation. In conclusion, the present study shows a direct association between the DII and indices of obesity, and supports the hypothesis that diet may have a role in the development of obesity through inflammatory modulation mechanisms. PMID:25720588

  18. Infrared spectra of matrix-isolated gaseous ternary oxides. Part V. The sodium—phosphorus—oxygen system

    NASA Astrophysics Data System (ADS)

    Teghil, R.; Bencivenni, L.; Cesaro, S. Nunziante; Szabó, Á.; Spoliti, M.; Maltese, M.

    1981-04-01

    The IR spectra of vapour from a Na 3PO 4, Na 5P 3O 10 and Na 2O-P 2O 5, mixture have been obtained in solid nitrogen at 12 K. The results suggest that it is possible to isolate both NaPO 3 and NaPO 2 when sodium tripolyphosphate and the Na 2O-P 2O 5 mixture are vaporized. There was no evidence of the NaPO molecule, reported to be one of the most abundant vapour species in mass-spectrometric work on the vaporization of Na 5P 3O 10.

  19. Effect of the glass melting condition on the processing of phosphate-based glass-ceramics with persistent luminescence properties

    NASA Astrophysics Data System (ADS)

    Massera, J.; Gaussiran, M.; Głuchowski, P.; Lastusaari, M.; Petit, L.; Hölsä, J.; Hupa, L.

    2016-02-01

    In this paper, we discuss the impact of the temperature and the duration of the melting on the persistent luminescence properties of phosphate glasses within the P2O5-Na2O-CaO and P2O5-Na2O-SrO systems prepared using a standard melting process in normal atmosphere by adding Sr4Al14O25:Eu2+,Dy3+ microparticles in the glass batch before melting. Glasses with persistent luminescence properties can be successfully prepared if the melting conditions are carefully controlled.

  20. EPR study of phosphate glasses containing two types of transitional metal ions

    NASA Astrophysics Data System (ADS)

    Cozar, O.; Ardelean, I.; Simon, V.; Mih, V.; Vedean, N.

    1999-05-01

    The following glass systems x(CuO·V 2O 5)(100 - x)[2P 2O 5 · PbO] and x·(MnO·V 2O 5)(100 - x)[2P 2O 5 · Na 2O] with 0 ? x ? 40 mol% were prepared and investigated by EPR spectroscopy. The obtained data suggest an octahedral-tetrahedral (Td) distorted local symmetry for Cu 2+ and Mn 2+ ions, and a square—pyramidal (C 4v) coordination for V 4+ ions. The mixed exchange pairs (Cu 2+-V 4+, Mn 4+) appear at high transition metal oxides content ( x > 10 mol%).

  1. Energy and Resource Saving of Steelmaking Process: Utilization of Innovative Multi-phase Flux During Dephosphorization Process

    NASA Astrophysics Data System (ADS)

    Matsuura, Hiroyuki; Hamano, Tasuku; Zhong, Ming; Gao, Xu; Yang, Xiao; Tsukihashi, Fumitaka

    2014-09-01

    An increase in the utilization efficiency of CaO, one of the major fluxing agents used in various steelmaking processes, is required to reduce the amount of discharged slag and energy consumption of the process. The authors have intensively focused on the development of innovative dephosphorization process by using so called "multi-phase flux" composed of solid and liquid phases. This article summarizes the research on the above topic done by the authors, in which the formation mechanisms of P2O5-containing phase during CaO or 2CaO·SiO2 dissolution into molten slag, the phase relationship between solid and liquid phases at equilibrium, and thermodynamic properties of P2O5-containing phase have been clarified. The reactions between solid CaO or 2CaO·SiO2 and molten CaO-FeO x -SiO2-P2O5 slag were observed by dipping solid specimen in the synthesized slag at 1573 K or 1673 K. The formation of the CaO-FeO layer and dual-phase layer of solid 2CaO·SiO2 and FeO x -rich liquid phase was observed around the interface from the solid CaO side toward the bulk slag phase side. Condensation of P2O5 into 2CaO·SiO2 phase as 2CaO·SiO2-3CaO·P2O5 solid solution was observed in both cases of CaO and 2CaO·SiO2 as solid specimens. Measurement of the phase relationship for the CaO-FeO x -SiO2-P2O5 system confirmed the condensation of P2O5 in solid phase at low oxygen partial pressure. The thermodynamics of 2CaO·SiO2-3CaO·P2O5 solid solution are to be clarified to quantitatively simulate the dephosphorization process, and the current results are also introduced. Based on the above results, the reduction of CaO consumption, the discharged slag curtailment, and energy-saving effects have been discussed.

  2. Study on the Strategies for the Soil and Water Resource Con-servation of Slopeland in Taiwan in Response to the Extreme Climate

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Cheng

    2014-05-01

    Global climate change results in extreme weather, especially ex-treme precipitation in Taiwan. Though the total amount of precipi-tation remains unchanged, the frequency of rainfall return period increases which affects slopeland and causes sediment disaster. In Taiwan, slopeland occupies about 73% of national territory. Under harsh environmental stress, soil and water conservation of slope-land becomes more important. In response to the trends of global-ization impacts of climate change, long term strategic planning be-comes more necessary. This study reviewed international practices and decision making process about soil and water conservation of slopeland; and conducted the compilation and analysis of water and soil conservation related research projects in Taiwan within the past five years. It is necessary for Taiwan to design timely adaptive strategies about conducting the all-inclusive conservation of na-tional territory, management and business operation of watershed based on the existing regulation with the effects of extreme weather induced by climate change and the changes of social-economic en-vironments. In order to realize the policy vision of "Under the premise of multiple uses, operating the sustainable business and management of the water and soil resources in the watershed through territorial planning in response to the climate and so-cial-economic environment change". This study concluded the future tasks for soil and water con-servation: 1.Design and timely amend strategies for soil and wand water conservation in response to extreme weather. 2. Strengthen the planning and operating of the land management and integrated conservation of the water and soil resources of key watershed. 3. Manage and operate the prevention of debris flow disaster and large-scale landslide. 4. Formulate polices, related regulations and assessment indicators of soil and water conservation. 5. Maintain the biodiversity of the slopeland and reduce the ecological footprint. 6. Conduct soil and water conservation research according to the importance and urgency of policies. 7. Implement the international cooperation, technology communication, talent cultivation, and integrated education and promotion.

  3. Reversible CO binding enables tunable CO/H? and CO/N? separations in metal-organic frameworks with exposed divalent metal cations.

    PubMed

    Bloch, Eric D; Hudson, Matthew R; Mason, Jarad A; Chavan, Sachin; Crocellà, Valentina; Howe, Joshua D; Lee, Kyuho; Dzubak, Allison L; Queen, Wendy L; Zadrozny, Joseph M; Geier, Stephen J; Lin, Li-Chiang; Gagliardi, Laura; Smit, Berend; Neaton, Jeffrey B; Bordiga, Silvia; Brown, Craig M; Long, Jeffrey R

    2014-07-30

    Six metal-organic frameworks of the M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) structure type are demonstrated to bind carbon monoxide reversibly and at high capacity. Infrared spectra indicate that, upon coordination of CO to the divalent metal cations lining the pores within these frameworks, the C-O stretching frequency is blue-shifted, consistent with nonclassical metal-CO interactions. Structure determinations reveal M-CO distances ranging from 2.09(2) Å for M = Ni to 2.49(1) Å for M = Zn and M-C-O angles ranging from 161.2(7)° for M = Mg to 176.9(6)° for M = Fe. Electronic structure calculations employing density functional theory (DFT) resulted in good agreement with the trends apparent in the infrared spectra and crystal structures. These results represent the first crystallographically characterized magnesium and zinc carbonyl compounds and the first high-spin manganese(II), iron(II), cobalt(II), and nickel(II) carbonyl species. Adsorption isotherms indicate reversible adsorption, with capacities for the Fe, Co, and Ni frameworks approaching one CO per metal cation site at 1 bar, corresponding to loadings as high as 6.0 mmol/g and 157 cm(3)/cm(3). The six frameworks display (negative) isosteric heats of CO adsorption ranging from 52.7 to 27.2 kJ/mol along the series Ni > Co > Fe > Mg > Mn > Zn, following the Irving-Williams stability order. The reversible CO binding suggests that these frameworks may be of utility for the separation of CO from various industrial gas mixtures, including CO/H2 and CO/N2. Selectivities determined from gas adsorption isotherm data using ideal adsorbed solution theory (IAST) over a range of gas compositions at 1 bar and 298 K indicate that all six M2(dobdc) frameworks could potentially be used as solid adsorbents to replace current cryogenic distillation technologies, with the choice of M dictating adsorbent regeneration energy and the level of purity of the resulting gases. PMID:24999916

  4. HP and UHT metamorphic associations in the Day Nui Con Voi?northwestern Vietnam: The consequence of convergence between the Indian and the Eurasian plates

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Liu, J.; Tran, M. D.; Nguyen, Q. L.

    2014-12-01

    The Red River shear zone (RRSZ) is the most significant geologic discontinuity in Southeast Asia. The Day Nui Con Voi (DNCV) massif at the southernmost part of the shear zone bears records of Cenozoic RRSZ activity. The DNCV in northwestern Vietnam predominantly consists of HP granulite facies metapelites, and lenticular enclaves of HP mafic granulites, calc-silicate granulites and UHT aluminum-rich rocks in the metapelites. HP granulites are characterized by the key associations of garnet-kyanite-ternary feldspar (in metapelites) and garnet-clinopyroxene-plagioclase-quartz (in mafic granulites). In the latter case, rocks are typically orthopyroxene-free. The peak assemblage of the HP metapelites includes garnet + kyanite + ternary feldspar + quartz + rutile. The peak assemblage of the HP mafic granulites is garnet + clinopyroxene + plagioclase + quartz. Meanwhile, the peak assemblage of the calc-silicate granulites is high-Ca garnet (Grs>50) + diopside + scapolite + quartz. On the other hand, characteristic UHT metamorphic assemblage occur as the coexistence of spinel and quartz which indicates the metamorphic temperature is higher than 900?. The peak assemblage of the UHT rocks in DNCV is corundum + spinel + garnet + sillimanite + quartz. P-T conditions of peak metamorphism within HP granulite facies are: T = 750?850?, P = 12.5?14kbar. The temperature of UHT metamorphism is higher than 900?, the pressure is higher than 9?9.4 kbar. SHRIMP U-Pb dating of zircons from the HP mafic granulites and UHT rocks gave minimum ages of ca. 59 Ma and 40 Ma, respectively. HP metapelites gave ca. 60~50Ma and 30Ma. The above facts suggest the DNCV massif experienced HP granulite facies at its peak metamorphism at ˜59 Ma. Thermal disturbance on the local scale to UHT metamorphism occurred at ˜40 Ma. Then isothermal decompression to medium-pressure granulite facies occurred at ˜30Ma, which may reflect a rapid exhumation. The HP rocks are interpreted to be resulted from crustal thickening due to far-field compression during Indian-Eurasian convergence. However the high heat flow for UHT metamorphism was possibly attributed to upwelling of asthenosphere triggered by delamination of the thickened crust. The delamination may also be responsible for subsequent generation of high potassic magmas along the RRSZ belt.

  5. Comparison between dynamic cystocolpoproctography and dynamic pelvic floor MRI: pros and cons: which is the "functional" examination for anorectal and pelvic floor dysfunction?

    PubMed

    Maglinte, Dean D T; Hale, Douglass S; Sandrasegaran, Kumar

    2013-10-01

    "Functional" imaging of anorectal and pelvic floor dysfunction has assumed an important role in the diagnosis and management of these disorders. Although defecography has been widely practiced for decades to evaluate the dynamics of rectal emptying, debate concerning its clinical relevance, how it should be done and interpreted continues. Due to the recognition of the association of defecatory disorders with pelvic organ prolapse in women, the need to evaluate the pelvic floor as a unit has arisen. To meet this need, defecography has been extended to include not only evaluation of defecation disorders but also the rest of the pelvic floor by opacifying the small bowel, vagina, and the urinary bladder. The term "dynamic cystocolpoproctography" (DCP) has been appropriately applied to this examination. Rectal emptying performed with DCP provides the maximum stress to the pelvic floor resulting in complete levator ani relaxation. In addition to diagnosing defecatory disorders, this method of examination demonstrates maximum pelvic organ descent and provides organ-specific quantification of organ prolapse, information that is only inferred by means of physical examination. It has been found to be of clinical value in patients with defecation disorders and the diagnosis of associated prolapse in other compartments that are frequently unrecognized by history taking and the limitations of physical examination. Pelvic floor anatomy is complex and DCP does not show the anatomical details pelvic magnetic resonance imaging (MRI) provides. Technical advances allowing acquisition of dynamic rapid MRI sequences has been applied to pelvic floor imaging. Early reports have shown that pelvic MRI may be a useful tool in pre-operative planning of these disorders and may lead to a change in surgical therapy. Predictions of hypothetical increase cancer incidence and deaths in patients exposed to radiation, the emergence of pelvic floor MRI in addition to questions relating to the clinical significance of DCP findings have added to these controversies. This review analyses the pros and cons between DCP and dynamic pelvic floor MRI, addresses imaging and interpretive controversies, and their relevance to clinical management. PMID:22446896

  6. Do not disturb the animals! or, how Con Edison saved $300,000 using a trenchless technology to renew 3,000 feet of leaking gas main at the Bronx Zoo

    SciTech Connect

    Bufe, M.

    1995-07-01

    Every leaking gas main presents a challenge. But when that leaking main follows a series of sweeping bends on its route through North America`s largest urban wildlife park, it presents a special challenge. That was the situation Consolidated Edison Company of New York Inc. recently faced when numerous leaks were discovered along 3,000 feet of a 95-year-old, 12-inch cast-iron main that winds through New York City`s Bronx Zoo. Con Edison knew it needed a long-term solution to this increasingly common problem. Thanks to the cooperative efforts of the utility`s operations and research departments and the Gas Research Institute (GRI), Con Edison also knew about a trenchless technology that could renew the pipe with minimal impact to the environment--while saving the utility a substantial sum of money in the process. In the Paltem system, a woven polyester hose is injected with an epoxy resin and then inverted (turned inside out) into a pipe at an access pit. The liner then bonds to the inside wall of the pipe, forming a smooth, flexible and pressure-resistant lining. The process is environmentally safe, requires very little excavation and can be installed in days, rather than the weeks or months it can take to dig up and replace existing pipe.

  7. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires.

    PubMed

    Balán, Iván C; Carballo-Diéguez, Alex; Marone, Rubén O; Pando, María A; Barreda, Victoria; Avila, María M

    2011-03-01

    El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  8. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires

    PubMed Central

    Balán, Iván C.; Carballo-Diéguez, Alex; Marone, Rubén O.; Pando, María A.; Barreda, Victoria; Ávila, María M.

    2011-01-01

    Resumen El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  9. 40 CFR 60.211 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... weight for eventual consumption as a fertilizer. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods specified in § 60.214, or equivalent or alternative methods. (c) Equivalent P 2 O 5 feed means the quantity of phosphorus, expressed as phosphorus...

  10. 40 CFR 60.211 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... weight for eventual consumption as a fertilizer. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods specified in § 60.214, or equivalent or alternative methods. (c) Equivalent P 2 O 5 feed means the quantity of phosphorus, expressed as phosphorus...

  11. 40 CFR 60.211 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... weight for eventual consumption as a fertilizer. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods specified in § 60.214, or equivalent or alternative methods. (c) Equivalent P 2 O 5 feed means the quantity of phosphorus, expressed as phosphorus...

  12. Response of Louisiana ratoon sugarcane to phosphorus fertilizer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of phosphorus fertilizer on sugarcane (interspecific hybrids of Saccharum Spp. cv. 'LCP 85-384') yield components and soil properties were evaluated at seven locations in Louisiana. Five rates of phosphorus fertilizer (0 - 84 kg P2O5 ha-1) were applied to first-, second- and third-ratoo...

  13. 21 CFR 74.2053 - D&C Black No. 3.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2053 D&C Black No. 3. (a) Identity. The color additive D&C... may be avoided by current good manufacturing practices: (1) Calcium hydroxyapatite (CaO and P2O5), not... cosmetics in amounts consistent with current good manufacturing practice: Eyeliner, eye shadow, mascara,...

  14. 21 CFR 74.2053 - D&C Black No. 3.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2053 D&C Black No. 3. (a) Identity. The color additive D&C... may be avoided by current good manufacturing practices: (1) Calcium hydroxyapatite (CaO and P2O5), not... cosmetics in amounts consistent with current good manufacturing practice: Eyeliner, eye shadow, mascara,...

  15. Melon types and cultivars grown with organic and synthetic fertilizers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For three years, twelve melon cultivars were grown with either synthetic or organic (poultry litter) fertilizer. Both fertilizers were applied at 100 lbs N, 100 lbs P2O5, and 100 lbs K2O per acre. In order to satisfy the requirements of the USDA National Organic Program, all fertilizer was applied...

