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1

The role of P2O5 in silicate melts  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

2

Synthesis of CaO-SiO2-P2O5 mesoporous bioactive glasses with high P2O5 content by evaporation induced self assembly process.  

PubMed

Mesoporous bioactive glasses (MBGs) of the CaO-SiO(2)-P(2)O(5) system containing relatively high P(2)O(5) contents (10-30 mol%) were prepared from a sol-gel. An evaporation-induced self-assembly (EISA) technique was used with poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (EO(20)-PO(70)-EO(20), P123) acting as a template. The structural, morphological and textural properties of MBGs were investigated by small-angle X-ray diffraction (SAXRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and a N(2) sorption/desorption technique. SAXRD and TEM results display the reduced long-range ordering of mesopores with increasing P(2)O(5) content. N(2) sorption/desorption analysis shows that all three samples exhibit a type IV isotherm with type H1 hysteresis loops, characteristic of independent cylindrical slim pore channels and this material has a Barret-Joyner-Halenda (BJH) model pore size of ~4 nm and BET specific surface area ~430 m(2)/g. NMR results indicate a more condensed framework for samples with 30 mol% P(2)O(5) than samples with 10 mol% P(2)O(5). For in vitro bioactivity tests where samples were soaked in simulated body fluid (SBF), samples with 30 mol% P(2)O(5) showed higher crystallinity than those with lower P(2)O(5) contents Silicon concentration increased in SBF solution during the soaking period, which indicates MBGs can be degradable in SBF solution. PMID:21170573

Zhao, Shan; Li, Yanbao; Li, Dongxu

2011-02-01

3

V2O5-P2O5 glasses as cathode for lithium secondary battery  

SciTech Connect

In connection with studies related to the design of rechargeable lithium cells, a large variety of materials has been discovered and evaluated for use as reversible cathodes and electrolytes. The present investigation is concerned with electrochemical data which have been obtained on rechargeable vanadate glasses in the system V2O5-P2O5. Attention is given to IR spectra of V2O5 crystal and V2O5-P2O5 glasses, the rate capability of 95 mole pct V2O5-P2O5 glass, the cycling behavior of 95 mole pct V2O5-P2O5 glass at 1 mA/sq cm, and the cycle life performance of 95 mole pct V2O5-P2O5 glass at 0.5 mA/sq cm, 2.0-3.5 V voltage limited cycling.

Sakurai, Y.; Yamaki, J.

1985-02-01

4

V2O5-P2O5 glasses as cathode for lithium secondary battery  

Microsoft Academic Search

In connection with studies related to the design of rechargeable lithium cells, a large variety of materials has been discovered and evaluated for use as reversible cathodes and electrolytes. The present investigation is concerned with electrochemical data which have been obtained on rechargeable vanadate glasses in the system V2O5-P2O5. Attention is given to IR spectra of V2O5 crystal and V2O5-P2O5

Y. Sakurai; J. Yamaki

1985-01-01

5

The significance of Cl/P2O5 ratios from lunar samples  

NASA Technical Reports Server (NTRS)

The Cl(r)/P2O5 ratios of lunar samples are reported to occur in three groups (Jovanovic and Reed, 1975; etc.). These data have been modeled as representative of three discrete volumes of differentiating magma and correlated with large convection cells and moon-wide heterogeneities. The assumptions inherent to their model are not valid. That the Cl(r)/P2O5 ratio of apatite or a rock is indicative of a magma system is unrealistic. A range of ratios can be generated during the fractionation of a magma. Apatite is not the major Cl- and P-bearing phase in most of the samples analyzed; rust, FeO(OH, Cl) and schreibersite, (FeNi)3P, occur in over 2/3 rds of the Apollo 16 rocks where they constitute 0.1-0.6 modal %, enough to account for most of the Cl(r) and P2O5 analyzed. Due to the complexities and presence of these minerals in soils and breccias, Cl(r)/P2O5 ratios have no real significance in non-igneous samples. However, basaltic rocks alone do not define any statistically significant Cl(r)P2O5 groupings.

Taylor, L. A.; Hunter, R. H.

1982-01-01

6

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

NASA Astrophysics Data System (ADS)

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.

Hudon, Pierre; Jung, In-Ho

2014-05-01

7

Low Temperature Sintering of P2O5-Added Cordierite Glass with Borosilicate Glass  

NASA Astrophysics Data System (ADS)

Borosilicate glass was adopted as a sintering aid to improve the sinterability of P2O5-added cordierite glass. The flux effect of borosilicate glass aids the coalescence of cordierite glass particles, which promotes the densification. Crystallization of cordierite glass is the major reaction during the sintering of cordierite glass with borosilicate glass. Besides the advantage of lower sintering temperature, the addition of borosilicate glass lowers the dielectric constant of sintered composites.

Fu, Shen-Li; Chen, Lih-Shan

1993-03-01

8

Low Temperature Sintering of P2O5-Added Cordierite Glass with Lead Borosilicate Glass  

NASA Astrophysics Data System (ADS)

Cordierite was prepared by the sintering of cordierite glass and lead borosilicate glass. With the addition of lead borosilicate glass, P2O5-added cordierite glass can be densified at lower sintering temperature. Owing to the flux effect of lead borosilicate glass, the coalescence of glass particles was aided by the viscous flow of the glass. Besides the advantage of lower temperature sintering, the addition of lead borosilicate glass enhances the formation of ?-cordierite crystalline phase.

Chen, Lih-Shan; Fu, Shen-Li

1992-08-01

9

Vapor-phase synthesis of mesoporous SiO2-P2O5 thin films.  

PubMed

Mesoporous SiO2-P2O5 films were synthesized from the vapor phase onto a silicon substrate. First, a precursor solution of cetyltrimethylammonium bromide (C16TAB), H3PO4, ethanol, and water was deposited on a silicon substrate by a spin-coating method. Then, the C16TAB-H3PO4 composite film was treated with tetraethoxysilane (TEOS) vapor at 90-180 degrees C for 2.5 h. The H3PO4-C16TAB composite formed a hexagonal structure on the silicon substrate before vapor treatment. The TEOS molecules penetrated into the film without a phase transition. The periodic mesostructure of the SiO2-P2O5 films was retained after calcination. The calcined films showed a high proton conductivity of about 0.55 S/cm at room temperature. The molar ratio of P/Si in the SiO2-P2O5 film was as high as 0.43, a level that was not attained by a premixing sol-gel method. The high phosphate group content and the ordered periodic mesostructure contributed to the high proton conductivity. PMID:17373837

Nishiyama, Norikazu; Kaihara, Junji; Nishiyama, Yuko; Egashira, Yasuyuki; Ueyama, Korekazu

2007-04-24

10

Hydrothermal synthesis, structure and antiferromagnetism of Mn[P 2O 5(OH) 2  

Microsoft Academic Search

A new manganese diphosphate Mn[P2O5(OH)2] (1) has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group C2\\/c with the lattice: a=7.1487(14)Å, b=7.9804(16)Å, c=9.4812(19)Å, ?=101.18(3)°, V=530.63(18)Å3, and Z=4. Mn2+ is coordinated in a typical octahedral environment and the phosphates are dimerized as P2O7 groups. Each MnO6 is surrounded by six PO4 and each

Tao Yang; Yan Zhang; Ming Xiong; Fuhui Liao; Jianhua Lin

2008-01-01

11

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

NASA Astrophysics Data System (ADS)

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 ?eff 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.

ARDELEAN, I.; ANDRONACHE, C.; P??CU??, P.

12

Theoretical study of P2O5 polymorphs at high pressure: hexacoordinated phosphorus.  

PubMed

Binary oxides of elements belonging to groups 13-15 are of special relevance from a fundamental point of view as well as because of their technological applications as a basis in zeotypes, glasses, or semiconductors. Aluminum oxide, Al2O3, crystallizes in the corundum structure, which is stable at low and high pressures, with the Al showing octahedral coordination. Silicon oxide, SiO2, crystallizes in phases with tetrahedral Si coordination at low pressures as alpha-quartz, but at high pressures, octahedral coordination is stable in the stishovite polymorph. The only known binary phosphorus(V) oxides have tetrahedral P coordination. We have studied the stability of different phases of P2O5 at high pressure, applying density functional theory methodology within the local density and generalized gradient approximations and a plane-wave basis set. Our results indicate that the most stable form of P2O5 at high pressure could be one with hexacoordinated phosphorus. All of the high-pressure phases of Al, Si, and P can be described as a different linking of the same rutile-type blocks. PMID:18459763

Salvadó, Miguel A; Pertierra, Pilar

2008-06-01

13

Structure and some physical properties of PbO-P 2O 5 glasses  

NASA Astrophysics Data System (ADS)

Glasses in the system xPbO·(100- x)P 2O 5( x=25-60 mol%) have been investigated using IR spectroscopy and by means of density and electrical-resistivity measurements. The infrared spectra revealed that for PbO<50 mol% PbO enters the structure as a network modifier forming non-bridging oxygen ions. For PbO>50 mol% PbO also plays the role of a network former. The greater rate of density increase for PbO>50 mol% is due to the formation of PbO 4 units. The conductivity of these glasses depends mainly on the mobility of Pb 2+ ions. The variation of the electrical conductivity parameters upon changing the composition have been correlated with the structural changes in the glass matrix.

El-Egili, K.; Doweidar, H.; Moustafa, Y. M.; Abbas, I.

2003-12-01

14

P2O5 assisted green synthesis of multicolor fluorescent water soluble carbon dots.  

PubMed

A low cost synthesis of multicolor fluorescent carbon dots (C-dots) from edible sugars is described here. Common sugars like dextrose, lactose or maltose in aqueous medium gets dehydrated using phosphorus pentoxide (P2O5). The reaction is facile and completed within few minutes to form insoluble carbon (C-dots) mostly having the graphitic (G-band, Raman) sp2 hybridized carbon atoms (C-atoms). This insoluble carbon on oxidative treatment with nitric acid produced disordered sp3 (D-band retaining G-band, Raman) hybridized C-atoms, originated from the graphitic pool with sp2 hybridized C-atoms. This high density assimilation of self passivated "surfacial defects" become emissive during electronic transitions. Surfacial defects due to high degree of electrophilic carboxylation create the water soluble version of multicolor fluorescent C-dots as "water soluble fluorescent carbon dots" (wsFCDs). wsFCDs being itself self-passivated imposes the tunable multicolor emission throughout the visible spectrum without having any external coating and surface passivation and could be used as multicolor fluorescent probe especially in the emerging field of optical bio-imaging. PMID:24745229

Babar, Dipak Gorakh; Sonkar, Sumit Kumar; Tripathi, Kumud Malika; Sarkar, Sabyasachi

2014-03-01

15

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

PubMed

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

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

2012-02-01

16

A Coupled Experimental Study and Thermodynamic Modeling of the SiO2-P2O5 System  

NASA Astrophysics Data System (ADS)

A coupled key phase diagram experimental study and thermodynamic modeling of the SiO2-P2O5 system was conducted. Equilibration and quenching experiments using sealed Pt crucibles were performed in the SiO2-rich region to resolve inconsistencies found in the literature data about the SiO2 liquidus. Based on new experimental data and all available and reliable phase diagram and thermodynamic data, the thermodynamic optimization of the SiO2-P2O5 system was carried out to obtain a set of thermodynamic equations for liquid and solid phases in the system. The liquidus slope of SiO2 indicates that P2O5 in the SiO2-rich liquid exists mainly in the form of P2O7 4- instead of PO4 3-. Thermodynamic properties of the liquid solution can be predicted from the Gibbs energy of the liquid phase.