  16. 40 CFR 60.210 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid Plants § 60.210 Applicability and... each superphosphoric acid plant having a design capacity of more than 15 tons of equivalent P2O5 feed...: evaporators, hot wells, acid sumps, and cooling tanks. (b) Any facility under paragraph (a) of this...

  17. 40 CFR 60.210 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid Plants § 60.210 Applicability and... each superphosphoric acid plant having a design capacity of more than 15 tons of equivalent P2O5 feed...: evaporators, hot wells, acid sumps, and cooling tanks. (b) Any facility under paragraph (a) of this...

  18. 40 CFR 60.211 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Superphosphoric Acid Plants § 60.211 Definitions. As used in this subpart, all terms not defined herein shall have the meaning given them in the Act and in subpart A of this part. (a) Superphosphoric acid plant means any facility which concentrates wet-process phosphoric acid to 66 percent or greater P2O5 content...

  19. 40 CFR 60.210 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid Plants § 60.210 Applicability and... each superphosphoric acid plant having a design capacity of more than 15 tons of equivalent P2O5 feed...: evaporators, hot wells, acid sumps, and cooling tanks. (b) Any facility under paragraph (a) of this...

  20. 40 CFR 60.210 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid Plants § 60.210 Applicability and... each superphosphoric acid plant having a design capacity of more than 15 tons of equivalent P2O5 feed...: evaporators, hot wells, acid sumps, and cooling tanks. (b) Any facility under paragraph (a) of this...

  1. 40 CFR 60.210 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Performance for the Phosphate Fertilizer Industry: Superphosphoric Acid Plants § 60.210 Applicability and... each superphosphoric acid plant having a design capacity of more than 15 tons of equivalent P2O5 feed...: evaporators, hot wells, acid sumps, and cooling tanks. (b) Any facility under paragraph (a) of this...

  2. 40 CFR 63.621 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., as measured by reference methods specified in 40 CFR part 60, appendix A, Method 13 A or B, or by... phosphorus, expressed as phosphorous pentoxide, fed to the process. Equivalent P 2O5 stored means the quantity of phosphorus, expressed as phosphorus pentoxide, being cured or stored in the affected...

  3. 40 CFR 63.621 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., as measured by reference methods specified in 40 CFR part 60, appendix A, Method 13 A or B, or by... phosphorus, expressed as phosphorous pentoxide, fed to the process. Equivalent P 2O5 stored means the quantity of phosphorus, expressed as phosphorus pentoxide, being cured or stored in the affected...

  4. 40 CFR 63.621 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., as measured by reference methods specified in 40 CFR part 60, appendix A, Method 13 A or B, or by... phosphorus, expressed as phosphorous pentoxide, fed to the process. Equivalent P 2O5 stored means the quantity of phosphorus, expressed as phosphorus pentoxide, being cured or stored in the affected...

  5. Mass Transfer Behavior of Phosphorus from the Liquid Slag Phase to Solid 2CaO·SiO2 in the Multiphase Dephosphorization Slag

    NASA Astrophysics Data System (ADS)

    Xie, Senlin; Wang, Wanlin; Luo, Zhican; Huang, Daoyuan

    2016-03-01

    The mass transfer behavior of phosphorus in the multiphase dephosphorization slag at 1623 K (1350 °C) is investigated in this article by adding the reagent P2O5 powders into the CaO-FeOt-SiO2 slag saturated with a directly precipitated 2CaO·SiO2 phase. The results show that the phosphorus was first quickly dissolved and transferred from the liquid slag to the precipitated solid 2CaO·SiO2 particle; then it reacted with the solid 2CaO·SiO2 particle to form (2CaO·SiO2-3CaO·P2O5) solid solution at the edge of a large solid particle. The further diffusion of phosphorus from the formed (2CaO·SiO2-3CaO·P2O5) solid solution reaction layer into the core of the 2CaO·SiO2 particle is the limiting step during the enrichment-phosphorus process. It is observed that the enrichment-phosphorus process is changed when the amount of added P2O5 content is increased and the formed solid solution phase is torn and peeled off from the surface of the 2CaO·SiO2 particle. In addition, the study shows that the solid solution structure is changed and becomes more compacted with the addition of P2O5 content, leading to the increment of solid solution density.

  6. El rol de Ia colaboracion y el Modelo de Aprendizaje Basado en Proyectos (ABPr) mediante el lente de la Teoria de Actividad (CHAT): un estudio de caso con estudiantes de 9no grado

    NASA Astrophysics Data System (ADS)

    Delgado, Isabel C.

    Los modelos de eensenanza y aprendizaje constructivistas conceptualizan el aprendizaje como un proceso activo. El modelo de Aprendizaje Basado en Proyectos (ABPr) se distingue por una serie de componentes, entre los cuales se destaca el aspecto colaborativo y cooperativo como un reto al momento de su implantacion. Son pocas las investigaciones que se concentran en este aspecto del modelo. En este estudio, se analizaron las diversas interacciones que surgen durante la implantacion de una unidad curricular sobre el tema de Geologia de Puerto Rico, la cual se diseno con el modelo ABPr cuyo enfoque es orientacion a proyectos. Particularmente, se examinaron las interacciones sociales que surgen entre los pares y entre pares y docente durante el proceso de planificacion y desarrollo de los productos finales, al igual que las interacciones entre los estudiantes y el material didactico en estas etapas del modelo. La investigacion es de tipo cualitativo e incorpora como diseno el estudio de caso. Las diversas interacciones constituyen la unidad de analisis. En el estudio participaron 19 estudiantes de 9no grado, a quienes se organizaron en 5 grupos colaborativos por temas de interes (Pangea, Placas tectonicas, Volcanes, Tsunamis y Terremotos). Las tecnicas que se utilizaron para recopilar los datos fueron: observaciones participativas, grupos focales y analisis de documentos (cuadernos reflexivos y respuestas de los estudiantes a la pregunta central del proyecto). Para el analisis de los datos se aplico la teoria de actividad (CHAT) que concentra la unidad de analisis en la actividad humana en un contexto particular. Los resultados del estudio senalan que las interacciones entre pares, entre pares y docente, asi como entre estudiantes y material didactico son fundamentales en el proceso de aprendizaje. Una mayor interaccion entre pares durante las etapas de planificar y desarrollar los productos finales de la unidad, promueve una mejor comprension de los conceptos de la unidad, segun evidencia los productos finales del ABPr. La interaccion con el docente es muy importante para mediar los conflictos y desacuerdos que surgen como parte de las interacciones entre pares. Por lo tanto, el uso de diversas estrategias de andamiaje por parte del docente durante las reuniones de los grupos colaborativos es esencial para el exito del modelo ABPr.

  7. Revision curricular a partir de un analisis comparativo de las discrepancias en los curriculos de una escuela de optometria en Puerto Rico con las competencias requeridas para las agencias de revalida y acreditacion 2004

    NASA Astrophysics Data System (ADS)

    Rivera Pacheco, Andres

    El proposito de esta investigacion, un estudio cualitativo de caso, fue comparar y contrastar el curriculo vigente de la Escuela de Optometria de la UIAPR con las competencias y estandares requeridos por las agencias de acreditacion y de revalida. Con este proposito, decidimos realizar una revision y un analisis de documentos: el prontuario de cada uno de los cursos de los curriculos implantados en el 1993 y en el 2001; las competencias y estandares establecidos por las agencias de revalida y de acreditacion; y las estadisticas en las que se analiza el porcentaje de estudiantes que aprueban cada una de las partes de los examenes de revalida entre el 1998 al 2003. Se realizaron entrevistas dirigidas para dar apoyo y complementar la revision y el analisis de estos documentos. Los participantes de las entrevistas fueron tres estudiantes de la clase de optometria del 2004 (ultima clase del curriculo del 1993); tres estudiantes de la clase de optometria del 2005 (primera clase graduanda del curriculo vigente) y tres profesores y/o directores de los Departamentos de Ciencias Basicas, Ciencias Clinicas y Cuidado al Paciente. Esta investigacion se enmarco en el modelo de evaluacion curricular de discrepancia de Malcolm Provus y en el modelo de desarrollo basado en competencias. Uno de los hallazgos mas importantes del estudio es que los cambios que se implantaron al curriculo del 2001 no han logrado que los estudiantes mejoren su ejecucion en los examenes de revalida. Por otro lado, se encontro que el curriculo vigente atiende completamente los estandares de la practica de Optometria, pero no las competencias. Esta informacion fue validada mediante el uso de una tabla de cotejo para el analisis de los cursos y de la informacion obtenida de las entrevistas. El estudio determina y concluye que existen discrepancias entre los prontuarios de los cursos del curriculo y las competencias requeridas por la agencia de revalida. Segundo, que el Departamento de Ciencias Basicas es el que presenta mas deficiencias en el desarrollo de las competencias. El investigador recomienda disenar e implantar un curriculo basado en competencias y proveer formacion en didactica y procesos de aprendizaje a los profesores.

  8. Brewers' spent grain (BSG) protein hydrolysates decrease hydrogen peroxide (H2O2)-induced oxidative stress and concanavalin-A (con-A) stimulated IFN-? production in cell culture.

    PubMed

    McCarthy, Aoife L; O'Callaghan, Yvonne C; Connolly, Alan; Piggott, Charles O; FitzGerald, Richard J; O'Brien, Nora M

    2013-11-01

    The present study investigated the bioactivity of protein hydrolysates and fractionated hydrolysates prepared from brewers' spent grain (BSG) using proteases, including Alcalase 2.4L, Flavourzyme and Corolase PP. Hydrolysates were designated K-Y, including fractionated hydrolysates with molecular weight (m.w.) < 3, <5 and >5 kDa. Where computable, IC50 values were lower in U937 (1.38-9.78%) than Jurkat T cells (1.15-13.82%). Hydrolysates L, Q and R and fractionated hydrolysates of U and W (<3, <5, >5 kDa) significantly (P < 0.01) protected against hydrogen peroxide (H2O2)-induced reduction of superoxide dismutase (SOD) activity. A fractionated hydrolysate of W (<5 kDa) protected against H2O2-induced DNA damage, P < 0.01. Hydrolysates K, N, P, U, U > 5 kDa, V, V > 5 kDa, W, W > 5 kDa significantly (P < 0.05) reduced a concanavlin-A (con-A) stimulated production of interferon-? (IFN-?). In conclusion, BSG protein hydrolysates demonstrate bioactivity in vitro; lower m.w. hydrolysates (<3, <5 kDa) show greatest antioxidant activity and unfractionated or higher m.w. hydrolysates (>5 kDa) possess anti-inflammatory effects. PMID:24113874

  9. Multi-analytical approach applied to the provenance study of marbles used as covering slabs in the archaeological submerged site of Baia (Naples, Italy): The case of the "Villa con ingresso a protiro"

    NASA Astrophysics Data System (ADS)

    Ricca, Michela; Belfiore, Cristina Maria; Ruffolo, Silvestro Antonio; Barca, Donatella; De Buergo, Monica Alvarez; Crisci, Gino Mirocle; La Russa, Mauro Francesco

    2015-12-01

    This paper is focused on archaeometric investigations of white marbles taken from the submerged archaeological site of Baia (Naples). The marine area includes the ruins of this ancient Roman city, whose structures range from luxurious maritime villas and imperial buildings with private thermae and tabernae, to more simple and modest houses. Analyses were carried out on fifty marble fragments of covering slabs, belonging to several pavements of the monumental villa, called the Villa con ingresso a protiro, in order to ascertain their provenance. The most distinctive properties of marbles are their variety of textural property especially regarding grain size (MGS), associated with the Mn content and the variation of stable isotopes. These features, supported by the contribution of other variables and studies, establish the basis for the correct identification of the marbles. For this purpose, minero-petrographic and geochemical techniques were used. Results were compared with literature data of white marbles commonly used in antiquity, especially in the Mediterranean basin and showed that a variety of precious marbles from Carrara, Docimium (Afyon), Thasos-D, Aphrodisias, Proconnesos (Marmara), Paros and Pentelicon were used in the ancient roman city of Baia, confirming the importance of the submerged archaeological site and also allowing researchers to broaden the existing database.

  10. Has allogeneic stem cell cryopreservation been given the 'cold shoulder'? An analysis of the pros and cons of using frozen versus fresh stem cell products in allogeneic stem cell transplantation.

    PubMed

    Frey, N V; Lazarus, H M; Goldstein, S C

    2006-09-01

    Donor stem cells for allogeneic transplant traditionally are collected and transfused 'fresh' into the recipient on the day of transplant; alternatively such cells can be collected in advance and cryopreserved until needed. Most centers favor the former approach based on theoretical concerns that cryopreservation and thawing may worsen clinical outcomes. Limited published data from single institution retrospective studies show no significant impairment of engraftment or reduced day 100 survival for cryopreserved bone marrow recipients. There are no reported outcomes for recipients of cryopreserved peripheral blood allografts. Use of cryopreserved stem cells is associated with a higher incidence of adverse events (transfusion reactions, bacterial graft contamination and collection of grafts which are not utilized). Conversely, use of cryopreserved grafts introduces a greater flexibility into a stressed healthcare system and results in a more streamlined experience for the donor. Some data suggest that transplantation with a cryopreserved product may lower the incidence of acute graft-versus-host disease. We compare the pros and cons of using 'fresh' versus cryopreserved stem cell products for allogeneic transplantation and suggest that the current standard of using 'fresh' products may not be warranted. We also suggest future areas of exploration to better elucidate this issue. PMID:16892075

  11. Implantation des sites de soins communautaires en République Démocratique du Congo: consécration d'un double standard dans l'accès aux soins

    PubMed Central

    Dunia, Gisèle Mawazo Binti

    2013-01-01

    Depuis 2005, la République Démocratique du Congo a amorcé l'implantation des sites de soins communautaires. Cette stratégie a pour objectif de rapprocher les services de santé des populations éloignées. Bien que cela parte d'une bonne intention, elle résulte, à notre sens, en une consécration d'un système de santé à deux vitesses. En effet, les populations vivant en ville ont accès à des soins prestés par des agents de santé formés alors que celles vivant en milieu rural reculé ont pour prestataires de soins des relais communautaires. Cette situation marginalise encore plus des populations dont la situation géographique est déjà préoccupante. Pourtant, la population est prête à parcourir des kilomètres en échange d'un service qu'elle estime de qualité. PMID:23785563

  12. Determining the Origin of Phosphates in Lherzolitic Shergottites Through Phosphate Saturation Experiments

    NASA Astrophysics Data System (ADS)

    Calvin, C.; Rutherford, M.

    2007-12-01

    Phosphorous has been correlated with sulfur and chlorine in martian soils with some soils containing several wt % P2O5 and high-P2O5 layer covers many rocks. However, using the RAT to remove the top few mm of some rocks revealed zones of low-P2O5 in the outer mm relative to the interior composition. This suggests that some igneous rocks of Mars are high in P2O5 and that over time phosphorous has been mobilized into the martian soils. In martian meteorites, phosphorous has been detected in high concentrations relative to terrestrial basalts and cumulates. High intensity x-ray maps of lherzolitic shergottite ALH 77005 reveal phosphates in olivine-hosted melt inclusions and P2O5 zoning in the host-olivine. Analyses of rehomogenized olivine-hosted melt inclusions reveal high-P2O5 glasses (>5 wt %). As phosphates are the major reservoir of REE in martian meteorites, determining if the phosphates are primary igneous or secondary sedimentary minerals may have significant consequences for use of REE as oxybarometers and radiogenic-isotopic dating systems in these meteorites. Therefore, an experimental investigation was initiated to determine whether the phosphates are primary igneous minerals or secondary weathering products. The phosphate saturation curve in SNC magmatic compositions has been studied experimentally by synthesizing the parental melt composition of lherzolitic shergottite ALH 77005 and performing anhydrous crystallization experiments in TZM pressure vessels. The parental melt composition was then doped with 5 wt % P2O5 in the form of CaHPO4 and the crystallization experiments were repeated. ALH 77005's parental melt saturated phosphate near 7 wt % at 1165°C and 5 wt % at 1150°C. These saturation values illustrate how high-P2O5 would have to build up before phosphates would nucleate and are consistent with high-2O5 content found in rehomogenized olivine-hosted melt inclusions. These saturation values are higher than the reported saturation for lunar and typical terrestrial basalts, which may reflect differences in the composition, volatile content, and/or the oxidation state of shergottite magmas. The presence of phosphate-saturated melts in rehomogenized, olivine-hosted melt inclusions suggests that olivine contains previously unaccounted for high levels of phosphate. If the phosphates are magmatic in origin, the evidence suggests that phosphates saturated earlier in the crystallization of lherzolitic shergottite ALH 77005 than previous authors have indicated and therefore phosphates contained in olivines have a larger impact on REE evolution of the magma than if olivine had been crystallizing alone. If the included phosphates are secondary in origin, the presence of enough P2O5 to saturate a melt inclusion with phosphate during rehomogenization suggests that mineral separates of olivine would still carry enough REE to have a significant effect on studies that attempt to use REE for oxybarometers and radiogenic-isotopic dating.

  13. The pros and cons of phytoestrogens

    PubMed Central

    Patisaul, Heather B.; Jefferson, Wendy

    2011-01-01

    Phytoestrogens are plant derived compounds found in a wide variety of foods, most notably soy. A litany of health benefits including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms, are frequently attributed to phytoestrogens but many are also considered endocrine disruptors, indicating that they have the potential to cause adverse health effects as well. Consequently, the question of whether or not phytoestrogens are beneficial or harmful to human health remains unresolved. The answer is likely complex and may depend on age, health status, and even the presence or absence of specific gut microflora. Clarity on this issue is needed because global consumption is rapidly increasing. Phytoestrogens are present in numerous dietary supplements and widely marketed as a natural alternative to estrogen replacement therapy. Soy infant formula now constitutes up to a third of the US market, and soy protein is now added to many processed foods. As weak estrogen agonists/antagonists with molecular and cellular properties similar to synthetic endocrine disruptors such as Bisphenol A (BPA), the phytoestrogens provide a useful model to comprehensively investigate the biological impact of endocrine disruptors in general. This review weighs the evidence for and against the purported health benefits and adverse effects of phytoestrogens. PMID:20347861

  14. [Generic drugs in psychopharmacology: pros and cons].

    PubMed

    Cuenca, E; Zaragozá, F

    1999-01-01

    Legislation to facilitate process for generic products has been enacted and generic drugs have entered the market soon after the patent for the brand-name agent have expired. In every instance, the rationale has been economic since it is generally assumed that the copies are not only therapeutically equivalent but also a great deal less expensive than the original. Sometimes this may be so. In this short review several comments are made in order to establish the variables that may influence bioequivalence between the brand-name drug and its generics. Among them emphasis is given to the particle sizes, pharmaceutical supply, choice of the right excipient, in order to avoid possible interactions with the drug, ingredient quality and purity, etc. All these variables must be carefully controlled. Even so a patient who is changed from a trade name product to a generic drug (or vice versa) may respond a little differently, which is important in Psychopharmacology. Two or more products should be considered biologically equivalent only when it can demonstrated that they fulfil three conditions: that they have the same pharmaceutical properties; that they are equally effective in therapeutic use and that they are tolerated equally by patients being treated for the indicated uses. Regulatory agencies could require subsequent versions of an original therapeutic product the type of data regarding pharmacology, toxicology and chemical assessment that was mandatory for the introduction of the original. PMID:10611558

  15. Jets estelares observados con GSAOI/GEMINI

    NASA Astrophysics Data System (ADS)

    Ferrero, L. V.; Gómez, M.; Gunthard, G.

    2015-08-01

    In this contribution we present H (2.122 m) and K (2.2 m) images of the Herbig-Haro object HH 137 and the stellar jet MHO 1502, taken with GSAOI+GeMS/GEMINI. The high resolution of GSAOI allows us to identify, with great definition, new internal structures not previously reported in the literature. We perform a detailed morphological description of each object. We detect the near-infrared counterpart of HH 137, that shows a bow shock-like terminal structure and an irregular profile. MHO 1502 shows a gentle ``S-shape'' as well as several nearby nebular (H) regions, probably not associated with this object, with bow shock-like shapes, not previously cataloged.

  16. Update on vitamin D: pros and cons

    PubMed Central

    Cipriani, Cristiana; Piemonte, Sara; Cilli, Mirella; Pepe, Jessica; Minisola, Salvatore

    2015-01-01

    Summary Controversies on vitamin D currently represent a challenging topic in mineral metabolism research. In particular, current guidelines on vitamin D supplementation did not report consistent recommendation and the issue related to beneficial vs harmful effects of loading vitamin D doses did not lead to any firm universal conclusion. Finally, serum and clinical outcomes of vitamin D supplementation, particularly as far as extra-skeletal effect of the hormone, need to be further investigated. PMID:26811700

  17. The pros and cons of phytoestrogens.

    PubMed

    Patisaul, Heather B; Jefferson, Wendy

    2010-10-01

    Phytoestrogens are plant derived compounds found in a wide variety of foods, most notably soy. A litany of health benefits including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms, are frequently attributed to phytoestrogens but many are also considered endocrine disruptors, indicating that they have the potential to cause adverse health effects as well. Consequently, the question of whether or not phytoestrogens are beneficial or harmful to human health remains unresolved. The answer is likely complex and may depend on age, health status, and even the presence or absence of specific gut microflora. Clarity on this issue is needed because global consumption is rapidly increasing. Phytoestrogens are present in numerous dietary supplements and widely marketed as a natural alternative to estrogen replacement therapy. Soy infant formula now constitutes up to a third of the US market, and soy protein is now added to many processed foods. As weak estrogen agonists/antagonists with molecular and cellular properties similar to synthetic endocrine disruptors such as Bisphenol A (BPA), the phytoestrogens provide a useful model to comprehensively investigate the biological impact of endocrine disruptors in general. This review weighs the evidence for and against the purported health benefits and adverse effects of phytoestrogens. PMID:20347861

  18. Nanoparticles: health effects--pros and cons.

    PubMed

    Gwinn, Maureen R; Vallyathan, Val

    2006-12-01

    With the advent of nanotechnology, the prospects for using engineered nanomaterials with diameters of < 100 nm in industrial applications, medical imaging, disease diagnoses, drug delivery, cancer treatment, gene therapy, and other areas have progressed rapidly. The potential for nanoparticles (NPs) in these areas is infinite, with novel new applications constantly being explored. The possible toxic health effects of these NPs associated with human exposure are unknown. Many fine particles generally considered "nuisance dusts" are likely to acquire unique surface properties when engineered to nanosize and may exhibit toxic biological effects. Consequently, the nuisance dust may be transported to distant sites and could induce adverse health effects. In addition the beneficial uses of NPs in drug delivery, cancer treatment, and gene therapy may cause unintentional human exposure. Because of our lack of knowledge about the health effects associated with NP exposure, we have an ethical duty to take precautionary measures regarding their use. In this review we highlight the possible toxic human health effects that can result from exposure to ultrafine particles (UFPs) generated by anthropogenic activities and their cardiopulmonary outcomes. The comparability of engineered NPs to UFPs suggests that the human health effects are likely to be similar. Therefore, it is prudent to elucidate their toxicologic effect to minimize occupational and environmental exposure. Highlighting the human health outcomes caused by UFPs is not intended to give a lesser importance to either the unprecedented technologic and industrial rewards of the nanotechnology or their beneficial human uses. PMID:17185269

  19. Licensing: pros and cons for biotech.

    PubMed

    Villiger, Ralph; Bogdan, Boris

    2009-03-01

    This article guides the reader through strategic considerations when facing the option to license a drug development project. It is crucial to understand these licensing events in their full complexity in order to achieve maximum value for the company and the shareholders, while minimizing risk. First, the nature of various license agreements and the needs of licensor and licensee are discussed. Second, the main strategic issues for the licensor are explained and a guideline, how to come to a decision whether to license and to what terms, is given. Third, the authors explain how to overcome different assumptions when negotiating a license contract. PMID:19200456

  20. Interacciones de galaxias: sistemas con puentes tidales

    NASA Astrophysics Data System (ADS)

    Mesa, V.; Alonso, S.; Duplancic, F.; Lambas, D. G.

    2015-08-01

    In this work we present a sample of interacting galaxy pairs connected by a bridge, obtained from a visual classification of a pair catalogue derived from the seventh data release of the Sloan Digital Sky Survey (SDSS-DR7). We present preliminary results of the general characteristics of galaxies in these systems, such as specific star formation rate, age of the stellar populations, concentration index, colour and local density environment.

  1. I-ConFIRM Steering Committee

    Cancer.gov

    Skip to Main Content at the National Institutes of Health | www.cancer.gov Epidemiology and Genomics Research In NCI's Division of Cancer Control and Population Sciences Search EGRP: Main Menu EGRP Home About the Program Mission & Vision Organizational

  2. Pros and cons of hydraulic drilling

    SciTech Connect

    Not Available

    1984-06-01

    The advantages and disadvantages of using hydraulic drilling are discussed. The low maintenance, energy efficiency, drilling speeds, and operating costs are the main advantages of the hydraulic drills. The economics and maintenance of air drills are also compared.

  3. Nanoparticles: Health Effects—Pros and Cons

    PubMed Central

    Gwinn, Maureen R.; Vallyathan, Val

    2006-01-01

    With the advent of nanotechnology, the prospects for using engineered nanomaterials with diameters of < 100 nm in industrial applications, medical imaging, disease diagnoses, drug delivery, cancer treatment, gene therapy, and other areas have progressed rapidly. The potential for nanoparticles (NPs) in these areas is infinite, with novel new applications constantly being explored. The possible toxic health effects of these NPs associated with human exposure are unknown. Many fine particles generally considered “nuisance dusts” are likely to acquire unique surface properties when engineered to nanosize and may exhibit toxic biological effects. Consequently, the nuisance dust may be transported to distant sites and could induce adverse health effects. In addition the beneficial uses of NPs in drug delivery, cancer treatment, and gene therapy may cause unintentional human exposure. Because of our lack of knowledge about the health effects associated with NP exposure, we have an ethical duty to take precautionary measures regarding their use. In this review we highlight the possible toxic human health effects that can result from exposure to ultrafine particles (UFPs) generated by anthropogenic activities and their cardiopulmonary outcomes. The comparability of engineered NPs to UFPs suggests that the human health effects are likely to be similar. Therefore, it is prudent to elucidate their toxicologic effect to minimize occupational and environmental exposure. Highlighting the human health outcomes caused by UFPs is not intended to give a lesser importance to either the unprecedented technologic and industrial rewards of the nanotechnology or their beneficial human uses. PMID:17185269

  4. Payment for donor kidneys: pros and cons.

    PubMed

    Friedman, E A; Friedman, A L

    2006-03-01

    Continuous growth of the end stage renal disease population treated by dialysis, outpaces deceased donor kidneys available, lengthens the waiting time for a deceased donor transplant. As estimated by the United States Department of Health & Human Services: '17 people die each day waiting for transplants that can't take place because of the shortage of donated organs.' Strategies to expand the donor pool--public relations campaigns and Drivers' license designation--have been mainly unsuccessful. Although illegal in most nations, and viewed as unethical by professional medical organizations, the voluntary sale of purchased donor kidneys now accounts for thousands of black market transplants. The case for legalizing kidney purchase hinges on the key premise that individuals are entitled to control of their body parts even to the point of inducing risk of life. One approach to expanding the pool of kidney donors is to legalize payment of a fair market price of about 40,000 dollars to donors. Establishing a federal agency to manage marketing and purchase of donor kidneys in collaboration with the United Network for Organ Sharing might be financially self-sustaining as reduction in costs of dialysis balances the expense of payment to donors. PMID:16482095

  5. Eduquemos con Musica (Let's Educate with Music).

    ERIC Educational Resources Information Center

    Leiva, Raquel Ojeda

    This elementary and preschool music textbook is designed to reflect Latin America and Caribbean Island cultures and to be useful in both school classrooms and in teacher training courses. Short, easy to learn songs, illustrated pages, and 10 musical games are combined to teach musical forms, rhythm, auditory discrimination, language usage, motor…

  6. Pros and cons of vacuum pressure impregnation

    NASA Astrophysics Data System (ADS)

    Wright, T.

    1981-12-01

    The advantages and disadvantages of using a vacuum pressure impregnation process in the application of insulating varnishes to high voltage electric coils are discussed. The process has the advantages of providing a void free system with high dielectric strength, mechanical resilience, chemical and moisture resistance, and good thermal capabilities. The disadvantages of high cost and large tank size requirements are noted.

  7. [Pros and cons of legalizing marijuana].

    PubMed

    Mönckeberg B, Fernando

    2014-04-01

    There are already several countries that have accepted marijuana as a soft drug, separating it from more dangerous ones. Yarious therapeutic properties have even been attributed to its use. Others, however, think that its use should be prohibited due to the mental interference and behavioral changes produced either by its occasional use as well as the permanent mental damage linked to chronic marijuana use. In order to clarify this divergence of opinions, the scientific literature is reviewed. It is concluded that there is a serious risk, especially for teenagers, associated to chronic marijuana use due to the presence of more frequent psychotic and schizophrenic episodes, which can be permanent, while consumption during pregnancy results in brain damage to the fetus, similar to fetal alcohol syndrome. Scientific research also indicated that smoking marijuana produces an even more severe bronchial damage than tobacco, with risk of lung cancer. In conclusion, the notion that marijuana is a risk-free soft drug is a serious mistake, based on the available conclusive scientific research that shows the opposite. PMID:25697213

  8. McLuhan: Pro and Con.

    ERIC Educational Resources Information Center

    Rosenthal, Raymond, Ed.

    Twenty-one critical essays on the ideas and works of Marshall McLuhan are offered in this review. In the course of the essays, McLuhan is characterized alternately as a genius, an extrapolator, and an oracle; a defender of the choice of choicelessness; a generalizer who rearranges, misinterprets, and misreads the facts to support his theses; an…

  9. [Legalization of drugs--pro and con].

    PubMed

    Marjanović-Cengić, S

    2001-01-01

    This article deals with various opinions and assertions regarding drug legalization. Societal and clinical implication regarding the effect of decrease or increase in the use of psyhoactive substances, on public health, violence and criminal activities have been pointed out. The relation between legal and illegal drugs has been considered. Special attention has been paid to arguments on legalization and decriminalization of marihuana and possible consequences on the risk group-children and adolescents. Experiences from USA and some European countries have been presented. Having in mind the specific situation in BiH, the author of article gives her own view and suggest the introduction of harm reduction strategy into BiH drug policy, without changing the legal drug status. PMID:11769432

  10. Con: Phosphate binders in chronic kidney disease.

    PubMed

    Kestenbaum, Bryan

    2016-02-01

    Phosphate binders are prescribed to chronic kidney disease (CKD) patients based on associations of serum phosphate concentrations with mortality and calcification, experimental evidence for direct calcifying effects of phosphate on vascular smooth muscle tissue and the central importance of phosphate retention in CKD-mineral and bone disorder (CKD-MBD). Current knowledge regarding phosphate metabolism in CKD provides important insight into disease mechanisms and supports future clinical trials of phosphate binders in CKD patients to determine the impact of these medications on clinically relevant outcomes.The risks and benefits of phosphate binders cannot be inferred from association studies of serum phosphate concentrations, which are inconsistent and subject to confounding, animal-experimental data, which are based on conditions that differ from human disease, or physiological arguments, which are limited to known regulatory factors. Many interventions that targeted biochemical pathways suggested by association studies and suspected biological importance have yielded null or harmful results. Clinical trials of phosphate binders are of high clinical and scientific importance to nephrology. Demonstration of reduced rates of clinical disease in such trials could lead to important health benefits for CKD patients, whereas negative results would refocus efforts to understand and treat CKD-MBD. Clinical trials that employ highly practical or 'pragmatic' designs represent an optimal approach for determining the safety and effectiveness of phosphate binders in real-world settings. Absent clinical trial data, observational studies of phosphate binders in large CKD populations could provide important information regarding the benefits, risks and/or unintended side effects of these medications. PMID:26681747

  11. The pros and cons of drug 'trafficking'.

    PubMed

    Stokes, C L

    1995-11-01

    Internalization of targeted therapeutics is often needed for efficacy, but also alters drug penetration of a tissue. A new model explores the trade-offs of intracellular drug trafficking. PMID:7584980

  12. McLuhan: Pro and Con.

    ERIC Educational Resources Information Center

    Rosenthal, Raymond, Ed.

    Twenty-one critical essays on the ideas and works of Marshall McLuhan are offered in this review. In the course of the essays, McLuhan is characterized alternately as a genius, an extrapolator, and an oracle; a defender of the choice of choicelessness; a generalizer who rearranges, misinterprets, and misreads the facts to support his theses; an…

  13. Mandatory Arbitration: Weighing the Pros and Cons

    ERIC Educational Resources Information Center

    Settenbrino, Susan D.

    2012-01-01

    When big businesses enter into mandatory arbitration agreements with consumers, the large companies typically tout the fairness while the individual is left feeling cheated. Now that mandatory arbitration clauses are finding their way into more and more contracts signed by school systems, school boards and district administrators are realizing…

  14. Pros and cons of immunological methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International regulatory agencies Codex Alimentarius, European Commission Regulation and the U.S. Food and Drug Administration have set 20 mg/kg (ppm) as the maximum limit of gluten allowed in foods labeled as “gluten-free”. Immunological approaches appear to be, so far, the most suitable method...

  15. The pros and cons of code validation

    NASA Technical Reports Server (NTRS)

    Bobbitt, Percy J.