Rahman, Miftaur; Hudon, Pierre; Jung, In-Ho

2013-08-01

17

Structural and proton conductivity study of P 2O 5-TiO 2SiO 2 glasses  

Microsoft Academic Search

Proton conducting membranes for hydrogen fuel cell applications are being developed using sol–gel-derived P2O5-TiO2-SiO2 glasses. The present work is devoted to the structural analysis of P2O5-TiO2-SiO2 glasses containing controlled pore sizes and the surface area of the glasses reaching a maximum 410m2\\/g, while the average pore diameter is about 2.4nm. They were characterized by nitrogen adsorption–desorption measurements, thermal measurement as

T. Uma; S. Izuhara; M. Nogami

2006-01-01

18

A new experimental technique for determinations of the activities of P 2 O 5 and Fe x O—the system CaO-P 2 O 5 Fe x O  

Microsoft Academic Search

An experimental technique was applied for simultaneous determinations of the activities of P2O5 and FexO in slags. With this technique, phosphorus-containing liquid copper was heated inside an iron crucible at temperatures below\\u000a 1600 K. When copper is melted, the iron crucible dissolves into liquid copper, to a small extent, to form ternary {Cu-Fe-P}\\u000a liquid alloy, while ?Cu-Fe-P? solid solutions are

Y. Kaida; M. Hasegawa; M. Iwase; Y. Kikuchi; K. Wakimoto

2005-01-01

19

Interaction Studies Between Crofer-22APU Alloy And P2O5 Containing Barium Calcium Alumino-borosilicate (BCABS) Sealant Glass-Ceramics  

NASA Astrophysics Data System (ADS)

We present the effect of P2O5 addition on barium calcium aluminum borosilicate BCABS glasses of composition (mol %) 35BaO-15CaO-5Al2O3-(37-x)SiO2-8B2O3-xP2O5 (0<=x<=5). The incorporation of P2O5 increased network polymerization and crystallization tendency. However, addition of P2O5 leads to the formation of Cr2O3 at the interface, saturating it in the ions of the metal. This improves glass-to-metal bonding.

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

2010-12-01

20

Synthesis and structural characterization of P 2O 5–CaO–Na 2O sol–gel materials  

Microsoft Academic Search

Ternary phosphate-based glasses in the system P2O5–CaO–Na2O were synthesized using the sol–gel approach. Glasses in this system have the potential for use as bioactive materials. A mixture of mono- and dialkyl phosphate PO(OH)3?x(OC2H5)x (x=1,2) and alkoxides of sodium and calcium in an ethylene glycol solution were used as precursors. One of the compositions has also been synthesized by sonocatalysis (application

Daniela Carta; Jonathan C. Knowles; Mark E. Smith; Robert J. Newport

2007-01-01

21

Growth kinetics of spherulitic apatite in some MgO-CaO-SiO2-P2O5 glasses  

Microsoft Academic Search

Crystallization of glasses with compositions (wt%) of 11.2 MgO, 33.3 SiO2, (55.5-x) CaO, and xP2O5 (x=18.3, 16.65, 15.825 and 15.0) resulted in a spherulitic apatite phase with different crystal morphologies. An ellipsoidal morphology was observed for x=18.3, 16.65 and 15.825, and an anomalous morphology was observed for x=15.0. A metastable phase, which was similar in some characteristics to apatite, was

Jiin Jyh Shyu; JENN-MING WU

1994-01-01

22

FT-IR, Raman and thermoluminescence investigation of P 2O 5-BaO-Li 2O glass system  

NASA Astrophysics Data System (ADS)

The 0.5P 2O 5· xBaO·(0.5- x) Li 2O glass system (0 ? x ? 0.5 mol%) is investigated by FT-IR, Raman and thermoluminescence as a possible dosimetic material. FT-IR and Raman spectra show structural network modifications with the composition variations of the studied glasses. The predominant absorption band from IR spectra is attributed to the symmetric stretching vibrations of P = O double bonds. Raman spectra of the studied glasses contain also typical phosphate glasses bands. Thus the band at ˜700 cm -1 is assigned to symmetric stretching vibrations of P-O-P groups and that from ˜1158 cm -1 is attributed to symmetric stretching motions of the non-bridging oxygen (NBO) atoms bonded to phosphorous atoms (PO 2) in phosphate tetrahedron. Finally FT-IR and Raman spectroscopies revealed a local network structure mainly based on Q 2 and Q 3 tetrahedrons connected by P-O-P linkages. Luminescence investigations show that by adding modifier oxides to phosphate glass dose dependent TL signals result upon irradiation. Thus P 2O 5-BaO-Li 2O glass system is a possible candidate material for dosimetry in the high dose range (>10 Gy).

Ivascu, C.; Timar Gabor, A.; Cozar, O.; Daraban, L.; Ardelean, I.

2011-05-01

23

Phytic acid derived bioactive CaO-P2O5-SiO2 gel-glasses.  

PubMed

The possibility of using phytic acid as a precursor to synthesize CaO-P(2)O(5)-SiO(2) glasses by sol-gel method has been explored and the pseudo ternary phase diagram has been established. It was shown that gel-glasses over a broader range of compositions could be prepared compared to other phosphorus precursors or melt-quenching method. Furthermore, phytic acid was found to assist calcium being incorporated into glass networks. In vitro tests in simulated body fluid (SBF) were performed on the above gel-glasses and it was found that they were bioactive over a much broader compositional range especially at high phosphate content, thus enabling one to design bioactive materials with various degradation rates by adjusting the phosphate content. PMID:22042461

Li, Ailing; Qiu, Dong

2011-12-01

24

Enrichment Mechanism of Phosphate in CaO-SiO2-FeO-Fe2O3-P2O5 Steelmaking Slags  

NASA Astrophysics Data System (ADS)

The phosphate-enrichment behavior has experimentally been investigated in CaO-SiO2-FeO-Fe2O3-P2O5 steelmaking slags. The reaction ability of structural units in the slags has been represented the mass action concentration Ni from the developed ion and molecule coexistence theory (IMCT)- Ni model based on the IMCT. The defined enrichment possibility N_{{{{c}}i{{ {-}c}}j}} and enrichment degree R_{{{{c}}i{{{-}c}}j}} of solid solutions containing P2O5 from the developed IMCT- Ni model have been verified from the experimental results. The effects of binary basicity, the mass percentage ratio {{ ( {{pct Fe}}t {{O)}}} {/ {{{ ( {{pct Fe}}t {{O)}}} { ( {{pct CaO)}}}}} . -0pt} { ( {{pct CaO)}}}} , and mass percentage of P2O5 in the initial slags on phosphate-enrichment behavior in the slags has also been discussed. The results show that the P2O5 component can easily be bonded by CaO to form tricalcium phosphate 3 CaO·P2O5, and the formed 3CaO·P2O5 can react with the produced dicalcium silicate 2CaO·SiO2 to generate solid-solution 2CaO·SiO2-3CaO·P2O5 under fixed cooling conditions. The maximum value of the defined enrichment degree R_{{{{C}}_{ 2} {{S{-}}} {{C}}_{ 3} {{P}}}} of solid-solution 2CaO·SiO2-3CaO·P2O5 is obtained as 0.844 under conditions of binary basicity as 2.5 and the mass percentage ratio {{ ( {{pct Fe}}t {{O)}}} {/ {{{ ( {{pct Fe}}t {{O)}}} { ( {{pct CaO)}}}}} . -0pt} { ( {{pct CaO)}}}} as 0.955 at fixed cooling conditions.

Li, Jin-yan; Zhang, Mei; Guo, Min; Yang, Xue-Min

2014-05-01

25

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

PubMed

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 ?'(?), ??(?), imaginary parts of the electrical modulus, M(*)(?) and the loss tan?, 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

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

2014-01-01

26

Phase equilibria in the oxide system Nd 2O 3-K 2O-P 2O 5  

NASA Astrophysics Data System (ADS)

A phase equilibria diagram of the partial system NdPO 4-K 3PO 4-KPO 3 has been developed as part of the research aimed at determining the phase equilibrium relationships in the oxide system Nd 2O 3-K 2O-P 2O 5. The investigations were conducted using thermoanalytical techniques, X-ray powder diffraction analysis and reflected-light microscopy. Three isopleths existing between: K 3Nd(PO 4) 2-K 4P 2O 7, NdPO 4-K 5P 3O 10 and NdPO 4-K 4P 2O 7 have been identified in the partial NdPO 4-K 3PO 4-KPO 3 system. Previously unknown potassium-neodymium phosphate "K 4Nd 2P 4O 15" has been discovered in the latter isopleth section. This phosphate exists in the solid phase up to a temperature of 890 °C at which it decomposes into the parent phosphates NdPO 4 and K 4P 2O 7. Four invariant points: two quasi-ternary eutectics, E 1 (1057 °C) and E 2 (580 °C) and two quasi-ternary peritectics, P 1 (1078 °C) and P 2 (610 °C), occur in the NdPO 4-K 3PO 4-KPO 3 region.

Szczygie?, Irena; Znamierowska, Teresa; Mizer, Dagmara

2010-07-01

27

Structural and thermal properties of La2O3sbnd Fe2O3sbnd P2O5 glasses  

NASA Astrophysics Data System (ADS)

The structural properties of xLa2O3sbnd (40 - x)Fe2O3sbnd 60P2O5(x = 0, 2, 4, 6, 8, 10 mol%) glasses have been investigated by Fourier transform infrared spectrum (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The FTIR spectra show that the replacement of up to 6 mol% Fe2O3 by La2O3 does not produce any fundamental change in the glass structure, which consists predominantly of pyrophosphate, Q1 units. XRD analysis has confirmed that the majority of samples are X-ray amorphous, and crystallization occurs when the sample containing 8 mol% La2O3, the crystalline phase is LaPO4. The XRD analysis indicates that the solubility of lanthanum oxide in these iron phosphate melts is less than 8 mol%. Glass transition temperature (Tg) and (Tr - Tg) increase as the lanthanum content of the glass is increased. This result suggests that the glass network is strengthening and the thermal stability is improved with the addition of La2O3.

Qian, Bin; Yang, Shiyuan; Liang, Xiaofeng; Lai, Yuanming; Gao, Long; Yin, Guangfu

2012-03-01

28

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

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

29

Soft hydrothermal synthesis and characterization of M +2O-Cr 2O 3-P 2O 5 fine crystalline materials  

NASA Astrophysics Data System (ADS)

A series of M +2O-Cr 2O 3-P 2O 5 (M +=Na, K) materials have been synthesized via hydrothermal route. The resultant materials were characterized by SEM, powder XRD, FTIR and magnetic susceptibility studies. The powder X-ray studies revealed that the Na 2O-Cr 2O 3-P 2O 5 material has crystallized in orthorhombic system with cell parameters a=20.76764, b=8.86712, c=8.53437 Å, v=1571 Å3 and K 2O-Cr 2O 3-P 2O 5 material has crystallized in monoclinic system with and cell parameters a=11.8194, b=6.1518, c=11.0347 Å, ?=94.846, v=799.47 Å3. Repetitive hydrothermal treatment yielded improved crystalline materials. Magnetically these are paramagnetic, however, the ?eff decreased as the size of the material increased.

Gopalakrishna, G. S.; Mahesh, M. J.; Ashamanjari, K. G.

2005-11-01

30

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

NASA Astrophysics Data System (ADS)

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.

Choi, Hyoung-Seuk; Choi, Duck-Kyun

2013-09-01

31

Properties of lead–halide glasses in the PbBr 2–PbCl 2–PbF 2–PbO–P 2O 5 system  

Microsoft Academic Search

A series of new glasses in the PbBr2–PbCl2–PbF2–PbO–P2O5 systems have been prepared and some properties studied. The composition dependence of density, glass transition temperature (Tg), thermal expansion coefficient, water durability and optical transmission is reported. A glass in the PbBr2–PbCl2–P2O5 ternary system has glass transition temperature as low as 146°C and density as high as 4.75g\\/cm3. When PbO and\\/or PbF2

Dongmei Zhu; Wancheng Zhou; Hongsheng Zhao

2001-01-01

32

FTIR and Raman spectra of the Na 2O–CuO–Bi 2O 3–P 2O 5 glasses  

Microsoft Academic Search

The structure and properties were investigated for (50?y)Na2O–yCuO–10Bi2O3–40P2O5 (0?y?25 mol%) glasses. Substitution of Bi2O3 for Na2O in the binary 60Na2O–40P2O5 glass decreases the molar volume (?Vm=2.97 cm3\\/mol) and increases further the glass transition temperature (?Tg=52 °C). FTIR and Raman spectra reveal the formation of P?O?Bi and P?O?Cu bonds in these glasses and indicate that Bi2O3 behaves as a network former

A Chahine; M Et-tabirou; J. L Pascal

2004-01-01

33

Structural and optical investigations on CdSe-doped SiO2-P2O5 sol-gel films  

NASA Astrophysics Data System (ADS)

SiO2-P2O5 films doped with CdSe were prepared and investigated for temperature sensor applications. The films were synthesized by the sol-gel method, the sol being spin coated on glass substrates. The sols were prepared from tetraethoxysilane and phosphoric acid as precursors for SiO2 and P2O5, respectively, together with ethanol and water as the reaction environment and the hydrolysis reagent, respectively. The films were deposited at three different rotation rates, for 5 days starting from the first day after the sol preparation and thermally treated at 200, 300, 350, 400 and 550 °C in order to investigate the changes of the optical and structural properties.

Iordanescu, C. R.; Vasiliu, I. C.; Elisa, M.; Feraru, I. D.

2013-11-01

34

Sol-Gel SiO2-CaO-P2O5 biofilm with surface engineered for medical application  

Microsoft Academic Search

Sol-gel film in the SiO2-CaO-P2O5 system was prepared from TEOS, TEP, alcohol and hydrated calcium nitrate in an acidic medium. The coatings were deposited on stainless steel using the dip-coating technique. After deposition, the composite was submitted to heat treatment, at different temperatures and exposure times, to investigate the influence of such parameters on the surface morphology of the composite.

Sonia Regina Federman; Vilma Conceição Costa; Daniela Cordeiro Leite Vasconcelos; Wander Luiz Vasconcelos

2007-01-01

35

Ethylene carbonate\\/propylene carbonate\\/2-methyl-tetrahydrofuran ternary mixed solvent electrolyte for rechargeable lithium\\/amorphous V 2O 5-P 2O 5 cells  

Microsoft Academic Search

We have been studying a cell system which consists of an amorphous (a-) V2O5-P2O5 (95:5 in molar ratio) cathode, a lithium (Li) metal anode and an organic electrolyte by fabricating an AA-size prototype cell. In a previous study, we reported the influence of the mixing ratio of ethylene carbonate (EC) and propylene carbonate (PC) solvents, in EC\\/PC binary mixed solvent

Shin-Ichi Tobishima; Katsuya Hayashi; Yasue Nemoto; Jun-Ichi Yamaki

1997-01-01

36

Microstructure and mechanical properties of dental 3Y-TZP ceramics by using CaO–P 2O 5 glass as additive  

Microsoft Academic Search

This study investigated the effects of glass frits on the sintering and mechanical properties of dental 3Y-TZP ceramics. The glass frits, which consisted of MgO, CaO, Al2O3, SiO2, and P2O5, were selected to lower the sintering temperature of zirconia via liquid phase sintering.The results of the experiment showed that these glass frit additives neither destroy the stability of the high

Wen-Fu Ho; Hsueh-Chuan Hsu; Yun-Fen Peng; Shih-Ching Wu

2011-01-01

37

The Effect of P2O5 on the Crystallization Behaviors of Ti-Bearing Blast Furnace Slags Using Single Hot Thermocouple Technique  

NASA Astrophysics Data System (ADS)

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.

Sun, Yongqi; Li, Jing; Wang, Xidong; Zhang, Zuotai

2014-04-01

38

Li2SO4-Li2O-P2O5 ionic glass dispersed with [Bmim] [PF6] ionic liquid: Electrical transport and thermal stability investigations  

NASA Astrophysics Data System (ADS)

A fast ionic composite is prepared by dispersion of Ionic liquid [Bmim][PF6] in Li2SO4-Li2O-P2O5 glass matrix by mixing and through grinding. Amorphous/glassy nature of the samples is confirmed by X-Ray diffraction (XRD). Surprisingly, the electrical conductivity of the samples is found to be increasing by ˜ 2 orders of magnitude and exhibits typical Arrhenius behavior with low activation energy. DC polarization and impedance spectroscopy measurements suggest that samples are essentially ionic in nature. The conductivity isotherms were also obtained at different temperatures (T < 100 °C) and found to be appreciably stable at least for ˜ 10 days.

Rathore, Munesh; Dalvi, Anshuman; Kumar, Anil

2014-04-01

39

Effects of F, B 2 O 3 and P 2 O 5 on the solubility of water in haplogranite melts compared to natural silicate melts  

Microsoft Academic Search

The effects of F, B2O3 and P2O5 on the H2O solubility in a haplogranite liquid (36 wt. % SiO2, 39 wt. % NaAlSi3O8, 25 wt. % KAlSi3O8) have been determined at 0.5, 1, 2, and 3 kb and 800, 850, and 900°C. The H2O solubility increases with increasing F and B content of the melt. The H2O solubility increase in

François Holtz; Donald B. Dingwell; Harald Behrens

1993-01-01

40

Enhanced Raman gain coefficients and bandwidths in P2O5 and WO3 added tellurite glasses for Raman gain media  

NASA Astrophysics Data System (ADS)

The Raman gain coefficient and bandwidth of tellurite glasses have been tailored by systematically adding WO3 and P2O5 in a TeO2-BaO-SrO-Nb2O5 glass system. The Raman gain coefficients of the resultant glasses were obtained from spontaneous Raman scattering experiments using a 633 nm laser. The glasses developed here showed the widest gain bandwidths so far achieved in tellurite glasses while maintaining higher gain coefficients. The gain bandwidths of these glasses were more than twice that of a conventional tellurite-based glass and 70% larger than that of the silica glass.

Jose, Rajan; Ohishi, Yasutake

2006-09-01

41

Phosphorus Partition between Liquid Steel and CaO-SiO 2 -P 2 O 5 -MgO Slag Containing Low FeO  

Microsoft Academic Search

CaO-SiO2-FeO\\u000a x\\u000a -P2O5-MgO bearing slags are typical in the basic oxygen steelmaking (BOS) process. The partition ratio of phosphorus between slag\\u000a and steel is an index of the phosphorus holding capacity of the slag, which determines the phosphorus content achievable in\\u000a the finished steel. The influences of FeO concentration and basicity on the equilibrium phosphorus partition ratios were experimentally\\u000a determined

Somnath Basu; Ashok Kumar Lahiri; Seshadri Seetharaman

2007-01-01

42

The sol-gel prepared SiO2-CaO-P2O5 composites doped with Metronidazole for application in local delivery systems.  

PubMed

The aim of this study was to evaluate the physical properties, chemical structure and bioactivity of sol-gel processed oxide (SiO(2)-CaO-P(2)O(5)) composites used as controlled release materials for Metronidazole-drug applied in periodontal disease treatment. The obtained composite materials were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), the Brunauer-Emmet-Teller (BET) technique and further monitoring in the ultraviolet and visible light regions (UV-Vis) of the in vitro release of the drug over time. Using tetramethoxysilane (TMOS) as a precursor of silica matrix and calcium nitrate tetrahydrate (Ca(NO(3))(2) 4H(2)O), triethyl phosphite (P(OC(2)H(5))(3)) as precursors of CaO and P(2)O(5) respectively, xerogels with different morphology and physical properties were obtained. The applied modifications improved also the bioactivity and changed the profile of the drug release. Based on the presented results of this study, it may be concluded that applied xerogel matrices could be promising candidates for the formulation in local delivery systems. PMID:21480825

Czarnobaj, Katarzyna; Sawicki, Wies?aw

2012-01-01

43

Development and in vitro characterization of sol-gel derived CaO-P2O5-SiO2-ZnO bioglass.  

PubMed

A CaO-P(2)O(5)-SiO(2)-ZnO bioglass was formed by the sol-gel technique and characterized by Raman spectroscopy, X-ray diffraction, energy dispersive X-ray analysis (EDXA) and scanning electron microscopy (SEM). The surface reactivity of the resultant glass-ceramic specimens was analyzed by immersion studies in simulated body fluid (SBF). SEM-EDXS and inductively coupled plasma atomic emission spectrometry techniques were used to monitor changes in the glass surface and SBF composition. Osteoblast cell culture experiments were performed to assess the biocompatibility and the alkaline phosphatase activity. Cell counts of the osteoblasts cultured on the bioglass samples were studied and compared with the polystyrene plates. The cells cultured on the bioglass disks consistently showed a higher alkaline phosphatase activity and cell counts compared to cells cultured on either polystyrene plates or the base CaO-P(2)O(5)-SiO(2) bioglass. This was due to cell proliferation and differentiation promoted by the zinc-substituted bioglass. PMID:17134949

Balamurugan, Anbalagan; Balossier, Gerard; Kannan, Sanjeevi; Michel, Jean; Rebelo, Avito H S; Ferreira, Jose M F

2007-03-01

44

Fabrication of noble-metal nanoparticle-doped SiO2-B2O3-P2O5 waveguide films  

NASA Astrophysics Data System (ADS)

In this article, we report the fabrication and the characterization of Pt/SiO2-B2O3-P2O5 and Au/SiO2-B2O3-P2O5 composite thin films suitable for planar lightwave circuits (PLCs). The host material was prepared by using flame hydrolysis deposition (FHD). Platinum was doped from colloidal solutions with concentrations of 500, 1000, and 2000 ppm. Gold was doped by sputtering with various deposition times. The samples displayed absorption peaks originating from the surface plasmon resonance (SPR) of the dopant metal particles. With increasing dopant particle size, the absorption peak shifted toward longer wavelength, and the full width at half maximum (FWHM) of the absorption band broadened. The Maxwell-Garnett theory was used to explain the size dependence of the plasmon peaks. The dopant metal particles were found to order as a monolayer within the silica matrix, opening the possibility for surface-plasmon-resonance-based waveguiding in optical devices.