    1988-01-01

    Computational and wind tunnel error sources are examined and quantified using specific calculations of experimental data, and a substantial comparison of theoretical and experimental results, or a code validation, is discussed. Wind tunnel error sources considered include wall interference, sting effects, Reynolds number effects, flow quality and transition, and instrumentation such as strain gage balances, electronically scanned pressure systems, hot film gages, hot wire anemometers, and laser velocimeters. Computational error sources include math model equation sets, the solution algorithm, artificial viscosity/dissipation, boundary conditions, the uniqueness of solutions, grid resolution, turbulence modeling, and Reynolds number effects. It is concluded that, although improvements in theory are being made more quickly than in experiments, wind tunnel research has the advantage of the more realistic transition process of a right turbulence model in a free-transition test.

  16. Eduquemos con Musica (Let's Educate with Music).

    ERIC Educational Resources Information Center

    Leiva, Raquel Ojeda

    This elementary and preschool music textbook is designed to reflect Latin America and Caribbean Island cultures and to be useful in both school classrooms and in teacher training courses. Short, easy to learn songs, illustrated pages, and 10 musical games are combined to teach musical forms, rhythm, auditory discrimination, language usage, motor…

  17. Open Admissions: The Pros and Cons.

    ERIC Educational Resources Information Center

    Barzun, Jacques; And Others

    The Council for Basic Education sponsored an all-day symposium on open admissions in 1971. This booklet contains the full text of the addresses given on that occasion, as well as the major part of the discussion among the panelists and answers to questions from the audience. The aim of the symposium was not only to provide information about…

  18. Vacuum assist: angel or demon CON.

    PubMed

    Willcox, Timothy W

    2013-06-01

    Vacuum-assisted venous drainage (VAVD) to enhance venous return during cardiopulmonary bypass (CPB) was described as early as 1958 but was not widely used until the late 1990s. VAVD was initially used to facilitate the use of smaller cannulas with ministernotomy but was increasingly used to allow reduction in CPB circuit size while maintaining CPB flow rates. This innovation was made without planned consideration to CPB circuit design, most critically that of the venous reservoir. Clinical reports of prime reduction facilitated by VAVD in both adult and pediatric CPB were associated with reduced nadir hematocrit and rates of transfusion that encouraged the proliferation of VAVD in CPB. Concomitantly, investigators have reported both in vitro and in vivo significantly increased arterial emboli associated with the use of VAVD, mostly related to accelerated venous air entrainment. In vitro studies continue to confirm this association and likely underestimate the resulting embolic load as a result of flawed study design. While the evidence for VAVD is equivocal, our understanding of the clinical impact of gaseous microemboli in CPB is similarly limited, most likely confined to blood-brain barrier disruption. It is only after two decades that CPB component design is receiving serious attention in terms of air handling. The ethics of innovation in the field of CPB warrant careful consideration. The application of VAVD is not without consequence. PMID:23930383

  19. Con: Weight loss prior to transplant: no.

    PubMed

    Detwiler, Randal K

    2015-11-01

    In large registries of hemodialysis patients, higher body mass index (BMI) is known to be associated with lower mortality rates, while weight loss associates with reduced survival. This so-called 'obesity paradox' includes patients categorized as overweight and obese. Transplantation in the obese patient population has been shown to improve quality of life and reduce mortality when compared with obese recipient candidates remaining on dialysis. Most transplant centers, however, restrict access to transplant based upon predetermined BMI cutoffs. This policy effectively mandates weight loss for many obese transplant candidates. However, BMI, though easily measured, is an inadequate assessment of nutritional status and lean muscle mass in obese patients. Regimens designed to prevent protein-energy wasting may include dietary recommendations and exercise programs that result in favorable changes in body composition without significantly impacting weight. The goal of weight loss is not achievable for many if not most obese dialysis patients. The consequence to the patient is reduced access to life improving transplantation. Patients are forced to pursue dietary, behavioral and possibly surgical interventions to accomplish weight loss despite limited evidence regarding the safety and utility of these interventions. The delay in transplantation also hinders the achievement of improved exercise capacity after successful transplant, a time when weight loss regimens may be safer and more effective. PMID:26359197

  20. Incentives for organ donation: pros and cons.

    PubMed

    Chkhotua, A

    2012-01-01

    Altruism still remains the main principle of organ donation worldwide. However, since the current practices has not met the demand for organs, new strategies should be found to encourage organ donation. Implementation of financial incentives in transplantation is a matter of debate among experts in the fields of transplantation, ethics, law, and economics. It should be acknowledged that donors incur many expenses while participating in the transplant process, which seems unfair. Various forms of incentives have been suggested and are currently used worldwide. This article describes current attitudes toward incentives for in transplantation used in different countries, arguing in favor as well as against them. PMID:22841275

  1. Catálogo de galaxias con núcleo doble

    NASA Astrophysics Data System (ADS)

    Gimeno, G.; Díaz, R. J.; Carranza, G.

    Through systematic inspection of the publications in extragalactic astronomy and galaxy catalogs, we compiled a first list of spiral galaxies with double or multiple nucleus, confirmed and candidates (about 150 objects). This list includes, in its preliminar form, basic data on each object (Names, Coordinates, Redshift, Abs.Mag.B, Major and Minor Axes, Nuclei Separation, IR Properties, Comments, etc.) and for nuclei with apparent separations larger than 1'', it seems complete up to z = 0.0015. This allows us to analize the possible correlations between the geometric and photometric parameters of the double nuclei and the host galaxies, some of which are important, e.g.: nuclei separation vs. absolute magnitude and vs. host galaxy diameter; star formation rate vs. nuclei separation. We also find common global infrared an optical photometric properties that are beeing analized in order to check the validity of some models of galaxies captures and mergers. A subsample of southern objects included in this catalog is beeing observed at Bosque Alegre Astrophysical Station and, up to date, we have performed BVRI photometry and spectroscopy of twelve double or multiple nuclei galaxies.

  2. Weighing the Pros and Cons of TAP

    ERIC Educational Resources Information Center

    Pieczura, Michelle

    2012-01-01

    Headlines offer a plethora of opinions and arguments both for and against proposed and newly implemented teacher evaluation systems all over the United States. Hardly anyone balks at the idea of evaluating teachers, but many question whether these new evaluation systems really improve teaching and learning. The author's experience with the new…

  3. Roofing with Urethane: Pro and Con.

    ERIC Educational Resources Information Center

    Kinzer, Michael; Scott, Gerald P.E.

    1981-01-01

    Gerald Scott's favorable evaluation of the foamed polyurethane roofing system is based on experiences with 55 buildings at Texas A & M. Michael Kinzer, an architect at Colorado State University, disagrees and claims that the system is difficult to install and maintain, and the cost prohibitive. (MLF)

  4. Update on vitamin D: pros and cons.

    PubMed

    Cipriani, Cristiana; Piemonte, Sara; Cilli, Mirella; Pepe, Jessica; Minisola, Salvatore

    2015-01-01

    Controversies on vitamin D currently represent a challenging topic in mineral metabolism research. In particular, current guidelines on vitamin D supplementation did not report consistent recommendation and the issue related to beneficial vs harmful effects of loading vitamin D doses did not lead to any firm universal conclusion. Finally, serum and clinical outcomes of vitamin D supplementation, particularly as far as extra-skeletal effect of the hormone, need to be further investigated. PMID:26811700

  5. Vencemos Con Libros Y La Lengua.

    ERIC Educational Resources Information Center

    Duran, Daniel Flores, Comp.

    The city of Richmond, California has many residents who read and speak only Spanish, and many other Chicanos and Latin Americans who are interested in their heritage. The Service Center Branch of the public library has a collection of books, magazines, and records in Spanish and in English on the problems, history and culture of these people. This…

  6. Investigaccion-accion en la sala de clases sobre las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios y su relacion reciproca con el aprendizaje de las ciencias biologicas

    NASA Astrophysics Data System (ADS)

    Cordova-Santiago, Lizzette Astrid

    La investigacion---accion que se llevo a cabo en la sala de clases tenia como punto de partida las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios para luego examinar sus implicaciones en el proceso de aprendizaje de las Ciencias Biologicas. ¿Que se supone que hagan las creencias en relacion con el aprendizaje? ¿En que consiste incorporar este aspecto a la practica educativa universitaria? Utilizando el modelo de Kemmis y McTaggart (1987) la investigacion-accion se planteo como un proceso dinamico en cuatro momentos en espiral constituidos por la planificacion, la accion, la observacion y la reflexion. Cada una de las fases tuvo una intencion retrospectiva y prospectiva formando una espiral de autorreflexion del conocimiento y la accion. Se llevaron a cabo audio grabaciones en clases y analisis de documentos. Ademas, la profesora-investigadora hizo un portafolio para reflexionar sobre las creencias de la cultura de la ciencia que tienen los estudiantes y las creencias del aprendizaje que tiene la profesora y sobre como la comprension de estos elementos ayudo a mejorar su practica educativa a traves del tiempo. Los resultados obtenidos apuntan a que las creencias de la cultura de la ciencia que tiene el grupo de estudiantes son diversas. Ellos si creen que la ciencia tiene una cultura la cual describieron como: complicada y desconocida que evoluciona constantemente, que es un conjunto de metodos, que es altamente tecnologica, que resuelve problemas de salud, ayuda a interpretar la realidad del mundo que los rodea y su origen y que existen unas intersecciones entre la ciencia y el poder. Sobre las creencias del proceso de aprendizaje de la profesora-investigadora, estas senalan que el modelaje de actores, la vision de la academia que tiene ella asi como la participacion y negociacion entre todos los involucrados en el proceso educativo, son factores que inciden en el proceso de aprendizaje.

  7. Conversations with Marcgrave: the Origin of Modern Astronomy in the Southern Hemisphere (Spanish Title: Conversando con Marcgrave: El Origen de la Astronomía Moderna en el Hemisferio Sur) Conversando Com Marcgrave: a Origem da Moderna Astronomia no Hemisfério Sul

    NASA Astrophysics Data System (ADS)

    Medeiros, Alexandre; Araújo, Fábio

    2005-12-01

    The year 2004 signals the 400th anniversary of the birth of count Mauricio of Nassau, an important character in the history of Brazil. The present text is related to the period of Dutch domination in Pernambuco. The article attempts to rescue the beginnings of Astronomy study in the South hemisphere. Therefore, we idealized a dramatization of a fictitious interview with German astronomer Georg Marcgrave, who was the constructor of the first astronomical observatory in this hemisphere and the author of the first systematic astronomical observations using telescopes in this side of the world. Our "conversation" with Marcgrave is idealized in the old Recife scenario, a place where he lived in Mauricio of Nassau's period and gathers some fellow teachers who love the teaching of Astronomy. The story, this way, is reported in a possibly light and funny atmosphere. Nevertheless, the conceptual and historical framework presented is based on reliable bibliographical sources pointed out at the end of the text. The sources range from the original book of that scientist, in which a solar eclipse is reported, passing through some other classical texts, such as that of Professor Juliano Moreira, up to more recent sources such as the very influential work of professor John North. Other influential texts about the Dutch period in Brazil, such as the classical works of Charles Boxer, Bouman and Boogaart, among others, are also used in the construction of this pedagogical dramatization, which involves an interesting chapter of the history of Astronomy. El año 2004 marca los 400 años del nacimineto del conde Mauricio de Nassau, un importante personaje de la historia del Brasil. El presente texto está relacionado con el período del dominio holandés en Pernambuco. El artículo intenta rescatar los comienzos del estudio de la Astronomía en el hemisferio Sur. Para esto, ideamos una dramatización de una entrevista ficticia con el astrónomo alemán Georg Marcgrave, constructor del primer observatorio astronómico del hemisferio y autor de las primeras observaciones astronómicas sistemáticas utilizando telescopios de este lado del mundo. Nuestra "conversación" con Marcgrave es imaginada en el marco del Recife antiguo, lugar donde él vivió durante el período de Mauricio de Nassau, y reune algunos colegas profesores apasionados por la enseñanza de la Astronomía. La historia es contada, de esta forma, dentro de un clima ameno y hasta un poco divertido, si bien las informaciones históricas y conceptuales contenidas en ella están basadas en fuentes bibliográficas confiables, debidamente referenciadas al final del texto. Estas fuentes van desde la obra original de este científico, en la cual aparece su relato sobre la observación de un eclipse solar en Recife, pasando por obras clásicas respecto de él mismo, como la del profesor Juliano Moreira, hasta fuentes mucho más recientes como el influyente trabajo del profesor John North. Otros textos importantes referidos al período de la colonización holandesa en el Brasil, tales como las obras clásicas de Charles Boxer, Bouman y Boogaart entre otros, son también utilizados en la construcción de esta dramatización pedagógica que se refiere a un interesante capítulo de la Historia de la Astronomía. O ano de 2004 assinala os 400 anos do nascimento do conde Maurício de Nassau, um importante personagem da história do Brasil. O presente texto está relacionado com o período do domínio holandês em Pernambuco. O artigo tenta resgatar o começo do estudo da Astronomia no hemisfério Sul. Para tal, idealizamos uma dramatização de uma entrevista fictícia com o astrônomo alemão Georg Marcgrave, construtor do primeiro observatório astronômico deste hemisfério e autor das primeiras observações astronômicas sistemáticas com o uso de telescópios neste lado do mundo. Nossa "conversa" com Marcgrave é idealizada no cenário do Recife antigo, local em que ele viveu no período de Maurício de Nassau e reúne alguns colegas professores apaixonados pelo ensino da Astronomia. A história é contada, deste modo, em um clima ameno e pretensamente divertido, mas as informações históricas e conceituais nele contidas estão apoiadas em fontes bibliográficas confiáveis devidamente apontadas ao final do texto. Elas vão desde a obra original desse cientista, na qual aparece o seu relato sobre a observação de um eclipse solar no Recife, passando por obras clássicas a seu respeito, como a do professor Juliano Moreira, até fontes bem mais recentes, como o trabalho muito influente do Professor John North. Outros textos de porte sobre o período da colonização holandesa no Brasil, como as obras já clássicas de Charles Boxer, Bouman e Boogaart, dentre outras, são também utilizados na construção desta dramatização pedagógica envolvendo um interessante capítulo da História da Astronomia.

  8. Thermal and electrochemically assisted Pd-Cl bond cleavage in the d9-d9 Pd2dppm2Cl2 complex by Pd3 dppm3COn+ clusters (n = 2, 1, 0).

    TOXLINE Toxicology Bibliographic Information

    Cugnet C; Mugnier Y; Dal Molin S; Brevet D; Lucas D; Harvey PD

    2007-04-16

    A new aspect of reactivity of the cluster [Pd3(dppm)3(micro3-CO)]n+, ([Pd3]n+, n = 2, 1, 0) with the low-valent metal-metal-bonded Pd2(dppm)2Cl2 dimer (Pd2Cl2) was observed using electrochemical techniques. The direct reaction between [Pd3]2+ and Pd2Cl2 in THF at room temperature leads to the known [Pd3(dppm)3(micro3-CO)(Cl)]+ ([Pd3(Cl)]+) adduct and the monocationic species Pd2(dppm)2Cl+ (very likely as Pd2(dppm)2(Cl)(THF)+, [Pd2Cl]+) as unambiguously demonstrated by UV-vis and 31P NMR spectroscopy. In this case, [Pd3]2+ acts as a strong Lewis acid toward the labile Cl- ion, which weakly dissociates from Pd2Cl2 (i.e., dissociative mechanism). Host-guest interactions between [Pd3]2+ and Pd2Cl2 seem unlikely on the basis of computer modeling because of the strong screening of the Pd-Cl fragment by the Ph-dppm groups in Pd2Cl2. The electrogenerated clusters [Pd3]+ and [Pd3]0 also react with Pd2Cl2 to unexpectedly form the same oxidized adduct, [Pd3(Cl)]+, despite the known very low affinity of [Pd3]+ and [Pd3]0 toward Cl- ions. The reduced biproduct in this case is the highly reactive zerovalent species "Pd2(dppm)2" or "Pd(dppm)" as demonstrated by quenching with CDCl3 (forming the well-known complex Pd(dppm)Cl2) or in presence of dppm (forming the known Pd2(dppm)3 d10-d10 dimer). To bring these halide-electron exchange reactions to completion for [Pd3]+ and [Pd3]0, 0.5 and 1.0 equiv of Pd2Cl2 are necessary, respectively, accounting perfectly for the number of exchanged electrons. The presence of a partial dissociation of Pd2Cl2 into the Cl- ion and the monocation [Pd2Cl]+, which is easier to reduce than Pd2Cl2, is suggested to explain the overall electrochemical results. It is possible to regulate the nature of the species formed from Pd2Cl2 by changing the state of charge of the title cluster.

  9. Thermal and electrochemically assisted Pd-Cl bond cleavage in the d9-d9 Pd2dppm2Cl2 complex by Pd3 dppm3COn+ clusters (n = 2, 1, 0).