Lee, Hunhyeong; Kang, Minkyung; Nichols, William T.; Shin, Dongwook

2012-05-01

45

Sol-gel-derived bioactive glass containing SiO2-MgO-CaO-P2O5 as an antibacterial scaffold.  

PubMed

Bioactive glass (BG) composites with a base of SiO2-Na2O-CaO-P2O5 are biocompatible biomaterials. The assessment of their abilities for medical applications has interested researchers. We produced a BG-containing SiO2-MgO-CaO-P2O5 by the sol-gel method. To determine the antibacterial effects, we analyzed the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) properties of this product on three microorganisms, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, known causative agents for biofilm formation on implant surfaces. In addition, we performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to study the cytotoxic effects of our composite on animal cells. Our results demonstrated that our BG product inhibited the growth of bacteria in a concentration-dependent manner without any cytotoxic effects. Therefore, our BG product can be utilized as an appropriate implant for treating bone and tooth defects. PMID:23138930

Fooladi, Abbas Ali Imani; Hosseini, Hamideh Mahmoodzadeh; Hafezi, Forough; Hosseinnejad, Fatemeh; Nourani, Mohammad Reza

2013-06-01

46

Study of optical band gap and FTIR spectroscopy of Li2O.Bi2O3.P2O5 glasses.  

PubMed

Glasses having composition (25+x)Li(2)O.(65-x)P(2)O(5).10Bi(2)O(3) (0< or =x< or =25 mol%) were prepared by normal melt quenching technique. The optical absorption spectra of the polished samples were recorded in spectral range from 200 to 3300 nm at room temperature. The optical absorption edge (lambda(cutoff)), optical band gap (E(g)) and Urbach energy (DeltaE) were determined from the absorption spectra. Variation in these optical parameters has been associated with the structural changes occurring in these glasses with increase in Li(2)O:P(2)O(5) ratio. Variation in density (D), molar volume (V(M)) and glass transition temperature (T(g)) has also been correlated with structural changes in the glass samples. The FTIR spectra have been recorded in the spectral range from 400 to 1400 cm(-1). The FTIR spectra show the rapid depolymerization of phosphate chains with increase in Li(2)O content and P-O-Bi bonds are formed. PMID:19713150

Rani, S; Sanghi, S; Agarwal, A; Seth, V P

2009-10-15

47

Role of modifier oxide in emission spectra and kinetics of Er-Ho codoped Na 2SO 4-MO-P 2O 5 glasses  

NASA Astrophysics Data System (ADS)

The glasses of the composition 19Na 2SO 4-20MO-60P 2O 5: 1.0Ho 2O 3/1.0Er 2O 3 (M = Mg, Ca, and Ba) have been synthesized. Optical absorption and fluorescence spectra (in the spectral range 350-2100 nm were studied at ambient temperature. The spectra were characterized using Judd-Ofelt theory. From the luminescence spectra, various radiative properties like transition probability A, branching ratio ? and the radiative life time ? for blue (B), green (G) and red (R) emission levels of these glasses have been evaluated. The energy transfer between the two rare earth ions (Ho 3+ and Er 3+) in co-doped Na 2SO 4-MO-P 2O 5 glass systems in the visible and NIR regions has also been investigated. Highest intensity, the highest quantum efficiency and maximum energy transfer with low phonon losses of B, G, and R lines has been observed in BaO mixed glasses. The reasons for such higher values of these parameters have been discussed in the light of varying field strengths at the rare earths ion site due to replacement of one modifier oxide with the other. The enhanced intensity of NIR emission (at 2.0 ?m) has also been discussed in terms of cross relaxation of Er 3+ ions from 4I 13/2 level to 5I 7 of Ho 3+ ions.

Rao, P. Raghava; Venkatramaiah, N.; Gandhi, Y.; Kumar, V. Ravi; Kityk, I. V.; Veeraiah, N.

2012-02-01

48

Effect of magnesia on the degradability and bioactivity of sol-gel derived SiO2-CaO-MgO-P2O5 system glasses.  

PubMed

Mesoporous 58SiO(2)-(38-x)CaO-xMgO-4P(2)O(5) glasses (where x=0, 5, 10 and 20 mol%) have been prepared by the sol-gel synthesis route. The effects of the substitution of MgO for CaO on glass degradation and bioactivity were studied in tris-(hydroxymethyl)-aminomethane and hydrochloric acid buffer solution (Tris-HCl) and simulated body fluid (SBF), respectively. It is observed that the synthesized glasses with various MgO contents possess the similar textural properties. The studies of in vitro degradability and bioactivity show that the rate of glass degradation gradually decreases with the increase of MgO and the formation of apatite layer on glass surface is retarded. The influences of the composition upon glass properties are explained in terms of their internal structures. PMID:20667433

Ma, J; Chen, C Z; Wang, D G; Jiao, Y; Shi, J Z

2010-11-01

49

In vitro evaluation of bioactivity of CaO-SiO 2-P 2O 5-Na 2O-Fe 2O 3 glasses  

NASA Astrophysics Data System (ADS)

Glasses with compositions 41CaO(52 - x)SiO 24P 2O 5· xFe 2O 33Na 2O (2 ? x ? 10 mol.%) were prepared by melt quenching method. Bioactivity of the different glass compositions was studied in vitro by treating them with simulated body fluid (SBF). The glasses treated for various time periods in SBF were evaluated by examining apatite formation on their surface using grazing incidence X-ray diffraction, Fourier transform infrared reflection spectroscopy, scanning electron microscopy and energy dispersive spectroscopy techniques. Increase in bioactivity with increasing iron oxide content was observed. The results have been used to understand the evolution of the apatite surface layer as a function of immersion time in SBF and glass composition.

Singh, Rajendra Kumar; Kothiyal, G. P.; Srinivasan, A.

2009-05-01

50

Sol gel derived SiO(2)-CaO-MgO-P(2)O(5) bioglass system--preparation and in vitro characterization.  

PubMed

The synthesis of SiO(2)-CaO-MgO-P(2)O(5) bioactive glass was carried out by the sol-gel method. Sol-gel derived bioglass material was crushed into powder to produce pellet disks by uniaxial pressing, followed by sintering at 900 degrees C. The biocompatibility evaluation of the formed glass was assessed through in vitro cell culture experiments and immersion studies in simulated body fluid (SBF) for different time intervals while monitoring the pH changes and the concentration of calcium and magnesium in the SBF medium. Scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction analysis, and FT-IR spectroscopy studies were conducted before and after contact of the material with SBF. At first, an amorphous calcium phosphate was formed; after 21 days this surface consisted of deposited crystalline spheres of apatite. The present investigation also revealed that the sol-gel derived quaternary bioglass system has the ability to support the growth of osteoblast-like cells in vitro and to promote osteoblast differentiation by stimulating the expression of major phenotypic markers. PMID:17455268

Balamurugan, A; Balossier, G; Michel, J; Kannan, S; Benhayoune, H; Rebelo, A H S; Ferreira, J M F

2007-11-01

51

In vivo evaluation of CaO-SiO2-P2O5-B2O3 glass-ceramics coating on Steinman pins.  

PubMed

Surface coating using ceramics improves the bone bonding strength of an implant. We questioned whether a new type of glass-ceramics (BGS-7) coating (CaO-SiO2 -P2 O5 -B2 O3 ) would improve the osseointegration of Steinman pins (S-pins) both biomechanically and histomorphometrically. An in vivo study was performed using rabbits by inserting three S-pins into each iliac bone. The pins were 2.2-mm S-pins with a coating of 30-?m-thick BGS-7 and 550-nm-thick hydroxyapatite (HA), as opposed to an S-pin without coating. A tensile strength test and histomorphometrical evaluation was performed. In the 2-week group, the BGS-7 implant showed a significantly higher tensile strength than the S-pin. In the 4- and 8-week groups, the BGS-7 implants had significantly higher tensile strengths than the S-pins and HA implants. The histomorphometrical study revealed that the BGS-7 implant had a significantly higher contact ratio than the S-pin and HA implants in the 4-week group. The biomechanical and histomorphometrical tests showed that the BGS-7 coating had superior bone bonding properties than the groups without the coating from the initial stage of insertion. The BGS-7 coating of an S-pin will enhance the bone bonding strength, and there might also be an advantage in human bone bonding. PMID:23639194

Lee, Jae Hyup; Hong, Kug Sun; Baek, Hae-Ri; Seo, Jun-Hyuk; Lee, Kyung Mee; Ryu, Hyun-Seung; Lee, Hyun-Kyung

2013-07-01

52

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)

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 ??/?=0.2 and Ca/ ?III=1. The fields of crystallization of CsCaP 3O 9, ?-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, ?=37.2283(19) and 37.2405(17) Å, respectively.

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

2011-03-01

53

Pool-Frenkel effect and high frequency dielectric constant determination of semiconducting P2O5-Li2MoO4-Li2O and P2O5-Na2MoO4-Na2O bulk glasses  

NASA Astrophysics Data System (ADS)

The ternary 70P2O5-10Li2MoO4-20Li2O and 70P2O5-10Na2MoO4-20Na2O glasses, prepared by the press-melt quenching technique, were studied at temperatures between 298 and 418 K for their high dc electric field properties. For the above purpose, the effect of a strong electric field on the dc conduction of these amorphous bulk samples was investigated using the gap-type electrode configuration. At low electric fields, the current-voltage ( I — V) characteristics have a linear shape, while at high electric fields (> 103 V/cm), bulk samples show nonlinear effects (nonohmic conduction). Current-voltage curves show increasing departure from Ohm’s law with increasing current density, leading to critical phenomena at a maximum voltage (threshold voltage), known as switching (switch from a low-conduction state to a higher-conduction state at threshold voltage). The Pool-Frenkel high-field effect was observed at electrical fields of about 103 104 V/cm; then the lowering factor of the potential barrier, the high frequency dielectric constant, and the refractive index of these glasses were determined.

Souri, Dariush; Elahi, Mohammad; Yazdanpanah, Mohammad S.

2008-06-01

54

Molybdenum effect on the structure of SiO2 -CaO-P2 O5 bioactive xerogels and on their interface processes with simulated biofluids.  

PubMed

The study is focused on synthesis, investigation of the structural and morphological changes induced by MoO3 addition, and thermal treatment, as well as in vitro characterization of a new sol-gel derived SiO2 -CaO-P2 O5 bioactive materials. The obtained systems are composite materials consisting of nanocrystalline apatite, bioactive glass and CaMoO4 nanoparticles, which are of interest for both regenerative medicine and specific medical applications of the releasable molybdenum ions. The changes induced by the thermal treatments and MoO3 addition with respect to the structure and morphology were completed using differential thermal analysis\\thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, electron paramagnetic resonance, and Brunauer-Emmett-Teller. The biological performance of these materials was evaluated in vitro by performing bioactivity and biocompatibility tests. The bioactive properties in terms of hydroxyapatite layer formation on the biomaterial surface after simulated body fluid immersion were studied by XRD and SEM. To establish their biocompatibility, the biomaterials surface was functionalized with protein and the resulted sample was investigated using SEM, FTIR, and XPS. The obtained results suggest that the addition of molybdenum oxide in proper concentration improves the biocompatibility in terms of enhancement of protein adherence on Si-Ca-P surface due to CaMoO4 crystalline phase development and does not inhibit bioactivity. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3177-3185, 2014. PMID:24142573

Ponta, Oana; Ciceo-Lucacel, Raluca; Vulpoi, Adriana; Radu, Teodora; Simon, Simion

2014-09-01

55

Water adsorption and hydrolysis in the Si 2O 4, P 2O 5 and P 4O 10 systems - essential roles of the phosphate system in biosynthesis  

NASA Astrophysics Data System (ADS)

Successive water addition to the mononuclear species SiO 2(g) and PO 2(OH)(g), as well as the corresponding binuclear Si 2O 4(g) and P 2O 5(g) molecules, is studied by means of density functional theory. Hydrolysis of (HO) 3SiOSi(OH) 3(g) is found to be slightly endothermic, and only an asymmetric energy minimum is found for this silicic acid dimer. Four stable conformations are determined for the pyrophosphoric acid system (HO) 2OPOPO(OH) 2(g). Depending on the choice of reference structure and basis set, the hydrolysis energetics ranges from 14-26 kJ/mol exothermic to 3-7 kJ/mol endothermic. In general, the hydrolysis reaction is best described as a near zero-energy process. Significant differences in the water chemistry of the final monomeric products, Si(OH) 4(g) and PO(OH) 3(g), appear in the first solvation shell. Connecting the P-OH and P?O groups by water bridges results in a greater tendency for proton delocalization in PO(OH) 3(g), than is observed when water is used to connect two Si-OH groups in Si(OH) 4(g). Taking the properties of pyrophosphoric acid as model for the P-O-P bridge in adenosine triphosphate (ATP), the results of the present study support the notion that this molecule and its hydrolysis products provide a nano-scale buffer, which is essential for sustaining biosynthesis by controlling the proton and water activities.

Johnson, J. R. Tobias; Panas, Itai

2002-01-01

56

Evaluation of CaO-SiO2-P2O5-Na2O-Fe2O3 bioglass-ceramics for hyperthermia application.  

PubMed

Magnetic bioglass ceramics (MBC) are being considered for use as thermoseeds in hyperthermia treatment of cancer. While the bioactivity in MBCs is attributed to the formation of the bone minerals such as crystalline apatite, wollastonite, etc. in a physiological environment, the magnetic property arises from the magnetite [Fe3O4] present in these implant materials. A new set of bioglasses with compositions 41CaO x (52-x)SiO2 x 4P2O5 x xFe2O3 x 3Na2O (2 < or = x < or = 10 mol% Fe2O3) have been prepared by melt quenching method. The as-quenched glasses were then heat treated at 1050 degrees C for 3 h to obtain the glass-ceramics. The structure and microstructure of the samples were characterized using X-ray diffraction and microscopy techniques. X-ray diffraction data revealed the presence of magnetite in the heat treated samples with x > or = 2 mol% Fe2O3. Room temperature magnetic property of the heat treated samples was investigated using a Vibrating Sample Magnetometer. Field scans up to 20 kOe revealed that the glass ceramic samples had a high saturation magnetization and low coercivity. Room temperature hysteresis cycles were also recorded at 500 Oe to ascertain the magnetic properties at clinically amenable field strengths. The area under the magnetic hysteresis loop is a measure of the heat generated by the MBC. The coercivity of the samples is another important factor for hyperthermia applications. The area under the loop increases with an increase in Fe2O3 molar concentration and the. coercivity decreases with an increase in Fe2O3 molar concentration The evolution of magnetic properties in these MBCs as a function of Fe2O3 molar concentration is discussed and correlated with the amount of magnetite present in them. PMID:18560766

Singh, Rajendra Kumar; Srinivasan, A; Kothiyal, G P

2009-12-01

57

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

PubMed

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

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

2014-02-01

58

Preparation of 3-D scaffolds in the SiO2-P2O5 system with tailored hierarchical meso-macroporosity.  

PubMed

Herein we report for the first time the synthesis of three-dimensional scaffolds in the binary system SiO2-P2O5 exhibiting different scales of porosity: (i) highly ordered mesopores with diameters of ca. 4 nm; (ii) macropores with diameters in the 30-80 ?m range with interconnections of ca. 2-4 and 8-9 ?m; and (iii) ultra-large macropores of ca. 400 ?m. The hierarchical porosity of the resulting scaffolds makes them suitable for bone tissue engineering applications. The chemical nature and mesoporosity of these matrices would allow these scaffolds to act as local controlled delivery systems of biologically active molecules, such as certain drugs to treat bone pathologies. The synthetic method consists of the combination of a single-step sol-gel route in the presence of a surfactant as the mesostructure directing agent and a biomacromolecular polymer such as methylcellulose as the macrostructure template followed by rapid prototyping technique. An exhaustive study of the aging process as well as of the rheological properties of the slurry after methylcellulose addition has been carried out to obtain hierarchical meso-macroporosity. This study allows the establishment of the time period in which the slurry presents appropriate viscosity to be extruded during the rapid prototyping once the ink is prepared. The setting up of this manufacture process at the laboratory level is important from the industrial point of view when the large-scale production of scaffolds for bone tissue repair and regeneration is targeted. PMID:20951843

García, Ana; Izquierdo-Barba, Isabel; Colilla, Montserrat; de Laorden, Carlos López; Vallet-Regí, María

2011-03-01

59

Structural and thermal characterization of CaO-MgO-SiO2-P2O5-CaF2 glasses  

SciTech Connect

The paper presents the influence of varying CaO/MgO ratio on the structure and thermal properties of CaO-MgO-SiO2-P2O5-CaF2 glasses. A series of eight glass compositions in the glass forming region of diopside (CaMgSi2O6) - fluorapatite [Ca5(PO4)3F] - wollastonite (CaSiO3) ternary system have been designed and synthesized by varying diopside/wollastonite ratio in glasses. The as prepared melt-quenched glasses have been characterized for their structure by infrared spectroscopy (FTIR) and magic angle spinning (MAS)-nuclear magnetic resonance (NMR) spectroscopy. Silicon is predominantly present as Q2 (Si) species, while phosphorus tends to coordinate in orthophosphate environment in all the investigated glasses. The change in CaO/MgO ratio had an insignificant affect on the structure of glasses. The thermal sintering and crystallization parameters for the studied glasses have been obtained from differential thermal analysis (DTA) while crystalline phase fractions in the sintered glass-ceramics have been analyzed by X-ray diffraction adjoined with Rietveld refinement. Diopside, fluorapatite, wollastonite and pseudowollastonite have crystallized as the main crystalline phases in all the glass-ceramics with their content varying with respect to variation in CaO/MgO ratio in glasses. Scanning electron microscopy (SEM) has been used to shed light on the microstructure of glass-ceramics. The possible implications of structure and sintering behaviour of glasses on their bioactivity have been discussed.

Kansal, Ishu; Goel, Ashutosh; Tulyaganov, Dilshat U.; Rajagopal, Raghu R.; Ferreira, Jose M.

2012-08-01

60

Effect of heat treatment on the properties of SiO2-CaO-MgO-P 2O 5 bioactive glasses.  

PubMed

Since the invention of 45S5 Bioglass, researchers never stopped exploring new generation bioactive glass (BG) materials for wider applications in regenerative medicine, among which a novel SiO(2)-CaO-MgO-P(2)O(5) bioactive glass (BG20) is an excellent candidate. However, apart from their biocompatibility and bioactivity, a porous structure is also a must for a tissue engineering scaffold in successfully fixing bone defect. The porosity is the outcome of the high temperature (500-1,000 °C) treatment in the fabricating process of the bioglass scaffold. Under the high temperature, the amorphous glass material will become crystallized at certain percentage in the glass matrix, and possibly leading to consequent changes in the mechanical strength, biodegradability and bioactivity. To elucidate the effect of phase transition on the change of the properties of BG20, the experiments in this report were designed to fine-tuning the heat treating temperatures to fabricate a series of BG20 powders with different crystallization structures. X-ray diffraction revealed a positive correlation between the heating temperature and the crystallization, as well as the compressive strength of the materials. In vitro degradation and ion analysis by ICP-AES demonstrated a similar releasing behavior of different ions including Mg(2+), Ca(2+) and Si(4+), which in common is the tendency of decreasing of the ion concentration along with the increasing of the treating temperature. Cell proliferation assay using both mouse fibroblasts (NIH3T3) and bone marrow stromal cells (BMSCs) showed little toxicity of the ionic extract of the BG20 powders at all the treating temperatures, while fibroblasts demonstrated a significant promoting in the percentage of proliferation. Furthermore, reverse-transcription and polymerase chain reaction analysis on two representative marker genes for early osteogenesis and endochondral ossification, respectively, type I collagen alpha 1 and Indian Hedge-hog, showed an interesting induction of both genes over their basal levels by the treatment of the ionic extract of BG20, implying its important capability in regulating the fate of differentiation of the BMSCs as a novel biomaterial in bone tissue engineering. PMID:22699712

Zhou, Yue; Li, Hongying; Lin, Kaili; Zhai, Wanying; Gu, Weiming; Chang, Jiang

2012-09-01

61

Compositional and microstructural design of highly bioactive P2O5-Na2O-CaO-SiO2 glass-ceramics.  