    PubMed

    Cugnet, Cyril; Mugnier, Yves; Dal Molin, Sophie; Brevet, David; Lucas, Dominique; Harvey, Pierre D

    2007-04-16

    A new aspect of reactivity of the cluster [Pd3(dppm)3(micro3-CO)]n+, ([Pd3]n+, n = 2, 1, 0) with the low-valent metal-metal-bonded Pd2(dppm)2Cl2 dimer (Pd2Cl2) was observed using electrochemical techniques. The direct reaction between [Pd3]2+ and Pd2Cl2 in THF at room temperature leads to the known [Pd3(dppm)3(micro3-CO)(Cl)]+ ([Pd3(Cl)]+) adduct and the monocationic species Pd2(dppm)2Cl+ (very likely as Pd2(dppm)2(Cl)(THF)+, [Pd2Cl]+) as unambiguously demonstrated by UV-vis and 31P NMR spectroscopy. In this case, [Pd3]2+ acts as a strong Lewis acid toward the labile Cl- ion, which weakly dissociates from Pd2Cl2 (i.e., dissociative mechanism). Host-guest interactions between [Pd3]2+ and Pd2Cl2 seem unlikely on the basis of computer modeling because of the strong screening of the Pd-Cl fragment by the Ph-dppm groups in Pd2Cl2. The electrogenerated clusters [Pd3]+ and [Pd3]0 also react with Pd2Cl2 to unexpectedly form the same oxidized adduct, [Pd3(Cl)]+, despite the known very low affinity of [Pd3]+ and [Pd3]0 toward Cl- ions. The reduced biproduct in this case is the highly reactive zerovalent species "Pd2(dppm)2" or "Pd(dppm)" as demonstrated by quenching with CDCl3 (forming the well-known complex Pd(dppm)Cl2) or in presence of dppm (forming the known Pd2(dppm)3 d10-d10 dimer). To bring these halide-electron exchange reactions to completion for [Pd3]+ and [Pd3]0, 0.5 and 1.0 equiv of Pd2Cl2 are necessary, respectively, accounting perfectly for the number of exchanged electrons. The presence of a partial dissociation of Pd2Cl2 into the Cl- ion and the monocation [Pd2Cl]+, which is easier to reduce than Pd2Cl2, is suggested to explain the overall electrochemical results. It is possible to regulate the nature of the species formed from Pd2Cl2 by changing the state of charge of the title cluster. PMID:17371010

  10. Optical and thermal properties of binary calcium phosphate and barium phosphate glasses

    NASA Astrophysics Data System (ADS)

    Lee, E. T. Y.; Taylor, E. R. M.

    2006-02-01

    Binary calcium phosphate and barium phosphate glasses corresponding to xCaO-(100 - x)P2O5 and xBaO-(100 - x)P2O5, respectively, have been prepared in the range of 20 ? x ? 50. Assessment of the optical and thermal properties reveal that refractive index (n) and glass transition temperature (Tg) show a minima while thermal expansion coefficient (?) and thermo-optic coefficient (dn/dT) change monotonically as the amount of modifying oxides, CaO and BaO, increase. ? > 9 × 10-6/°C is required for the calcium phosphate and barium phosphate glasses to exhibit negative dn/dT.

  11. Dependence of the critical cooling rate for lithium-silicate glass on nucleating agents

    NASA Technical Reports Server (NTRS)

    Huang, W.; Ray, C. S.; Day, D. E.

    1986-01-01

    The critical cooling rate, Rc, for glass formation of a glass containing 40 mol pct Li2O and 60 mol pct SiO2, doped with small amounts of Pt, Au, P2O5, and TiO2 nucleating agents, has been measured. Rc increases with increasing Pt and Au additions, but Pt has a larger effect than Au. Additions of P2O5 tend to decrease Rc, whereas TiO2 has practically no effect on Rc. The devitrified glass nucleated with Pt contains only crystalline Li2O-SiO2, but all the other devitrified glasses, including the undoped glass, contain both Li2O-SiO2 and Li2O-2SiO2. Analysis shows that Rc increases as the concentration of the Li2O-SiO2 phase in the devitrified glass increases.

  12. Silver doped nanobioactive glass particles for bone implant applications

    NASA Astrophysics Data System (ADS)

    Prabhu, M.; Kavitha, K.; Karunakaran, G.; Manivasakan, P.; Rajendran, V.

    2013-02-01

    Silica based silver doped nanobioactive glass compositions (58SiO2-33CaO-9P2O5 and 58SiO2-23CaO-9P2O5-10Ag2O(mol%)) were synthesized by a simple sol-gel route. The prepared samples were comprehensively characterised by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopic studies. The results reveal that the prepared samples have amorphous phase with spherical morphology and having a particle size less than 100 nm. The specific surface areas were 90 and 61 m2g-1 respectively. The in vitro bioactivity of glass samples were confirmed by the formation of hydroxyapatite layer on glass surfaces. The Ag2O-doped nanobioactive glasse samples shows reveal significant antibacterial activity compare with base glasses.

  13. The nature of the Ailao Shan-Red River (ASRR) shear zone: Constraints from structural, microstructural and fabric analyses of metamorphic rocks from the Diancang Shan, Ailao Shan and Day Nui Con Voi massifs

    NASA Astrophysics Data System (ADS)

    Liu, Junlai; Tang, Yuan; Tran, My-Dung; Cao, Shuyun; Zhao, Li; Zhang, Zhaochong; Zhao, Zhidan; Chen, Wen

    2012-03-01

    The structural geology, timing of shearing, and tectonic implications of the ASRR shear zone, one of the most striking lineaments in Southeast Asia, have been the topics of extensive studies over the past few decades. The Xuelong Shan (XLS), Diancang Shan (DCS), Ailao Shan (ALS) and Day Nui Con Voi (DNCV) metamorphic massifs along the shear zone have preserved important information on its structural and tectonic evolution. Our field structural analysis, detailed microstructural and fabric analysis, as well as the quartz, sillimanite and garnet fabric studies of the sheared rocks from the massifs demonstrate the dominant roles of three deformation episodes during Cenozoic tectonic evolution in the shear zone. Among the contrasting structural and microstructural associations in the shear zone, D2 structures, which were formed at the brittle to ductile transition during large-scale left-lateral shearing in the second deformation episode, predominate over the structural styles of the other two deformation episodes. Discrete micro-shear zones with intensive grain size reduction compose the characteristic structural style of D2 deformation. In addition, several types of folds (early shearing folds, F21, and late-shearing folds, F22) were formed in the sheared rocks, including discrete to distributed mylonitic foliation, stretching lineation and shear fabrics (e.g., mica fish, domino structures, as well as sigma and delta fabrics). A sequence of microstructures from syn-kinematic magmatic flow, high-temperature solid-state deformation, to brittle-ductile shearing is well-preserved in the syn-kinematic leucocratic intrusions. Deformation structures from the first episode (D1) are characterized by F1 folds and distributed foliations (S1) in rocks due to pure shearing at high temperatures. They are preserved in weakly sheared (D2) rocks along the eastern margin of the ALS belt or in certain low-strain tectonic enclaves within the shear zone. Furthermore, semi-brittle deformation structures, such as hot striae and discrete retrogression zones, are attributed to normal-slip shearing in the third deformation episode (D3), which was probably locally active, along the eastern flank of the DCS range, for example. There are four quartz c-axis fabric patterns in the mylonitic rocks, including type A point maxima, type B Y point maxima with crossed girdles superimposition, type C quadrant maxima, as well as type D point and quadrant maxima combination. They are consistent with microscopic observations of microstructures of high-temperature pure shearing, low-temperature simple shearing and their superimposition. Integrated microstructural analysis and fabric thermometer studies provide information on both high temperature (up to 750 °C) and dominant low-temperature (300-600 °C) deformations of quartz grains in different rock types. Sillimanite and garnet fabrics, especially the latter, were primarily formed at the peak metamorphism during high-temperature pure shearing. The above structural, microstructural and fabric associations were generated in the tectonic framework of the Indian-Eurasian collision. The low-temperature microstructures and fabrics are attributed to left-lateral shearing along the ASRR shear zone from 27 to 21 Ma during the southeastward extrusion of the Indochina block, which postdated high-temperature deformation at the peak metamorphism during the collision.

  14. Late Proterozoic diabase dikes of the New Jersey Highlands; a remnant of Iapetan rifting in the north-central Appalachians

    USGS Publications Warehouse

    Volkert, R.A.; Puffer, J.H.

    1995-01-01

    Diabase dikes of widespread occurrence intrude only middle Proterozoic rocks in the New Jersey Highlands. These dikes are enriched in TiO2, P2O5, Zr, and light rare earth elements, and have compositions that range from tholeiitic to alkalic. Dike descriptions, field relations, petrography, geochemistry, petrogenesis, and tectonic setting are discussed. The data are consistent with emplacement in a rift-related, within-plate environment and suggest a correlation with other occurrences of late Proterozoic Appalachian basaltic magmatism.

  15. Petrogenesis of high-phosphorous Wishstone Class rocks in Gusev Crater, Mars

    NASA Astrophysics Data System (ADS)

    Usui, Tomohiro; McSween, Harry Y.; Clark, Benton C.

    2008-12-01

    The Spirit rover has analyzed a wide variety of alkaline volcanic rocks in Gusev Crater. Among them are Wishstone Class tephrites with unusually high P2O5 (>5 wt %) abundances. To obtain the chemical compositions of rock interiors, we extrapolated a trend defined by brushed and abraded surface compositions. The extrapolation analysis suggests the high-P2O5 tephrite signature is not attributable to secondary aqueous alteration but represents an igneous rock composition. Assessment of the compositional trend also suggests that merrillite is the phosphate mineral in Wishstone Class. Modified CIPW norm calculations using merrillite instead of apatite show that Wishstone Class rocks are silica saturated (hypersthene-olivine normative) and alkaline. The high-P2O5 whole rock compositions plot above solubility curves of merrillite in a diagram of P2O5 versus aluminosity, suggesting that mechanical admixture of merrillite is required. A source supplying merrillite cannot be a common silicate magma; instead, it could be a carbonatitic melt or a highly fractionated residual melt (jotunite) after anorthosite crystallization. Comparison with Earth analogs suggests that the Wishstone Class is akin to alkaline basalts in the eastern Snake River Plain, with regard to its chemistry, texture, and geologic context. These alkaline basalts are interpreted to originate from mantle metasomatized by CO2-fluids and highly alkaline melts in the wake of the Yellowstone hot spot. Thus, we propose that the Wishstone Class represents a silica-saturated alkaline suite that has mechanically mixed xenocrystic merrillites, probably during explosive volcanic eruption; the merrillites crystallized from carbonate-rich magma produced by melting of a CO2-bearing Martian mantle.

  16. The geology of the Florida land-pebble phosphate deposits

    USGS Publications Warehouse

    Cathcart, J.B.; Blade, L.V.; Davidson, D.F.; Ketner, K.B.

    1952-01-01

    The land-pebble phosphate district is on the Gulf Coastal Plain of Florida. The phosphate deposits are in the Bone Valley formation, dated Pliocene by most writers. These strata overlie the Miocene Hawthorn formation and are overlain by consolidated sands 3 to 20 feet thick. The minable phosphate deposits, called “matrix” in the district, range from a featheredge to about 50 feet in thickness and consist of phosphatic pellets and nodules, quartz sand, and montmorillonitic clay in about equal proportions. Locally the matrix displays cross-bedding and horizontal laminations, but elsewhere it is structureless. The phosphorite particles, composed largely of carbonate-fluorapatite, range in diameter from less than 0.1 mm to about 60 cm and in P2O5 content from 30 to 36 percent. Coarse-pebble deposits, containing 30 to 34 percent P2O5 are found mainly on basement highs; and fine-pebble deposits, containing 32 to 36 percent P2O5 are, are found in basement lows. Deposits in the northern part of the field contain more phosphate particles and their P2O5 content is higher than those in the southern part. The upper part of the phosphatic strata is leached to an advanced degree and consists of quartz sand and clay-sized particules of pseudowavellite and wavellite. The leached zone ranges in thickness from a featheredge to 60 feet. The origin of the land-pebble deposits is incompletely known. Possible modes of origin are a residuum of Miocene age, or a reworked residuum of Pliocene or Quaternary age.

  17. Application of multivariate statistical analyses in the interpretation of geochemical behaviour of uranium in phosphatic rocks in the Red Sea, Nile Valley and Western Desert, Egypt.

    PubMed

    El-Arabi, Abd El-Gabar M; Khalifa, Ibrahim H

    2002-01-01

    Factor and cluster analyses as well as the Pearson correlation coefficient have been applied to geochemical data obtained from phosphorite and phosphatic rocks of Duwi Formation exposed at the Red Sea coast. Nile Valley and Western Desert. Sixty-six samples from a total of 71 collected samples were analysed for SiO2, TiO2, Al203, Fe2O3, CaO, MgO, Na2O, K2O, P2O5, Sr, U and Pb by XRF and their mineral constituents were determined by the use of XRD techniques. In addition, the natural radioactivity of the phosphatic samples due to their uranium, thorium and potassium contents was measured by gamma-spectrometry. The uranium content in the phosphate rocks with P2O5 > 15% (average of 106.6 ppm) is higher than in rocks with P2O5 < 15% (average of 35.5 ppm). Uranium distribution is essentially controlled by the variations of P2O5 and CaO, whereas it is not related to changes in SiO2, TiO2, Al2O3, Fe2O3, MgO, Na2O and K2O concentrations.-Factor analysis and the Pearson correlation coefficient revealed that uranium belaves geochemically in different ways in the phosphatic sediments and phosphorites in the Red Sea, Nile Valley and Western Desert. In the Red Sea and Western Desert phosphorites, uranium occurs mainly in oxidized U6+ state where it seems to be fixed by the phosphate ion, forming secondary uranium phosphate minerals such as phosphuranylite. In the Nile Valley phosphorites, ionic substitution of Ca2+ by U4 is the main controlling factor in the concentration of uranium in phosphate rocks. Moreover, fixation of U6- by phosphate ion and adsorption of uranium on phosphate minerals play subordinate roles. PMID:12066979

  18. Energy transfer upconversion on neodymium doped phosphate glasses investigated by Z-scan technique

    NASA Astrophysics Data System (ADS)

    Lima, W. J.; Martins, V. M.; Monte, A. F. G.; Messias, D. N.; Dantas, N. O.; Bell, M. J. V.; Catunda, T.

    2013-07-01

    Time-resolved Z-scan measurements were employed to characterize energy transfer upconversion on the phosphate glass matrix, named PAN (P2O5-Al2O3-Na2CO3), doped with increasing Nd3+ concentrations. It was observed a linear dependence of the upconversion parameter with the dopant agent, which indicates the presence of a static and dynamic energy transfer processes. The critical inversion density was also evaluated for the same set of samples.

  19. Ionic conductivity and glass transition of phosphoric acids

    SciTech Connect

    Wang, Yangyang; Lane, Nathan A; Sun, Che-Nan; Fan, Fei; Zawodzinski, Thomas; Sokolov, Alexei P

    2013-01-01

    Here we report the low-temperature dielectric and viscoelastic properties of phosphoric acids in the range of H2O:P2O5 1.5 5. Both dielectric and viscosity measurements allow us to determine the glass-transition temperatures of phosphoric acids. The obtained glass-transition temperatures are in good agreement with previous differential scanning calorimetric measurements. Moreover, our analysis reveals moderate decoupling of ionic conductivity from structural relaxation in the vicinity of the glass transition.

  20. Ionic Ckonductivity and Glass Transition of Phosphoric Acids

    SciTech Connect

    Wang, Yangyang; Lane, Nathan A; Sun, Che-Nan; Fan, Fei; Zawodzinski, Thomas; Sokolov, Alexei P

    2013-01-01

    Here we report the low-temperature dielectric and viscoelastic properties of phosphoric acids in the range of H2O:P2O5 1.5 5. Both dielectric and viscosity measurements allow us to determine the glass-transition temperatures of phosphoric acids. The obtained glass-transition temperatures are in good agreement with previous differential scanning calorimetric measurements. Moreover, our analysis reveals moderate decoupling of ionic conductivity from structural relaxation in the vicinity of the glass transition.

  1. Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

    NASA Technical Reports Server (NTRS)

    Campbell, J. E.

    1973-01-01

    The thermal inactivation curve for Bacillus subtilis var. niger spores on the Viking lander is examined. Tests were conducted at 113 C and 25% RH, and over a wide range of temperatures using .001% RH and additions of P2O5 to dry the environment. Results show the 25% RH environment did not significantly reduce the survival curve, while the survival curves for spores treated under the drier .001% RH environment was reduced by a factor of 3.

  2. Luna 24 origins - Some trace element constraints

    NASA Technical Reports Server (NTRS)

    Jovanovic, S.; Jensen, K. J.; Reed, G. W., Jr.

    1978-01-01

    Luna 24 basaltic material originated in the particular volume of the lunar crust that produced Apollo 11 and Luna 16 basaltic material; it has the same Clr/P2O5 (r = residual) signature. Ru-Os contents (Barsukov et al., 1977) and a number of radiogenic age measurements place Luna 24 basalt origins stratigraphically in a layer between those from which Apollo 15 and Apollo 11 and 17 basalts were derived.

  3. The Meanings of Astronomical Observation: An Analysis on the Basis of Relationship with Knowledge. (Spanish Title: Los Sentidos de la Observación Astronómica: un Análisis sobre la Base de la Relación con el Saber.) Os Sentidos da Observação Astronômica: Uma Análise com Base na Relação com o Saber

    NASA Astrophysics Data System (ADS)

    Klein, Alberto Eduardo; de Mello Arruda, Sergio; Meneghello Passos, Marinez; Vinicius Domenes Zapparoli, Ferdinando

    2010-12-01

    This article presents results of a research which aimed to understand the meanings that people construct for astronomical observation. The subjects, students and school teachers, initially received some instruction on how to view astronomical objects through the telescope. After the observation was realized, they were interviewed. The data analysis allowed the creation of 12 categories, later interpreted on the basis of relationship with knowledge (relation to the world, with himself and with others), as presented by Bernard Charlot. Este artículo presenta los resultados de una investigación que tuvo como objetivo comprender los sentidos que las personas construyen para la observación astronómica. Los sujetos, los estudiantes y maestros de escuela, recibieron inicialmente algunas instrucciones sobre cómo ver los objetos astronómicos a través del telescopio. Al término de la observación, fueron entrevistados. El análisis de datos permitió la creación de 12 categorías que más tarde fueron interpretadas sobre la base de la relación con el conocimiento (relación con el mundo, consigo mismo y con los demás), tal como presentado por Bernard Charlot. Este artigo apresenta resultados de uma pesquisa que objetivou entender quais os sentidos que as pessoas constroem para a observação astronômica. Os sujeitos da pesquisa, estudantes e professores do ensino médio, receberam inicialmente alguma instrução sobre como visualizar os objetos astronômicos através do telescópio. Após a realização da observação, eles foram entrevistados. A análise dos dados permitiu a elaboração de 12 categorias que foram posteriormente interpretadas com base nas relações com o saber (relação com o mundo, consigo mesmo e com o outro), conforme apresentadas por Bernard Charlot.

  4. Phosphatic Permian rocks of the Adobe Range, Nevada, and their environment of deposition

    USGS Publications Warehouse

    Ketner, Keith Brindley

    1979-01-01

    Permian sedimentary rocks in the Adobe range, northern Nevada, are phosphatic, and although the particles of phosphate are relatively more disseminated, they closely resemble the rocks of the Phosphoria Formation. In the northern Adobe Range, where the entire Permian sequence is approximately correlative with the Phosphoria Formation, it is 200 m thick and averages 1.7 percent P2O5 . In the southern Adobe Range, the Permian sequence is more than 1,700 m thick, and the upper half which is roughly correlative with the Phosphoria Formation averages more than 2 percent P2O5. Some thin beds in rocks of Permian age contain more than 20 percent P2O5. Phosphatic rocks of the Adobe Range were deposited in shallow water among islands in the western part of the epicontinental Phosphoria sea. The continental margin and the open ocean lay far to the west. At the same time, the Phosphoria Formation was being deposited in the eastern and central parts of the Phosphoria sea. Theories based on the work of Kasakov done in 1937 relating phosphate deposition directly to sites of upwelling oceanic waters are questioned. Nondeposition of diluent materials such as detritus and carbonate is probably of more importance in producing phosphate in economic concentrations than is geographic position with respect to upwelling waters.

  5. on the Crystallization Behaviors of Ti-Bearing Blast Furnace Slags Using Single Hot Thermocouple Technique

    NASA Astrophysics Data System (ADS)

    Sun, Yongqi; Li, Jing; Wang, Xidong; Zhang, Zuotai

    2014-08-01

    The present paper investigates how the P2O5 addition influences the crystallization behaviors of Ti-bearing blast furnace (Ti-BF) slags with different basicity using Single Hot Thermocouple Technique. It was found that the basicity showed a significant effect on the crystallization behaviors of the Ti-BF slags, and the trend of formation of the rod-shape crystal decreased while the trend of formation of dendrite crystal increased with increasing basicity. The addition of P2O5 was found to promote the formation of rod-shape crystal. The basicity and crystallization temperature that the rod-shape crystal could be formed increased, while the incubation time of formation of the rod-shape crystal decreased with increasing P2O5 content. Scanning electron microscope equipped with energy-dispersive X-ray spectroscope and X-ray diffraction were employed to observe the morphology and determine the crystalline phase of the Ti-enriched crystals. The results indicated that the rod-shape crystal was rutile. The kinetics of the formation of rutile was studied, and the mechanism of crystallization and growth was further discussed. The results indicated that the crystallization of rutile was one-dimensional interface-controlled growth, and the nucleation rate varied with the holding time.

  6. Raman scattering characteristics of the TBSN-based tellurite glass system as a new Raman gain medium

    NASA Astrophysics Data System (ADS)

    Jose, Rajan; Arai, Yusuke; Ohishi, Yasutake

    2007-07-01

    A study was initiated to understand requirements for widening and flattening the gain spectra of tellurite-based glasses for their application as new gain media for photonic devices. For this purpose, two Raman active components, WO3 and P2O5, were added either separately or jointly to a TeO2-BaO-SrO-Nb2O5 (TBSN) glass system, and the Raman spectral evolution in response to this addition was studied. Raman scattering cross sections of the TBSN glasses were increased with an increase in the WO3 content and decreased with an increase in the P2O5 content. The Raman intensity and bandwidth increased when WO3 and P2O5 were jointly added in TBSN. The bandwidths of the Raman gain coefficient spectra of the present tellurite glasses were more than twice that of a conventional TeO2-Bi2O3-ZnO-Na2O glass and 70% larger than that of silica glass. The new glasses are expected to be candidates for ultrabroadband fiber Raman amplifiers.

  7. Structural characterization of some sol-gel derived phosphosilicate glasses

    NASA Astrophysics Data System (ADS)

    Todan, L.; Anghel, E. M.; Osiceanu, P.; Turcu, R. V. F.; Atkinson, I.; Simon, S.; Zaharescu, M.

    2015-04-01

    A comparative study of three phosphosilicate gels of the 90SiO2-10P2O5 composition obtained from tetraethoxysilane and three phosphorous precursors: triethylphosphate (TEP), triethylphosphite (TEPI) and H3PO4 is performed. 29Si and 31P Magic Angle Spining NMR, X-ray Photoelectron, X-ray Fluorescence and Raman spectroscopies as well as TG analysis are used in order to establish phosphorous precursors and annealing influence on composition and structure of the outcome materials. Unlike the three dimensional silicate network made of Si(OSi)x(OH)4-x species, unreacted TEP (100% Q1 condensed phosphorous units) from TEP derived gel and a large amount of isolated phosphorous species (39.7% Q0) in the H3PO4 derived gel are identified. Annealing at 700 °C of the three gels give similar structure with the 90SiO2-10P2O5 glass, excepting the triethylphosphate derived glass that has a much lower P content. Thus, the H3PO4 derived glass at 700 and 1000 °C shows 1.89 and 1.94 times higher P2O5/SiO2 ratios than in the case of the TEP derived one.

  8. Raman and X-ray absorption spectroscopy studies of chromium-phosphorus interactions in high-bismuth high-level waste glasses

    NASA Astrophysics Data System (ADS)

    McKeown, David A.; Gan, Hao; Pegg, Ian L.

    2014-09-01

    High-level waste (HLW) glasses containing bismuth, phosphorus, and chromium were investigated using Raman and X-ray absorption spectroscopy (XAS). The novel and practically important occurrence of foaming on cooling of these melts is associated with P and Cr from the HLW. In response, glasses were synthesized where Bi2O3 and P2O5 contents were varied independently. Relationships between P and Cr were found, where as P2O5-content increases, chromate Cr-O stretch Raman modes diminish intensity, while Cr XAS shows that Cr reduces, from 50% Cr6+ + 50% Cr3+ to nearly 20% Cr6+ + 80% Cr3+, explaining the chromate mode behavior. In the most P2O5-rich glass, the chromate Cr-O distance increases by approximately 0.10 Å, which may indicate bonding between CrO4 and PO4 tetrahedra, similar to that in chromo-phosphates. The presence of chromo-phosphate domains in HLW melts can be linked to oxygen generation as a source of the foaming.

  9. Study on the preparation and properties of silver-doped phosphate antibacterial glasses (Part I)

    NASA Astrophysics Data System (ADS)

    Ahmed, A. A.; Ali, A. A.; Mahmoud, Doaa A. R.; El-Fiqi, A. M.

    2011-05-01

    Silver-doped phosphate antibacterial glasses were prepared by the melting method. The antibacterial effects of some undoped and silver-doped glasses of compositions 65P 2O 5-10CaO-(25- x) Na 2O, 70P 2O 5-20CaO-(10- x) Na 2Oand (70- x) P 2O 5-30CaO, (where x = 0, 0.5, 1.2 Ag 2O), against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli micro-organisms using agar disk-diffusion assays were investigated. The structures of some glasses were studied by XRD, FT-IR, and UV-VIS spectroscopy. The variation of pH with dissolution rate was studied. The tested silver-free and silver-doped glasses demonstrated different antibacterial effects against the tested micro-organisms. For silver-free glasses, an increase in inhibition zone diameter (zone of no bacterial growth) was seen with the decrease in water pH. Silver-doped glasses showed an increase in inhibition zone diameter with increasing Ag 2O content. The low pH produced by glass dissolution was certainly a critical factor for glass antibacterial effect. The more the phosphate ions released the lower is the pH and the greater the antibacterial effect.

  10. A density functional theory study of structural, mechanical and electronic properties of crystalline phosphorus pentoxide.

    PubMed

    Ainsworth, Richard I; Di Tommaso, Devis; de Leeuw, Nora H

    2011-12-21

    Quantum mechanical calculations of single crystal phosphorus pentoxide (P(2)O(5)) have been conducted using the plane-wave ultrasoft pseudopotential technique based on the density functional theory (DFT), in the generalized gradient approximation, with dispersive correction (DFT-D). The implementation of the dispersive correction is shown to improve significantly the structural agreement with experiment, compared to standard plane-wave DFT. The second order elastic constants for the o'(P(2)O(5))(∞) and o(P(2)O(5)) orthorhombic phases were obtained from a polynomial fit to the calculated energy-strain relation. Both phases are shown to be highly elastically anisotropic due to structural features. Polycrystalline aggregate properties have been evaluated to give complete mechanical descriptions. Further investigation of the electronic band structure and density of states has been completed. Analysis of the complex chemical bonding has been carried out using Löwdin atomic charge and valence charge density data showing mixed ionic and covalent character in both phases. PMID:22191892

  11. Structural and luminescence study on titanium doped lead manganese borophosphate glass

    NASA Astrophysics Data System (ADS)

    Leow, T. Q.; Eeu, T. Y.; Leong, P. M.; Pang, X. G.; Hussin, R.

    2013-05-01

    A series of lead manganese borophophate glass samples were prepared and studied to determine the structural and luminescence properties using Fourier Transform Infrared Spectroscopy (FT-IR) and Photoluminescence Spectrophotometer. The glass samples with composition of 20PbO-xMnO2-30B2O3-(50-x)P2O5-2TiO2 where 0 ? x ? 20 were prepared using melt-quenching technique in air atmosphere. The samples containing different MnO2 and P2O5 content were both subjected to FT-IR testing to show the contrary effects of the network modifier. Infrared absorption spectrum shows vibrational bands of BO4 and PO3 structure within the borophosphate network structure, with the dominant BO units increasing with lower P2O5 mol%. All glassy samples exhibit photoluminescence emission in the visible range. Manganese contained samples shows violet emissions while those without show violet-blue emission when excited by UV.

  12. Characteristics of solid-state batteries with zinc/cadmium halide-doped silver phosphate glasses as electrolytes

    NASA Astrophysics Data System (ADS)

    Das, S. S.; Baranwal, B. P.; Gupta, C. P.; Singh, Punita

    Several samples of ion-conducting silver phosphate glasses doped with zinc/cadmium halides are prepared and subjected to X-ray diffraction analysis, transference number measurement, and electrical conductivity studies. The percentage transference numbers of these glasses are found to lie between 98.3 and 99.3, which suggests that the glasses are essentially ionic conductors. The conductivity values range from 1.66×10 -2 to 8.66×10 -2 S cm -1 at 300 °C. Solid-state batteries using these glassy systems as electrolytes with the cell configurations Ag||Ag 2O?P 2O 5?(20%)Zn/CdX 2||(C+I 2) and Ag||Ag 2O?P 2O 5?(20%)Zn/CdX 2||(C+I 2+electrolyte) (where X is Cl, Br or I) have been fabricated and their discharge characteristics studied. Cells with undoped silver phosphate glasses as electrolytes have also been prepared and studied. The addition of Zn/CdX 2 to silver phosphate glass results in a substantial increase in the open-circuit voltage in the order MI 2>MBr 2>MCl 2 (where M is the dopant cation). Cells with Ag||Ag 2O?P 2O 5?(20%)Zn/CdI 2||(C+I 2+electrolyte) deliver the best performance.

  13. Estudio de la fotoabsorción y fotoionización de la molécula de alta relevancia atmosférica no a través de los estados Rydberg con la metodología MQDO

    NASA Astrophysics Data System (ADS)

    Bustos, E.; Velasco, A. M.; Martín, I.; Lavín, C.

    Los procesos de fotoionización son de una importancia fundamental [1] y encuentran aplicación en un gran número de contextos científicos: Astrofísica [2], química de las radiaciones, biología. Los investigadores de dichos campos, necesitan de valores de fiables de secciones eficaces para la fotoionización parcial, la Fotoabsorción, así como para los procesos de fotofragmentación en amplios intervalos espectrales, particularmente en estudios de modelización [3-5]. En este trabajo se ha centrado la atención sobre el oxido nítrico, que se ha considerado apropiado y relevante por varios motivos: por el trascendental papel que representa en la física y química de la alta atmosfera [6], aparte de por estar íntimamente relacionado con los problemas de contaminación. Los procesos de recombinación disociativa [7] del NO, donde los estados Rydberg se encuentran directamente implicados, son relevantes, por ejemplo, en las regiones E y F de la ionosfera [7]. En este trabajo se estudia la fotoionización del NO desde el estado fundamental con la versión molecular del método del orbital de defecto cuántico (MQDO). Para ello se calcula el diferencial de las fuerzas de oscilador parciales que constituyen los canales de fotoionización del NO desde el estado fundamental. La continuidad del diferencial de fuerza de oscilador calculada a través del umbral de fotoionización, esto es, en las regiones del espectro discreta y del continua, se adopta como criterio de calidad la escasez de datos comparativos [8].

  14. Online Formative Assessment in Higher Education: Its Pros and Cons

    ERIC Educational Resources Information Center

    Baleni, Zwelijongile Gaylard

    2015-01-01

    Online and blended learning have become common educational strategy in higher education. Lecturers have to re-theorise certain basic concerns of teaching, learning and assessment in non-traditional environments. These concerns include perceptions such as cogency and trustworthiness of assessment in online environments in relation to serving the…

  15. Cons and pros of female anesthesiologists: Academic versus nonacademic

    PubMed Central

    Shams, Tarek; El-Masry, Ragaa

    2015-01-01

    Background and Aims: We hypothesized that “Feminization” of medicine has an impact on the choice of anesthesiology as a specialty. However anesthesiology is still not a more popular choice among women in medicine. We aimed to evaluate the implications of anesthesiology as a profession on personal and family life of women anesthesiologists; the differences between academic and nonacademic women anesthesiologists with respect to these effects and the effect of women anesthesiologists on the profession. Materials and Methods: This study surveyed a total of 46 woman anesthesiologists; both academic and nonacademic institutions in our country between January and May 2013. A convenient sampling method was used. A constructed self-reported questionnaire was developed to explore the 29 items of woman-anesthesiology-related implications (family, personal, and job), in the form of close-ended questions. Results: Negative implications of anesthesiology on personal and family life of woman were common. With the exception of financial limitation, academic group was significantly more affected. Increased surgeons conflict (98%), poor surgeon acceptance (87%), poor patient acceptance and recurrent change of work schedule (80% each) were the most common perceived negative impacts of women in the field of anesthesiology. Some positive implications were perceived as independent, positive social interaction, empowerment, soothing work environment, emotional reaction to patient complaint, and increased perfectionism (nearly 94%, 98%, 87%, 91%, 89%, and 76%, respectively). Conclusion: Serious implications exist for the personality and family life of women who chose anesthesiology as a specialty and career, and most of these implications were significantly more prevalent among women with an academic career. Furthermore, anesthesiology as a profession was significantly affected by women joining the department. PMID:25788779

  16. Encompassing Sexual Medicine within Psychiatry: Pros and Cons

    ERIC Educational Resources Information Center

    Segraves, Robert Taylor

    2010-01-01

    Objective: This article examines the positive and negative aspects of psychiatry encompassing sexual medicine within its purview. Methods: MEDLINE searches for the period between 1980 to the present were performed with the terms "psychiatry," "sexual medicine," and "sexual dysfunction." In addition, sexual medicine texts were reviewed for chapters…

  17. Communication Technology: Pros and Cons of Constant Connection to Work

    ERIC Educational Resources Information Center

    Diaz, Ismael; Chiaburu, Dan S.; Zimmerman, Ryan D.; Boswell, Wendy R.