PubMed

Bioactive glasses having chemical compositions between 1Na(2)O-2CaO-3SiO(2) (1N2C3S) and 1.5Na(2)O-1.5CaO-3SiO(2) (1N1C2S) containing 0, 4 and 6 wt.% P(2)O(5) were crystallized through two stage thermal treatments. By carefully controlling these treatments we separately studied the effects on the mechanical properties of two important microstructural features not studied before, crystallized volume fraction and crystal size. Fracture strength, elastic modulus and indentation fracture toughness were measured as a function of crystallized volume fraction for a constant crystal size. Glass-ceramics with a crystalline volume fraction between 34% and 60% exhibited a three-fold improvement in fracture strength and an increase of 40% in indentation fracture toughness compared with the parent glass. For the optimal crystalline concentration (34% and 60%) these mechanical properties were then measured for different grain sizes, from 5 to 21 ?m. The glass-ceramic with the highest fracture strength and indentation fracture toughness was that with 34% crystallized volume fracture and 13 ?m crystals. Compared with the parent glass, the average fracture strength of this glass-ceramic was increased from 80 to 210 MPa, and the fracture toughness from 0.60 to 0.95 MPa.m(1/2). The increase in indentation fracture toughness was analyzed using different theoretical models, which demonstrated that it is due to crack deflection. Fortunately, the elastic modulus E increased only slightly; from 60 to 70 GPa (the elastic modulus of biomaterials should be as close as possible to that of cortical bone). In summary, the flexural strength of our best material (215 MPa) is significantly greater than that of cortical bone and comparable with that of apatite-wollastonite (A/W) bioglass ceramics, with the advantage that it shows a much lower elastic modulus. These results thus provide a relevant guide for the design of bioactive glass-ceramics with improved microstructure. PMID:22032913

Peitl, Oscar; Zanotto, Edgar D; Serbena, Francisco C; Hench, Larry L

2012-01-01

62

Luminescence properties of Sm3+-doped P2O5-PbO-Nb2O5 glass under high pressure  

NASA Astrophysics Data System (ADS)

Samarium doped lead phosphate glass modified with niobium having a composition (in mol%) of 55P2O5+39.5PbO+5Nb2O5+0.5Sm2O3 has been prepared by the conventional melt quenching technique. The emission spectra and the decay curves for the 4G5/2 level of Sm3+ 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 \\mathrm {{}^{4}G_{5/2}} \\to \\mathrm {{}^{6}H_{5/2}} , 6H7/2 and 6H9/2 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 \\mathrm {{}^{4}G_{5/2}} \\to \\mathrm {{}^{6}H_{5/2}} and \\mathrm {{}^{4}G_{5/2}} \\to \\mathrm {{}^{6}H_{7/2}} Stark levels with pressure is observed in phase 1 than in phase 2. The lifetime of the 4G5/2 level decreases from 2.29 ms (0 GPa) to 0.64 ms (23.6 GPa) with pressure. The decay curves of the 4G5/2 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 Sm3+ ions in the title glass are found to be larger than those found in borate, K-Ba-Al phosphate and tellurite glasses.

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

2009-01-01

63

Electrochemical studies on solid state cells with mol % 70AgI20Ag 2 O-10(0.8V 2 O 5 -0.2P 2 O 5 ) amorphous electrolyte and organic cathodes  

Microsoft Academic Search

The highest conducting amorphous solid electrolyte composition (mol %) 70AgI-20Ag2O-10(0.8V2O5-0.2P2O5) in the system AgI-Ag2O-V2O5-P2O5 was investigated as an electrolyte material for solid state cells with organic cathodes by studying the electrochemical properties. The variation of open circuit voltage (OCV) with temperature, current discharge and the load characteristics were determined for the cells with iodine, tetramethyl ammonium iodide and tetrabutyl ammonium

P. Sathya Sainath Prasad; S. Radhakrishna

1989-01-01

64

A 90-day intravenous administration toxicity study of CaO-SiO2-P2O5-B2O3 glass-ceramics (BGS-7) in rat.  

PubMed

CaO-SiO(2)-P(2)O(5)-B(2)O(3) glass ceramics directly bond to bone and have potential use as a bone substitute material. The present study evaluated the toxicity from subchronic intravenous administration of CaO-SiO(2)-P(2)O(5)-B(2)O(3) glass ceramics to male and female Sprague-Dawley rats. The rats were divided into four groups, each consisting of 10 male and 10 female rats, and administered different amounts of CaO-SiO(2)-P(2)O(5)-B(2)O(3) glass ceramics (aqueous extract 5, 2.5, and 1.25 mL/kg body weight/day and saline) 7 days per week for 90 consecutive days. During the experiment, no deaths were observed in any groups, and there were no remarkable changes in clinical signs, body weight, food and water intake, hematological and serum biochemical parameters, organ weight, and histopathological findings between the control and treated groups. The results show no adverse toxic effects of CaO-SiO(2)-P(2)O(5)-B(2)O(3) glass ceramics (aqueous extract 5 mL/kg body weight/day) to rats of either sex. PMID:19995308

Lee, Jae Hyup; Ryu, Hyun-Seung; Seo, Jun-Hyuk; Chang, Bong-Soon; Lee, Choon-Ki

2010-01-01

65

Coarsening of needle-shaped apatite crystals in SiO2 • Al2O3 • Na2O • K2O • CaO • P2O5 • F glass  

Microsoft Academic Search

Coarsening of needle-shaped apatite crystals was studied in a SiO2 • Al2O3 • Na2O • K2O • CaO • P2O5 • F glass. Crystal numbers and size distributions were measured by image analysis of electron micrographs obtained from slightly etched fractures of powder compacts sintered from differently annealed glass powders. Results indicate that the growth of apatite needles is controlled

R. Müller; L. A. Abu-Hilal; S. Reinsch; W. Höland

1999-01-01

66

Effect of partial crystallization on the mechanical properties and cytotoxicity of bioactive glass from the 3CaO.P(2)O(5)-SiO(2)-MgO system.  

PubMed

The aim of this study is to report on the development and characterization of bioactive glass and glass-ceramics from the 3CaO.P(2)O(5)-SiO(2)-MgO-system, using different degrees of cristallinity for applications as an implant material. A methodology was proposed to induce crystallization of phases. Bioglass samples of the nominal composition (wt %) 57.75 CaO.P(2)O(5)-30 SiO(2)-17.25MgO were heat treated at temperatures ranging from 700 to 1100°C for 4h. The findings from the research illustrate how partial crystallization and phase transformations modified the microstructure of the based glassy material, resulting in improved mechanical properties. The maximum gain was measured for samples treated at 975°C, having a hardness of 6.2GPa, an indentation fracture toughness of 1.7MPam(1/2) and a bending strength of 120MPa, representing an increase of 30, 55 and 70%, respectively, when compared to the nucleated glass. The highest elastic modulus of about 130GPa was determined for samples treated at 1100°C. As a preliminary biological evaluation, "in vitro" cytotoxicity tests were realized to determine the cytotoxic level of the materials, using the neutral red uptake method with NCTC clones L929 from the American Type Culture Collection (ATCC) bank. On the other hand, no significant influence of the partial crystallization on cytotoxicity was observed. The results provide support for implant materials based on the 3CaO.P(2)O(5)-SiO(2)-MgO-system. PMID:22975418

Daguano, J K M F; Strecker, K; Ziemath, E C; Rogero, S O; Fernandes, M H V; Santos, C

2012-10-01

67

Phase Relationship of CaO-SiO2-FeO-5 mass pct P2O5 System with Low Oxygen Partial Pressure at 1673 K (1400 °C)  

NASA Astrophysics Data System (ADS)

Dephosphorization by using multiphase flux could considerably decrease the consumption of CaO and prevent the addition of fluorite. However, the equilibrium phase relationship within this system, which is of significant importance for understanding the formation mechanism of multiphase flux, remains unclear. Thus, it is required to provide reliable phase diagrams of the basic slag system of multiphase flux. In this research, the phase relationship of the CaO-SiO2-FeO-5 mass pct P2O5 system at 1673 K (1400 °C) with {P}_{{{{O}}2 }} of 9.24 × 10-11 atm has been studied by using the chemical equilibration method. It has been found that solid solution consists mainly of 2CaO·SiO2-3CaO·P2O5, but occasionally it contains 3CaO·SiO2. Liquidus saturated with solid solution shrinks toward the FeO corner compared with the isothermal at 1673 K (1400 °C) of the CaO-SiO2-FeO system equilibrated with metallic iron. Thermodynamically stable CaO-FeO phase is confirmed, which could promote the condensation of 3CaO·P2O5 into the solid solution and increase the phosphorus partition ratio between the solid solution and molten slag. Based on the regular solution model, the effect of T.Fe and CaO content in the liquid phase on the phosphorus partition ratio between the solid solution and molten slag is discussed.

Gao, Xu; Matsuura, Hiroyuki; Sohn, Il; Wang, Wanlin; Min, Dong Joon; Tsukihashi, Fumitaka

2012-08-01

68

Thermophysical Properties of Ceramic Filler-Added BaO–ZnO–B 2 O 3 –P 2 O 5 Glass Composites for Barrier Ribs of Plasma Display Panels  

Microsoft Academic Search

The capability of BaO–ZnO–B2O3–P2O5 glass in hosting various ceramic fillers (up to 20 mass% of Al2O3, TiO2, and ZnO) has been investigated. All the investigated filler-added glasses have demonstrated a reasonable densification at\\u000a 550 °C to form stable ceramic filler-glass composites. Modifications of the thermophysical properties, such as coefficient\\u000a of thermal expansion (CTE), glass transition temperature, and dilatometric softening temperature, by the

Eugene Chong; Seongjin Hwang; Wookyung Sung; Hyunho Shin; Hyungsun Kim

2010-01-01

69

Formation of hydroxyapatite onto glasses of the CaO-MgO-SiO2 system with B2O3, Na2O, CaF2 and P2O5 additives.  

PubMed

New bioactive glasses with compositions based on the CaO-MgO-SiO(2) system and additives of B(2)O(3), P(2)O(5), Na(2)O, and CaF(2) were prepared. The in vitro mineralization behaviour was tested by immersion of powders or bulk glasses in simulated body fluid (SBF). Monitoring of ionic concentrations in SBF and scanning electron microscopy (SEM) observations at the surface of the glasses were conducted over immersion time. Raman and infrared (IR) spectroscopy shed light on the structural evolution occurring at the surface of the glasses that leads to formation of hydroxyapatite. PMID:16309741

Agathopoulos, S; Tulyaganov, D U; Ventura, J M G; Kannan, S; Karakassides, M A; Ferreira, J M F

2006-03-01

70

In vitro bioactivity and crystallization behavior of bioactive glass in the system SiO 2 -CaO-Al 2 O 3 -P 2 O 5 Na 2 O-MgO-CaF 2  

Microsoft Academic Search

In this study, bioactivity of glass in the system SiO2-CaO-Al2O3-P2O5-Na2O-MgO-CaF2 was investigated. For this purpose, a glass sample was prepared by the traditional melting method. Crystallization behavior\\u000a of bioactive glass was also investigated using differential thermal analyses. The Avrami constant of bioactive glass sample\\u000a calculated according to the Ozawa equation was 3.72 ± 0.4, which indicates bulk crystallization. Using the

Melek Erol

2010-01-01

71

Influence of the Ca\\/P ratio on the morphology of fluorapatite crystals in SiO 2–Al 2O 3–CaO–P 2O 5–K 2O–F ? glass-ceramics  

Microsoft Academic Search

The formation of fluorapatite crystals with needle-like morphology was studied in glass-ceramics (GCs) of the system SiO2–Al2O3–CaO–P2O5–K2O–F?. X-ray diffraction (XRD), 31P and 27Al nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), temperature-dependent electric conductance measurements, and transmission electron microscopy (TEM) with energy dispersive X-ray analysis were used to study the influence of the Ca\\/P ratio of the starting glass composition

C. Moisescu; T. Höche; G. Carl; R. Keding; C. Rüssel; W. D. Heerdegen

2001-01-01

72

Investigations of systems ThO 2–MO 2–P 2O 5 (M=U, Ce, Zr, Pu). Solid solutions of thorium–uranium (IV) and thorium–plutonium (IV) phosphate–diphosphates  

Microsoft Academic Search

In the framework of nuclear waste management aiming at the research of a storage matrix, the chemistry of thorium phosphates has been completely re-examined. In the ThO2–P2O5 system a new compound thorium phosphate–diphosphate Th4(PO4)4P2O7 has been synthesized. The replacement of Th4+ by a smaller cation like U4+ and Pu4+ in the thorium phosphate–diphosphate (TPD) lattice has been achieved. Th4?xUx(PO4)4P2O7 and

N. Dacheux; R. Podor; V. Brandel; M. Genet

1998-01-01

73

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

PubMed

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

Siqueira, Renato Luiz; Zanotto, Edgar Dutra

2013-02-01

74

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

NASA Astrophysics Data System (ADS)

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 d 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.

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

2012-04-01

75

Synthesis and characterization of phosphates in molten systems Cs 2O–P 2O 5–CaO– M III 2O 3 ( M III—Al, Fe, Cr)  

Microsoft Academic Search

The crystallization of complex phosphates from the melts of Cs2O–P2O5–CaO–MIII2O3 (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 ??\\/?=0.2 and Ca\\/?III=1. The fields of crystallization of CsCaP3O9, ?-Ca2P2O7, Cs2CaP2O7, Cs3CaFe(P2O7)2, Ca9MIII(PO4)7 (MIII—Fe, Cr), Cs0.63Ca9.63Fe0.37(PO4)7 and CsCa10(PO4)7 were determined. Obtained phosphates were investigated using powder X-ray diffraction and FTIR

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

2011-01-01

76

Thermophysical Properties of Ceramic Filler-Added BaO-ZnO-B2O3-P2O5 Glass Composites for Barrier Ribs of Plasma Display Panels  

NASA Astrophysics Data System (ADS)

The capability of BaO-ZnO-B2O3-P2O5 glass in hosting various ceramic fillers (up to 20 mass% of Al2O3, TiO2, and ZnO) has been investigated. All the investigated filler-added glasses have demonstrated a reasonable densification at 550 °C to form stable ceramic filler-glass composites. Modifications of the thermophysical properties, such as coefficient of thermal expansion (CTE), glass transition temperature, and dilatometric softening temperature, by the addition of the fillers have been investigated and correlated to phase and microstructural evolution. The CTE of the fabricated composites with varying filler addition is well correlated with theoretical predictions based on the Turner equation considering the modification by phase evolution, which indicates the thermal property tuning potential of the BZBP-based glass composites for application to barrier ribs of plasma display panels.

Chong, Eugene; Hwang, Seongjin; Sung, Wookyung; Shin, Hyunho; Kim, Hyungsun

2010-10-01

77

Synthesis, bioactivity and preliminary biocompatibility studies of glasses in the system CaO-MgO-SiO2-Na2O-P2O5-CaF2.  

PubMed

New compositions of bioactive glasses are proposed in the CaO-MgO-SiO(2)-Na(2)O-P(2)O(5)-CaF(2) system. Mineralization tests with immersion of the investigated glasses in simulated body fluid (SBF) at 37°C showed that the glasses favour the surface formation of hydroxyapatite (HA) from the early stages of the experiments. In the case of daily renewable SBF, monetite (CaHPO(4)) formation competed with the formation of HA. The influence of structural features of the glasses on their mineralization (bioactivity) performance is discussed. Preliminary in vitro experiments with osteoblasts' cell-cultures showed that the glasses are biocompatible and there is no evidence of toxicity. Sintering and devitrification studies of glass powder compacts were also performed. Glass-ceramics with attractive properties were obtained after heat treatment of the glasses at relatively low temperatures (up to 850°C). PMID:21188484

Tulyaganov, D U; Agathopoulos, S; Valerio, P; Balamurugan, A; Saranti, A; Karakassides, M A; Ferreira, J M F

2011-02-01

78

Effect of ZnO addition on bioactive CaO-SiO2-P2O5-CaF2 glass-ceramics containing apatite and wollastonite.  

PubMed

Some ceramics show bone-bonding ability, i.e. bioactivity. Apatite formation on ceramics is an essential condition to bring about direct bonding to living bone when implanted into bony defects. A controlled surface reaction of the ceramic is an important factor governing the bioactivity and biodegradation of the implanted ceramic. Among bioactive ceramics, glass-ceramic A-W containing apatite and wollastonite shows high bioactivity, as well as high mechanical strength. In this study, glass-ceramics containing zinc oxide were prepared by modification of the composition of the glass-ceramic A-W. Zinc oxide was selected to control the reactivity of the glass-ceramics since zinc is a trace element that shows stimulatory effects on bone formation. Glass-ceramics were prepared by heat treatment of glasses with the general composition: xZnOx(57.0-x)CaOx35.4SiO(2)x7.2P(2)O(5)x0.4CaF(2) (where x=0-14.2mol.%). Addition of ZnO increased the chemical durability of the glass-ceramics, resulting in a decrease in the rate of apatite formation in a simulated body fluid. On the other hand, the release of zinc from the glass-ceramics increased with increasing ZnO content. Addition of ZnO may provide bioactive CaO-SiO(2)-P(2)O(5)-CaF(2) glass-ceramics with the capacity for appropriate biodegradation, as well as enhancement of bone formation. PMID:16765885

Kamitakahara, M; Ohtsuki, C; Inada, H; Tanihara, M; Miyazaki, T

2006-07-01

79

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)

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.

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

2014-03-01

80

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

PubMed

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

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

2014-01-01

81

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

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 ?-CaSiO(3). (?-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 ?-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

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

2014-06-01

82

UV spectroscopy, refractive indices and elastic properties of the (76 - x) TeO2·9P2O5·15ZnO·xLiNbO3 glass  

NASA Astrophysics Data System (ADS)

Tellurite glass with composition (76 - x) TeO2·9P2O5·15ZnO·xLiNbO3 (where x = 12.5, 25, 30 and 35 in mol%) have been prepared by melt-quenching method. The optical properties of the glass were estimated by measuring UV-VIS spectroscopy and refractive indices at different wavelength. From the absorption edge studies, the optical energy gap (Eopt) and Urbach energy (?E) has been evaluated. Moreover mechanical properties with structural properties of the glasses were investigated by measuring both longitudinal and shear velocities by using the pulse-echo overlap technique at 5 MHz. The elastic moduli such as: longitudinal (?), shear (?), bulk (B) and Young's (Y) increase with the increase in LiNbO3 content in the prepared glasses matrix. The different physical parameters such as density, molar volume, oxygen molar volume, oxygen packing density, molar polarizability, Debye temperature, microhardness, Poisson's ratio, kinetic fragility and fractal bond connectivity have been computed and were found to depend on the glass composition.

Yousef, El Sayed; Al-Qaisi, Badriah

2013-05-01

83

Optical properties of the Tm 3+ and energy transfer between Tm 3+?Pr 3+ ions in P 2O 5-CaO-SrO-BaO phosphate glass  

NASA Astrophysics Data System (ADS)

A P 2O 5-CaO-SrO-BaO phosphate glass doped with Tm 3+ and glasses doped with (Tm 3+, Pr 3+) were used for this study. The photo-luminescence behaviors of Tm 3+ and Pr 3+ in phosphate glass were investigated by absorption, excitation and emission spectroscopy. The energy transfer between Tm 3+ and Pr 3+ in phosphate glasses (which exhibit a variety of transfer efficiencies) was studied. The experimental quantum efficiencies of the luminescence of Tm 3+ ? 0 and (Tm 3+, Pr 3+) doped phosphate glasses were measured to give ?/?0 = 0.447, 0.305, and 0.179 for (0.4 mol% Pr 3+, 1.0 mol% Tm 3+), (0.8%Pr 3+, 1.0%Tm 3+) and (1.6 mol% Pr 3+, 1.0 mol% Tm 3+), respectively. In order to verify the nature of the ion coupling in our phosphate glass system, we applied the Inokuti-Hirayama model. The non-radiative energy transfer rate from Tm 3+ to Pr 3+, transfer efficiencies, and the donor-acceptor distance have been calculated and compared with obtained experimental data. As usual, the efficiency and the probability of energy transfer increase with the concentration of the acceptor.

Mazurak, Z.; Czaja, M.; Lisiecki, R.; Gabry?-Pisarska, J.

2011-01-01

84

Optical and fluorescence spectroscopy of Eu2O3-doped P2O5–K2O–KF–MO–Al2O3 (M = Mg, Sr and Ba) glasses  

NASA Astrophysics Data System (ADS)

Fluorophosphate glasses of composition, P2O5 + K2O + KF + MO + Al2O3 + xEu2O3 (M = Mg, Sr and Ba; x = 0.01, 0.05, 0.1, 1.0, 2.0, 4.0 and 6.0 mol%) were prepared and characterized their optical properties. Crystal-field (CF) analysis revealed a relatively weak CF strength around Eu3+ ions in the Ba based fluorophosphate glasses. The Judd-Ofelt parameters have been estimated from the oscillator strengths of 7F0 ? 5D2, 7F0 ? 5D4 and 7F0 ? 5L6 absorption transitions of Eu3+ ions and were used to evaluate the radiative properties of the 5D0 ? 7FJ (J = 0–4) transitions. Considerable variation has been observed in the relative intensity ratio of 5D0 ? 7F2 to 5D0 ? 7F1 transitions of Eu3+ ions due to change in the alkaline earth metal ions. The decay of the 5D0 level shows single exponential and less sensitive to Eu3+ ions concentration as well as MgO/SrO/BaO modifiers.

Kumar, K. Upendra; Babu, S. Surendra; Rao, Ch. Srinivasa; Jayasankar, C. K.

2011-06-01

85

Effect of yttria addition on mechanical, physical and biological properties of bioactive MgO-CaO-SiO2-P2O5-CaF2 glass ceramic.  

PubMed

Preparation of the bioactive MgO-CaO-SiO2-P2O5-CaF2 glass was carried out utilizing tap casting and powder metallurgy methods. The original composition was modified with 0.2% Y2O3 and carbon additions. The mother and the modified bioglass were examined, and comparative studies were performed between the mother and modified type to study the compositional modification effects on physical, mechanical and biological properties. The histology of mother type showed that this type has a good biocompatibility with no rejection or inflammation reaction with the host bone, and new bone generation and formation were shown in the region of implant. The modification with 0.2% Y2O3 achieved a good improvement in the mechanical properties when compared with the mother system. The histology of this type showed a normal acceptance with no inflammation reactions. On the other hand, the modification with carbon achieved a superior improvement in the mechanical properties compared to the mother bioglass and showed a good acceptance with no inflammation reactions with the host body as well. PMID:18458492

Al-Haidary, J; Al-Haidari, M; Qrunfuleh, S

2008-03-01

86

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

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

87

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

PubMed

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

Li, Guangda; Feng, Shuying; Zhou, Dali

2011-10-01

88

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

PubMed Central

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.