    2012-01-01

    We examined the relationship between employees' attitudes related to communication technology (CT) flexibility, communication technology (CT) use, work-to-life conflict and work satisfaction. Based on data obtained from 193 employees, CT flexibility predicted more CT use. Further, CT use was associated not only with increased work satisfaction,…

  18. Astrobiological Aspects of Mars and Human Presence: Pros and Cons

    PubMed Central

    Horneck, G

    2008-01-01

    After the realization of the International Space Station, human exploratory missions to Moon or Mars, i.e. beyond low Earth orbit, are widely considered as the next logical step of peaceful cooperation in space on a global scale. Besides the human desire to extend the window of habitability, human exploratory missions are driven by several aspects of science, technology, culture and economy. Mars is currently considered as a major target in the search for life beyond the Earth. Understanding the history of water on Mars appears to be one of the clues to the puzzle on the probability of life on Mars. On Earth microorganisms have flourished for more than 3.5 Ga and have developed strategies to cope with so-called extreme conditions (e.g., hot vents, permafrost, subsurface regions, rocks or salt crystals). Therefore, in search for life on Mars, microorganisms are the most likely candidates for a putative biota on Mars and the search for morphological or chemical signatures of life or its relics is one of the primary and most exciting goals of Mars exploration. The presence of humans on the surface of Mars will substantially increase this research potential, e.g., by supporting deep subsurface drilling and by allowing intellectual collection and sophisticated in situ analysis of samples of astrobiological interest. On the other hand, such long-duration missions beyond LEO will add a new dimension to human space flight, concerning the distance of travel, the radiation environment, the gravity levels, the duration of the mission, and the level of confinement and isolation the crew will be exposed to. This will raise the significance of several health issues, above all radiation protection, gravity related effects as well as psychological issues. Furthermore, the import of internal and external microorganisms inevitably accompanying any human mission to Mars, or brought purposely to Mars as part of a bioregenerative life support system needs careful consideration with regard to planetary protection issues. Therefore, before planning any human exploratory mission, the critical issues concerning human health and wellbeing as well as protection of Mars in its pristine condition need to be investigated. PMID:19048093

  19. The Pros & Cons of Teaching/Learning by Television.

    ERIC Educational Resources Information Center

    Weber, Andrew M.

    Learning by television is not a new phenomenon and, as an educational medium, it has gone through some severe growing pains. Unfortunately, while advances in technologies (cable, home recorders, satellites, teleconferencing) have contributed to an increase in the number of telecourses since the mid-1970s, faculty are often unprepared to teach…

  20. Astrobiological aspects of Mars and human presence: pros and cons.

    PubMed

    Horneck, G

    2008-08-01

    After the realization of the International Space Station, human exploratory missions to Moon or Mars, i.e. beyond low Earth orbit, are widely considered as the next logical step of peaceful cooperation in space on a global scale. Besides the human desire to extend the window of habitability, human exploratory missions are driven by several aspects of science, technology, culture and economy. Mars is currently considered as a major target in the search for life beyond the Earth. Understanding the history of water on Mars appears to be one of the clues to the puzzle on the probability of life on Mars. On Earth microorganisms have flourished for more than 3.5 Ga and have developed strategies to cope with so-called extreme conditions (e.g., hot vents, permafrost, subsurface regions, rocks or salt crystals). Therefore, in search for life on Mars, microorganisms are the most likely candidates for a putative biota on Mars and the search for morphological or chemical signatures of life or its relics is one of the primary and most exciting goals of Mars exploration. The presence of humans on the surface of Mars will substantially increase this research potential, e.g., by supporting deep subsurface drilling and by allowing intellectual collection and sophisticated in situ analysis of samples of astrobiological interest. On the other hand, such long-duration missions beyond LEO will add a new dimension to human space flight, concerning the distance of travel, the radiation environment, the gravity levels, the duration of the mission, and the level of confinement and isolation the crew will be exposed to. This will raise the significance of several health issues, above all radiation protection, gravity related effects as well as psychological issues. Furthermore, the import of internal and external microorganisms inevitably accompanying any human mission to Mars, or brought purposely to Mars as part of a bioregenerative life support system needs careful consideration with regard to planetary protection issues. Therefore, before planning any human exploratory mission, the critical issues concerning human health and wellbeing as well as protection of Mars in its pristine condition need to be investigated. PMID:19048093

  1. Pros and cons of organ shielding for CT imaging.

    PubMed

    Samei, Ehsan

    2014-10-01

    With the increased importance of CT radiation dose to health care providers, patients and the general public, there is an increased responsibility to minimize patient dose effectively. Bismuth shields offer a simple strategy to reduce dose to certain anterior radiosensitive organs such as breasts and eyes. However, in order to reduce organ dose they must be used properly; improper use can lead to an actual increase in the patient dose. They also create a proportional increase in image noise in the section of the body adjacent to the shield and further reduce the quantitative precision of CT numbers. In addition, shielding can degrade the overall efficiency (by an order of approximately 10%) of the imaging process, reducing the theoretical image quality that can be expected from a certain level of patient dose. However, in spite of their significant disadvantages, there are certain clinical situations and practice considerations that provide qualified justification for their continued use. PMID:25304710

  2. [Pros and cons of antipsychotics in children and adolescents].

    PubMed

    Schmeck, Klaus

    2015-08-01

    In the last decade the indication of antipsychotics has been expanded from the treatment of psychoses to the treatment of impulsive-aggressive behaviors in mentally retarded children and adolescents with conduct disorder or autism spectrum disorders. As a consequence the use of antipsychotics in children and adolescents has increased worldwide. This increase of prescriptions is under critical discussion. In this paper the indication and the potential side-effects of antipsychotics in children and adolescents are described. The risks of antipsychotic medication are contrasted with the potential benefits to arrive at rational treatment recommendations. PMID:26242421

  3. Pharmacological interventions for short stature: pros and cons.

    PubMed

    Rosenfeld, Ron G

    2013-01-01

    Although growth hormone (GH) therapy is virtually always effective in accelerating growth and restoring height potential to children with GH deficiency (GHD), the expansion of its use to a wide variety of other clinical disorders associated with short stature has resulted in considerable ethical and cost-benefit issues. Logic would demand that therapy should either be restricted to true 'replacement', thereby limiting its use to cases of unequivocal GHD, or treatment should be considered as a legitimate 'enhancement', and be available to all children with significant short stature. Consideration of the latter option requires a careful look at issues surrounding efficacy (both in terms of stature and any perceived disability resulting therefrom), cost and potential adverse effects. Similar concerns involve treatment with insulin-like growth factor-I and any related growth-augmenting therapy. To date, safety issues have been addressed through pharmaceutical-sponsored postmarketing surveillance studies. While of definite use, such investigations also have significant limitations, especially in addressing long-term concerns. The possibility of lifespan cohort studies, with surveillance of all GH recipients throughout life and comparison with data from appropriate controls, should be considered. PMID:23502156

  4. Bilateral adrenalectomy for Cushing's syndrome: Pros and cons

    PubMed Central

    Prajapati, O. P.; Verma, A. K.; Mishra, A.; Agarwal, G.; Agarwal, A.; Mishra, S. K.

    2015-01-01

    Aim: To assess the outcome of patients undergoing bilateral adrenalectomy for Cushing's syndrome (CS). Methods: All patients who underwent bilateral adrenalectomy for CS at the Department of Endocrine Surgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences hospital between 1991 and 2013 were included. Medical records were reviewed to obtain patient characteristics and follow-up data. Results: Twenty-seven patients were studied. Mean age was 28.74 ± 12.95 years (range 9–60), male:female ratio was 1.7:1. About half that is, 48.19% were of Cushing's disease (failed trans-sphenoidal surgery [TSS]), 37.04% were of ectopic CS (ECS), and 14.81% were of CS due to bilateral adrenal pathology. Median follow-up period was 80.5 months. Before surgery, 74.1% patients had body mass index > which after surgery declined to <25 in 75% of them. Hypertension was present in 85.2% and after surgery resolved in 40%. Diabetes mellitus was present in 44.4% and after surgery resolved in 33% of them. Hirsutism and proximal muscle weakness were present in 55.6% and 70.4% patients, respectively, and after surgery improved markedly in all patients. Adrenal crisis developed in 36.3% and Nelson's syndrome in 41.7% patients during follow-up. Three patients died in perioperative period while three succumbed to the disease during follow-up. Two patients developed recurrence of endogenous cortisol production during the follow-up period. Conclusions: Bilateral adrenalectomy is a valid treatment option for palliating severe symptoms in Pituitary Cushing's with failed TSS and unlocalized ECS but the procedure is curative for CS due to bilateral adrenal disease. Overall morbidity and mortality is higher than other endocrine operations. Co-morbidities tend to be more severe and are a risk factor for mortality during the time patient survives. PMID:26693437

  5. 9 CFR 319.301 - Chili con carne with beans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (Species) may be used in accordance with § 319.6. Head meat, cheek meat, or heart meat exclusive of the heart cap may be used to the extent of 25 percent of the meat ingredients, and its presence shall...

  6. 9 CFR 319.301 - Chili con carne with beans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (Species) may be used in accordance with § 319.6. Head meat, cheek meat, or heart meat exclusive of the heart cap may be used to the extent of 25 percent of the meat ingredients, and its presence shall...

  7. 9 CFR 319.301 - Chili con carne with beans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (Species) may be used in accordance with § 319.6. Head meat, cheek meat, or heart meat exclusive of the heart cap may be used to the extent of 25 percent of the meat ingredients, and its presence shall...

  8. 9 CFR 319.301 - Chili con carne with beans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (Species) may be used in accordance with § 319.6. Head meat, cheek meat, or heart meat exclusive of the heart cap may be used to the extent of 25 percent of the meat ingredients, and its presence shall...

  9. The pros and cons of using irradiation for phytosanitary treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is increasingly being used as a phytosanitary treatment in Asia, Australia and the Americas, but the process is not being used or promoted in the European Union. However, under the current regulatory framework it is possible for food commodities irradiated to prevent the spread of alien ...

  10. Choice-Based Credit System in India: Pros and Cons

    ERIC Educational Resources Information Center

    Hasan, Mohammad; Parvez, Mohammad

    2015-01-01

    Education system of India is full of intricacies of different nature. Every ladder of education has its own problems and prospects. However, attempts have been taken to lessen complexities. From ages, time to time commissions have been constituted to improve and remove the anomalies of Indian education system especially, ensuring quality and…

  11. Pros and cons of power combined cycle in Venezuela

    SciTech Connect

    Alvarez, C.; Hernandez, S.

    1997-09-01

    In Venezuela combined cycle power has not been economically attractive to electric utility companies, mainly due to the very low price of natural gas. Savings in cost of natural gas due to a higher efficiency, characteristic of this type of cycle, does not compensate additional investments required to close the simple cycle (heat recovery steam generator (HRSG) and steam turbine island). Low gas prices have contributed to create a situation characterized by investors` reluctance to commit capital in gas pipe lines and associated equipment. The Government is taking measures to improve economics. Recently (January 1, 1997), the Ministry of Energy and Mines raised the price of natural gas, and established a formula to tie its price to the exchange rate variation (dollar/bolivar) in an intent to stimulate investments in this sector. This is considered a good beginning after a price freeze for about three years. Another measure that has been announced is the implementation of a corporate policy of outsourcing to build new gas facilities such as pipe lines and measuring and regulation stations. Under these new circumstances, it seems that combined cycle will play an important role in the power sector. In fact, some power generation projects are considering building new plants using this technology. An economical comparative study is presented between simple and combined cycles power plant. Screening curves are showed with a gas price forecast based on the government decree recently issued, as a function of plant capacity factor.

  12. Biomarkers for diagnosis in thoracic aortic disease: CON.

    PubMed

    Farkas, Emily A

    2010-05-01

    The fundamental requirements for a meaningful biomarker have not been met in the prediction of the aneurysm trait, the progression of the aneurysm disease state, or the prevention of catastrophic aortic complications. Aortic aneurysm is a worthy opponent on all fronts, and clinicians should continue actively to evaluate all potential diagnostic and therapeutic adjuncts with high levels of scientific scrutiny and rigor, so that the understanding and management of this disease process evolves in a complementary, rather than duplicative, manner. In the meantime, proteomics, genomics, and metabolomics continue to represent a muse of sorts in scientific circles, but clinicians are responsible for verifying the relevance and meaningful application of its postulates as they apply to individual patients within the context of efficient and effective global health care delivery. PMID:20452530

  13. Umbilical cord blood transplantation: pros, cons and beyond.

    PubMed

    Stanevsky, Anfisa; Goldstein, Gal; Nagler, Arnon

    2009-09-01

    Large body of clinical and scientific data has been generated since the first cord blood transplantation (CBT) was performed in 1989. Superior immune plasticity of CB grafts, that allows for less stringent HLA matching, is especially valuable in the face of a persistently growing need for unrelated donor (UD) transplants. Limited cell dose remains the main setback of CBT, particularly in adult population. New strategies, such as transplantation with two cord blood units or using non-myeloablative conditioning, have remarkably expanded the availability of CB transplants in adults with hematological malignancies. Clinical trials with in vitro expanded CB-derived stem cells are under way. Currently cord blood is considered a second best choice after matched bone marrow. However, results of recent international studies indicate that in particular clinical settings, such as in children with leukemia, CB may become a frontline hematopoietic stem cell (HSC) source for transplantation. Recent advances in understanding the unique biology of cord blood will further expand indications for its use in different settings, including those beyond hematopoietic stem cells transplantation (HSCT). PMID:19282073

  14. Ovarian Stem Cells-the Pros and Cons.

    PubMed

    Evron, Ayelet; Blumenfeld, Zeev

    2013-03-20

    The potential for postnatal de novo oogenesis in mammals and in humans has become very controversial in the fields of reproductive science and biology. Historically, it has been thought that females of most mammalian species lose the ability to produce oocytes at birth. A contemporary understanding of stem cell biology together with novel experimental methods has challenged the model of a prenatal fixed ovarian primordial follicle pool that declines with age. Researchers have suggested replenishment of post-natal oocytes by germ-line stem cells (GSCs). According to this theory, GSCs produce oocytes and primordial follicles throughout the lifetime of the adult female. This review describes recent approaches supporting the revolutionary idea of de novo oogenesis in mammals and humans of reproductive-age and provides counter arguments from opponents of this novel and innovative concept. PMID:24453518

  15. Vegetarian, vegan or meat eater. The pros and the cons.

    PubMed

    Ball, M

    1997-11-01

    This article discusses the potential health benefits of a vegetarian diet, while highlighting some potential problems that may occur if such a dietary regimen is adopted, particularly in certain groups. It emphasises the importance of health professionals contributing to people's knowledge of nutrition in order to allow them to choose a healthy diet, whether they are vegetarian or meat eaters. PMID:9386308

  16. Pros and Cons of Paper and Electronic Surveys

    ERIC Educational Resources Information Center

    Porter, Stephen R.

    2004-01-01

    This chapter describes the different types of paper and electronic surveys currently available and their costs and benefits in terms of equipment and printing costs, demands on staff time, and ease of use.

  17. Pros and cons of the nonsurgical treatments for gallbladder stones.

    PubMed

    Thistle, J L

    1989-10-01

    Dissolution of gallbladder stones is usually possible if the cholesterol content of the stones is high. Oral treatment with chenodiol or ursodiol is least invasive, but also least effective and slow. methyl tert-butyl ether requires delivery by percutaneous transhepatic catheter, but is rapidly effective. Extracorporeal shock wave lithotripsy enhances dissolution by oral bile acids, but is highly effective only for solitary stones less than or equal to 20 mm in diameter. Percutaneous cholecystostomy is most invasive, but effective regardless of stone composition. Stones will probably recur in 50 percent of patients with a patent cystic duct and intact gallbladder. PMID:2695446

  18. Two Year College Faculty Problems: Master Contracts, Pros and Cons.

    ERIC Educational Resources Information Center

    Morgan, Don A., Ed.

    The principal papers presented at this conference were as follows: (1) "We've Come a Long Way, Baby" by Thomas F. Stark, (2) "Hey! Who Runs This Show?" by Clair T. Blikre, and (3) "Bargaining Allows Teachers to Teach!" by Ralph Chesebrough. The background, purposes and activities of the Iron Range Institute are described. The appendix, Career…

  19. Pros and cons for C4d as a biomarker

    PubMed Central

    Cohen, Danielle; Colvin, Robert B.; Daha, Mohamed R.; Drachenberg, Cinthia B.; Haas, Mark; Nickeleit, Volker; Salmon, Jane E.; Sis, Banu; Zhao, Ming-Hui; Bruijn, Jan A.; Bajema, Ingeborg M.

    2013-01-01

    The introduction of C4d in daily clinical practice in the late nineties aroused an ever-increasing interest in the role of antibody-mediated mechanisms in allograft rejection. As a marker of classical complement activation, C4d made it possible to visualize the direct link between anti-donor antibodies and tissue injury at sites of antibody binding in a graft. With the expanding use of C4d worldwide several limitations of C4d were identified. For instance, in ABO-incompatible transplantations C4d is present in the majority of grafts but this seems to point at ‘graft accommodation’ rather than antibody-mediated rejection. C4d is now increasingly recognized as a potential biomarker in other fields where antibodies can cause tissue damage, such as systemic autoimmune diseases and pregnancy. In all these fields, C4d holds promise to detect patients at risk for the consequences of antibody-mediated disease. Moreover, the emergence of new therapeutics that block complement activation makes C4d a marker with potential to identify patients who may possibly benefit from these drugs. This review provides an overview of the past, present, and future perspectives of C4d as a biomarker, focusing on its use in solid organ transplantation and discussing its possible new roles in autoimmunity and pregnancy. PMID:22297669

  20. Entrenamiento con el traje espacial - Duration: 2 minutes, 21 seconds.

    NASA Video Gallery

    Después de 10 paseos espaciales, el astronauta de la NASA Michael López- Alegría sabe bastante de trajes espaciales. En este video, López Alegría comparte su experiencia acerca del uso y el entrena...

  1. Learners or Participants? The Pros and Cons of "Lifelong Learning"

    ERIC Educational Resources Information Center

    Mantie, Roger

    2012-01-01

    Whereas adult education used to be the preferred concept for those studying adult music-making, there is now an increasing trend away from this and towards lifelong learning. Uncritically adopting government lifelong learning discourses, however, blurs the line between educational ideals and political ones. Although there may be merit in the…

  2. The pros and cons of using irradiation for phytosanitary treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is increasingly being used as a phytosanitary treatment in Asia, Australia and the Americas, but the process is not being used or promoted in the European Union. However, under the current regulatory framework it is possible for food commodities irradiated to prevent the spread of alien...

  3. Does chemotherapy prevent HCV-related hepatocellular carcinoma? Cons.

    PubMed

    Craxì, Antonio; Cammà, Calogero

    2010-07-01

    The accuracy and the reliability of well-recognized clinical, virologic, histologic, and molecular risk factors for hepatocellular carcinoma (HCC) are still insufficient. Thus, accurate risk prediction of cancer development in individual patients with the aim of selecting high risk cohorts of patients for HCC chemoprevention programs remains an elusive goal. Future directions in chemoprevention of HCC will be in the development of molecular risk models and of new chemopreventive agents. Studies examining multiple genes and proteins (genomics and proteomics) in the same HCCs will be required to evaluate this possibility thoroughly. A strategy aiming at preventing chronic liver disease of any etiology (HCV and HBV infection, alcohol, obesity, others) may be required to prevent HCC in low and intermediate incidence areas, and hence, worldwide. In the setting of secondary chemoprevention, literature data pooling suggests a slight preventive effect of interferon (IFN) on HCC development in patients with HCV-related cirrhosis. The magnitude of this effect is low, and the observed benefit might be due to spurious associations. The preventive effect is limited to sustained virological responders to IFN. So, there is no sound evidence to support a recommendation for widespread use of IFN to prevent HCC in HCV-related cirrhosis. In the setting of tertiary chemoprevention, the risk of recurrence of HCC may be reduced by IFN treatment in selected patient populations. Further large-scale multicenter randomized controlled trials may prove useful to evaluate the benefit on overall survival. PMID:20547316

  4. Pros and Cons of TQM for Student Affairs.

    ERIC Educational Resources Information Center

    Howard, Nancy Lee

    1996-01-01

    Explores the key benefits and costs of implementing Total Quality Management (TQM) in student affairs. Discusses the experiences of early innovators and uses specific criteria to analyze TQM. Outlines effects on financial aid, costs, goal achievement, time and resource commitment, long-term focus, leaders as models, and clarity of mission. (RJM)

  5. Stories in Games for Health: More Pros or Cons?

    PubMed

    Baranowski, Moderator Tom; Lu, Participants Amy Shirong; Buday, Richard; Lyons, Elizabeth J; Schell, Jesse; Russoniello, Carmen

    2013-10-01

    There has been a debate about whether entertainment videogames should incorporate story or narrative. A concern has been whether story cut scenes break game immersion, and thereby minimize the fun of gameplay. Alternatively, games for health (G4H) have an agenda that goes beyond just having fun. The possible role of story in G4H has not been thoroughly addressed. We have assembled a group of experts who have worked with stories in G4H, and asked some pointed questions. PMID:26196925

  6. WIND WATER PUMPING / BOMBE DE AGUA CON ENERGIA EOLICA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind power has been used to pump water for centuries; however, the development of the modern wind turbine has allowed for more applications for water pumping. This book, now available in Spanish, was written to give a complete overview of wind power water pumping and serves as a design guide for wa...

  7. Dying in dignity: the pros and cons of assisted suicide.

    PubMed

    Diekstra, R F

    1995-05-01

    This paper describes the historical background and the current situation regarding the practice of assisted suicide in The Netherlands. It outlines and discusses what is considered to be the 'golden standard' of conduct for doctors and other health professionals in this area, it describes experiences with the application of this standard and discusses some of the major pitfalls involved. It also describes the results of several empirical studies on the attitudes of the general public, and the nature and magnitude of the practice of assisted suicide in the country. It is concluded that although perfect application of the 'Dutch Protocol' encourages and supports careful and responsible professional conduct regarding assisted suicide and provides satisfactory safeguards both for the patients involved, (potential) survivors and society as a whole, there are many cases where the desired perfection is far from feasible, hence assistance with suicide remains very hazardous. It is also concluded, however, that health care policy makers, as well as professionals, should confront the issue of assisted suicide, since, as the historical development in The Netherlands has shown, repression and denial implicates the worst of all possible scenarios, and does not contribute at all to the primordial goals of a humane health care system: the alleviation of suffering and the prevention of premature death. PMID:9179959

  8. Grupos de galaxias con corrimiento al rojo intermedio

    NASA Astrophysics Data System (ADS)

    Salerno, J. M.; Muriel, H.; Alonso, M. V.; Valotto, C.

    2015-08-01

    We present the construction of a catalog of groups of galaxies obtained through a sample of 677 spectra obtained with VIMOS-MOS spectrograph at the VLT. The sample has a redshift range and includes randomly selected galaxies brighter than in the R band. Groups of galaxies are identified using the algorithm Friends-of-friends (FOF). Linking lengths are taken as and . We also performed a visual reconstruction of the FOF groups. Finally, the basic properties of groups were estimated: velocity dispersion, virial mass and radius.

  9. Clinical drawbacks of total lymphoid irradiation: the cons

    SciTech Connect

    Myers, L.W.; Ellison, G.W.; Fahey, J.L.; Tesler, A.; Gottlieb, M.S.

    1988-07-01

    Success has been reported with use of total lymphoid irradiation (TLI) in organ transplant recipients and in patients with rheumatoid arthritis and other autoimmune diseases. In a well-conducted randomized double blind clinical trial, Cook et al have found that TLI was superior to sham irradiation of patients with multiple sclerosis (MS). However, it is clear from looking at this data that not all patients responded to TLI and that with time disease activity returned. Our own experience with TLI in two MS patients was very disappointing. Despite its apparent benefit in some conditions, considerable drawbacks are associated with TLI. These include high financial cost, unpleasant treatment-related side effects, and the possibility that more serious morbidity as well as mortality may be treatment-related. Furthermore, the optimum therapeutic regimen for TLI has not yet been established. Issues related to cumulative dose, dose per fraction, frequency of fractions, field of irradiation, and interaction with other therapies still need clarification. For these reasons we do not recommend TLI as a treatment for MS.

  10. Re(con)ceiving Young Children's Curricular Performativity

    ERIC Educational Resources Information Center

    Sellers, Marg

    2010-01-01

    Working (with) Deleuzo-Guattarian philosophical imaginaries opens (to) a multiplicity of possibilities for thinking differently about curriculum, young children and how they perform their curricular understandings. In this article I work (as) rhizome, bringing the imaginaries "becoming" and "milieu" into an early childhood curriculum conversation…

  11. Monitoreo de blazares con el Telescopio Whipple de rayos gamma

    NASA Astrophysics Data System (ADS)

    Pichel, A.; Rovero, A. C.

    Since September 2005, the Whipple 10 m Gamma-ray Telescope has been used primarily to monitor known TeV blazars. The five blazars that have been previously detected at Whipple: Markarian 421, H1426+428, Markarian 501, 1ES 1959+650 and 1ES 2344+514, are monitored each night that they are visible. Alerts are sent to VERITAS any time these objects are flaring to trigger ToO observations. The light curves for these blazars are produced and combined with observations in radio, optical and X-ray in the frame of Multiwavelengths Campaigns. We present here the results for the 2005-08 observations on Mrk421. FULL TEXT IN SPANISH

  12. Encompassing Sexual Medicine within Psychiatry: Pros and Cons

    ERIC Educational Resources Information Center

    Segraves, Robert Taylor

    2010-01-01

    Objective: This article examines the positive and negative aspects of psychiatry encompassing sexual medicine within its purview. Methods: MEDLINE searches for the period between 1980 to the present were performed with the terms "psychiatry," "sexual medicine," and "sexual dysfunction." In addition, sexual medicine texts were reviewed for chapters…

  13. A (Con)text for New Discourse as Semiotic Praxis

    ERIC Educational Resources Information Center

    Fulkova, Marie; Tipton, Teresa M.

    2008-01-01

    Contemporary art requires that art and cultural educators reposition encounters with artefacts, images and performances into a context for new discourses. Whereas digital media and other aspects of visual popular culture predominate the frames of reference of school-age children, their context (codes) of reference, in large part, do not contain…

  14. [Infertility over forty: Pros and cons of IVF].

    PubMed

    Belaisch-Allart, J; Maget, V; Mayenga, J-M; Grefenstette, I; Chouraqui, A; Belaid, Y; Kulski, O

    2015-09-01

    The population attempting pregnancy and having babies is ageing. The declining fertility potential and the late age of motherhood are increasing significantly the number of patients over forty consulting infertility specialists. Assisted reproductive technologies (ART) cannot compensate the natural decline in fertility with age. In France, in public hospital, ART is free of charge for women until 43 years, over 43, social insurance does not reimburse ART. Hence, 43 years is the usual limit, but between 40 and 42 is ART useful? The answer varies according to physicians, couples or society. On medical level, the etiology of the infertility must be taken into account. If there is an explanation to infertility (male or tubal infertility) ART is better than abstention. If the infertility is only due to age the question is raised. In France, the reimbursement by the society of a technique with very low results is discussed. However efficacy is not absolutely compulsory in Medicine. On the opposite to give false hopes may be discussed too. To obtain a reasonable consensus is rather difficult. PMID:26297163

  15. Conciencia Con Compromiso: Aspirantes as Bridges for Latin@ Bilingual Learners

    ERIC Educational Resources Information Center

    Prieto, Linda

    2014-01-01

    The study examined the influence of culture on the desire of a group of six aspirantes (Spanish/English bilingual education teacher candidates) from Texas to become bilingual education teachers of Latin@ bilingual learners. Chicana/Latina feminist thought is utilized as a lens to understand the role teacher education programs can play in helping…

  16. Pros and Cons of ID vs. 3D Modeling

    NASA Technical Reports Server (NTRS)

    Klimchuk, James A.

    2012-01-01

    Advances in computing capability have led to tremendous improvements in 3D modeling. Entire active regions are being simulated in what might be described as a first principles way, in which plasma heating is treated self consistently rather than through the specification of heating functions. There are limitations to this approach, however, as actual heating mechanisms on the Sun involve spatial scales orders of magnitude smaller than what these simulations can resolve. Other simulations begin to resolve these scales, but they only treat a tiny volume and do not include the all important coupling with larger scales or with other parts of the atmosphere, and so cannot be readily compared with observations. Finally, ID hydrodynamic models capture the field-aligned evolution of the plasma extremely well and are ideally suited for data comparison, but they treat the heating in a totally ad hoc manner. All of these approaches have important contributions to make, but we must be aware of their limitations. I will highlight some of the strengths. and weaknesses of each.

  17. Astronomia solare e ottica con il foro stenopeico

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino

    The observation of the Sun with pinholes was started in Florence's Cathedral in 1475, and in Ulugh Beg observatory in Samarcand in 1424-29, well before the invention of the telescope, for measuring the solar position and the variation of the obliquity of the Earth's axis. Later, with Kepler, pinholes' telescopes were used to follow the solar spots when the telescopes made by Galileo were not available. The use of pinholes in positional solar astrometry continued successfully up to 1800 in some great Italian and French Churches. Nowadays by using pinholes it is possible to show the principles of positional astronomy and imaging to students with instruments very easy to be built at almost no cost. The concepts of focal length, best focus, angular resolution, atmospheric seeing and atmospheric transmittance can be verified with such simple devices. Such pinhole telescopes have been built by primary-school students at the Astronomical Observatory dedicated to the Pope astronomer Sylvester II, located in Bukowiec, Poland, which is at its third year of activity. The largest solar spots have been observed clearly with these instruments, demonstrating the principles discussed in this presentation. The light cast by one of this devices with 70 m of focal length and 1 cm of diameter has permitted to repeat the experiences on the diffraction of the light, made in 1648 by the Jesuits Riccioli and Grimaldi.

  18. FILM E COPERTURE EDULI CON MATRICI A BASE DI FRUTTA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Films based on pear puree were formed using thermal compression molding. Whey protein isolates and soy protein isolates were added to these films to improve their processing and strength. The effects of pear puree concentration, whey or soy protein concentration, moisture content and sorbitol cont...

  19. Neutron Assay System for Con?nement Vessel Disposition

    SciTech Connect

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

    2012-07-13

    Waste will be removed from confinement vessels remaining from 1970s-era experiments. Los Alamos has 9+ spherical confinement vessels remaining from experiments. Each vessel contains {approx} 500 lbs of radioactive debris such as actinide metals and oxides, metals, powdered silica, graphite, and wires and hardware. In order to dispose of the vessels, debris and contamination must be removed. Neutron assay system was designed to assay vessels before and after cleanout. System requirements are: (1) Modular and moveable; (2) Capable of detecting {approx}100g {sup 239}Pu equivalent in a 2-inch thick steel sphere with 6 foot diameter; and (3) Capable of safeguards-quality assays. Initial design parameters arethe use of 4-atm {sup 3}He tubes with length of 6 feet, and {sup 3}He tubes embedded in polyethelene for moderation. This paper describes the calibration of the Confinement Vessel Assay System (CVAS) and quantification of its uncertainties. Assay uncertainty depends on five factors: (1) Statistical uncertainty in the assay measurement; (2) Statistical uncertainty in the background measurement; (3) Statistical uncertainty in the isotopics determination - This should be much smaller than the other uncertainties; (4) Systematic uncertainty due to position bias; and (5) Systematic uncertainty due to fluctuations in cosmic ray spallation. This one can be virtually eliminated by performing the background measurement with an empty vessel - but that may not be possible. We used modeling and experiments to quantify the systematic uncertainties. The calibration assumes a uniform distribution of material, but reality will be different. MCNPX modeling was used to quantify the positional bias. The model was benchmarked to build confidence in its results. Material at top of vessel is 44% greater than amount assayed, according to singles. Material near 19-tube detector is 38% less than amount assayed, according to singles. Cosmic ray spallation contributes significantly to the background. Comparing rates with and without a vessel showed that spallation adds an average of 27.27 singles/s and 5.45 doubles/s to background. Errors in the background rates were estimated at 20%.

  20. Pros and cons of the ambulatory surgery center joint venture.

    PubMed

    Giannini, Deborah

    2008-01-01

    If a physician group has determined that it has a realistic patient base to establish an ambulatory surgery center, it may be beneficial to consider a partner to share the costs and risks of this new joint venture. Joint ventures can be a benefit or liability in the establishment of an ambulatory surgery center. This article discusses the advantages and disadvantages of a hospital physician-group joint venture. PMID:18061764