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

2014-01-01

89

Influence of strontium on structure, sintering and biodegradation behaviour of CaO-MgO-SrO-SiO(2)-P(2)O(5)-CaF(2) glasses.  

PubMed

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 the composition (mol.%): (36.07 - x) CaO-xSrO-19.24MgO-5.61P(2)O(5)-38.49SiO(2)-0.59CaF(2), where x varies between 0 and 10. The detailed structural analysis of the glasses is made by infrared spectroscopy and magic angle spinning-nuclear magnetic resonance spectroscopy. Silicon is predominantly present as Q(2) (Si) species, while phosphorus is found as orthophosphate in all the investigated glasses. The apatite-forming ability of glasses is investigated by immersion of glass powders in simulated body fluid for time durations varying between 1 h and 7 days. While increasing the Sr(2+)/Ca(2+) ratio in the glasses does not affect their structure significantly, their apatite-forming ability is decreased considerably. Further, physico-chemical degradation of glasses is 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 the ion release profiles from the glasses in different solutions are discussed. The addition of strontium to the glasses leads to a sevenfold decrease in chemical degradation of glasses in Tris-HCl. The sintering of glass powders renders glass ceramics (GCs) with varying degrees of crystallinity and good flexural strength (98-131 MPa), where the mechanical properties depend on the nature and amount of crystalline phases present in the GCs. PMID:21763793

Goel, Ashutosh; Rajagopal, Raghu Raman; Ferreira, José M F

2011-11-01

90

Optical absorption and fluorescence spectral studies of Sm3+ ion in BaO-M2O3 (M = Ga, Al, In)-P2O5 glass systems  

NASA Astrophysics Data System (ADS)

BaO-P2O5 glasses mixed with three IIIA group metal oxides viz., Al2O3, Ga2O3 and In2O3 doped with Sm2O3 were prepared. Optical absorption and photoluminescence spectra of these glasses have been studied. The absorption spectra of these glasses have revealed the absorption bands due to 6H5/2 ? 4I11/2, 4I13/2, 4G9/2, 6P5/2, 4F7/2, 6P7/2, 4D5/2, 4K17/2 transitions. By performing least square fit analysis, the Judd-Ofelt intensity parameters ?? for these glasses were evaluated; these parameters have exhibited the following trend: ?2 > ?4 >?6. The photoluminescence spectra with the excitation wavelength 400 nm recorded at room temperature of these glasses have exhibited the following emission transitions: 4G5/2 ? 6H5/2, 6H7/2, 6H9/2. From luminescence spectra, various radiative properties like transition probability A, branching ratio ?r, the radiative lifetime ?r and the emission cross-section ?E for various emission levels of these glasses have been determined and reported. Out of the three J-O parameters (??), the value of ?2 which is related to the structural changes in the vicinity of the Sm3+ ion indicated the highest covalent environment of Sm3+ ion in indium mixed glasses. The luminescence spectra of all the three glasses suggested the highest of values of transition probability 4G4 ? 6H9/2 in BGPSm glasses. The analysis of these results further indicted comparatively high non-radiative losses in In2O3 mixed glasses.

Prasad, S. V. G. V. A.; Lakshmana Rao, B.

2009-07-01

91

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

NASA Astrophysics Data System (ADS)

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.

Gle?, M.; Grzmil, B.

2011-05-01

92

Electrical conductivity, TEP and dielectric studies on mol% 66.6 Agl-22.2 Ag 2 O-11.1 (0.8 V 2 O 5 -0.2 P 2 O 5 ) electrolyte material for solid state batteries  

Microsoft Academic Search

In the superionic conducting quarternary system Agl-Ag2O-V2O5-P2O5, the best ionic conductivity was obtained for the composition 66.6% Agl-33.3% (2Ag2O-1 (V2O5-P2O5)), when the GF\\/GM ratio was varied from 0.20 to 5.0. Then fixing the GF\\/GM ratio at 0.50, the ratio of the glass formers V2O5 and P2O5 were varied and the highest conducting composition was obtained as 66.6% Agl-22.2 Ag2O-11.1% (0.8

P. Sathya Sainath Prasad; S. Radhakrishna

1988-01-01

93

Fabrication and evaluation of osteoblastic differentiation of human mesenchymal stem cells on novel CaO-SiO2-P2O5-B2O3 glass-ceramics.  

PubMed

Apatite-wollastonite glass-ceramics have high mechanical strength, and CaO-SiO2 -B2 O3 glass-ceramics showed excellent bioactivity and high biodegradability. A new type of CaO-SiO2 -P2 O5 -B2 O3 system of bioactive glass-ceramics (BGS-7) was fabricated, and the effect and usefulness was evaluated via bioactivity using simulated body fluid and human mesenchymal stem cells (hMSCs). The purpose of this study was to compare BGS-7 and hydroxyapatite (HA) using hMSCs in order to evaluate the bioactivity of BGS-7 and its possibility as a bone graft extender. Alkaline phosphatase (ALP) staining, ALP activity, cell proliferation 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, Alizarin Red-S (AR-S) staining, calcium levels, the mRNA expression of ALP, osteocalcin, osteopontin, and runt-related transcription factor 2 (runx-2) using reverse-transcription polymerase chain reaction (RT-PCR) and the protein expression of osteocalcin and runx-2 using Western blot were measured by transplanting hMSC onto a tissue culture plate, HA, and BGS-7. The ALP staining and AR-S staining of BGS-7 was greater than that of HA and control. The ALP value of BGS-7 was significantly higher than that of HA and control. The MTS results showed that BGS-7 had a higher value than the groups transplanted onto HA and control on day 15. The calcium level was higher than the control in both HA and BGS-7, and was especially high in BGS-7. There were more mineral products on BGS-7 than on the HA when analyzed by scanning electron microscopy. The mRNA expression of ALP, osteopontin, osteocalcin, and runx-2 were higher on BGS-7 than on HA and the control when analyzed by RT-PCR. The relative gene expression of osteopontin and runx-2 were found to be higher on BGS-7 than on HA and the control by Western blot. Accordingly, it is predicted that BGS-7 would have high biocompatibility and good osteoconductivity, and presents a possibility as a new bone graft extender. PMID:23560457

Lee, Jae Hyup; Seo, Jun-Hyuk; Lee, Kyung Mee; Ryu, Hyun-Seung; Baek, Hae-Ri

2013-07-01

94

A Thermodynamic Model of Phosphorus Distribution Ratio between CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 Slags and Molten Steel during a Top-Bottom Combined Blown Converter Steelmaking Process Based on the Ion and Molecule Coexistence Theory  

NASA Astrophysics Data System (ADS)

A thermodynamic model for calculating the phosphorus distribution ratio between top-bottom combined blown converter steelmaking slags and molten steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and molten steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of molten steel at the slag-metal interface or the Fe t O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with molten steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O in the slags. A significant difference of dephosphorization ability among Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter steelmaking process, respectively. There is a great gradient of oxygen activity of molten steel at the slag-metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in molten steel beneath the slag-metal interface can be extracted effectively by the comprehensive effect of CaO and Fe t O in slags to form 3CaO·P2O5 and 4CaO·P2O5 until the carbon content is less than 0.036 pct during a top-bottom combined blown steelmaking process.

Yang, Xue-Min; Duan, Jian-Ping; Shi, Cheng-Bin; Zhang, Meng; Zhang, Yong-Liang; Wang, Jian-Chang

2011-08-01

95

Effect of Li 2O on the structure, electrical and dielectric properties of xLi 2O·(20- x)CaO·30P 2O 5·30V 2O 5·20Fe 2O 3 glasses  

NASA Astrophysics Data System (ADS)

Glasses of the general formula xLi 2O·(20- x)CaO·30P 2O 5·30V 2O 5·20Fe 2O 3 with x=0, 5, 10, 15 and 20 mol% were prepared; IR, density, electrical and dielectric properties have been investigated. Lithia-containing glasses revealed more (P 2O 7) 4-, FeO 6, V-O - and PO - groups and mostly have lower densities than those of lithia-free ones. The electrical properties showed random behavior by replacing Li 2O for CaO, which has been assigned to the change of the glass structure. The results of activation energy and frequency-dependent conductivity indicate that the conduction proceeds via electronic and ionic mechanisms, the former being dominant. The mechanism responsible for the electronic conduction is mostly thermally activated hopping of electrons from Fe(II) ions to neighboring Fe(III) sites and/or from V 4+ to V 5+. The dielectric constant ( ??) showed values that depend on the structure of glass according to its content of Li 2O. The ( ??) values are ranging between 3 and 41 at room temperature for 1 kHz, yet at high temperatures, glass with 20 mol Li 2O exhibits values of 110 and 3600 when measurement was carried out in the range 0.1-1 kHz, and at 5 MHz, respectively.

Morsi, R. M. M.; Ibrahiem, S.

2011-08-01

96

Theoretical insight into electronic structures and spectroscopic properties of [Pt2(pop)4]4-, [Pt2(pcp)4]4-, and related derivatives (pop = P2O5H2(2-) and pcp = P2O4CH4(2-)).  

PubMed

The structures of [Pt2(pop)4]4-, [Pt2(pcp)4]4-, and related species [Pt2(pop)4X2]4- and [Pt2(pop)4]2- in the ground states (pop = P2O5H2(2-), pcp = P2O4CH4(2-), and X = I, Br, and Cl) were optimized using the second-order Møller-Plesset perturbation (MP2) method. It is shown that the Pt-Pt distances decrease in going from [Pt2(pop)4]4- to [Pt2(pop)4X2]4- to [Pt2(pop)4]2-. This is supported by the analyses of their electronic structures. The calculated aqueous absorption spectra at the time-dependent density functional theory (TD-DFT) level agree with experimental observations. The unrestricted MP2 method was employed to optimize the structures of [Pt2(pop)4]4- and [Pt2(pcp)4]4- in the lowest-energy triplet excited states. The Pt-Pt contraction trend is well reproduced in these calculations. For [Pt2(pop)4]4-, the Pt-Pt distance decreases from 2.905 A in the ground state to 2.747 A in the excited state, which is comparable to experimental values of 2.91-2.92 A and 2.64-2.71 A, respectively. On the basis of the excited-state structures of such complexes, TD-DFT predicts the solution emissions at 480 and 496 nm, which is closer to the experimental values of 512 and 510 nm emissions, respectively. PMID:17029384

Pan, Qing-Jiang; Fu, Hong-Gang; Yu, Hai-Tao; Zhang, Hong-Xing

2006-10-16

97

A neutron diffraction and 27Al MQMAS NMR study of rare-earth phosphate glasses, (R2O3)x(P2O5)1-x, x = 0.187-0.263, R = Ce, Nd, Tb containing Al impurities  

NASA Astrophysics Data System (ADS)

A neutron diffraction study of four rare-earth phosphate glasses of composition (R2O3)x(P2O5)1-x, where x = 0.197, 0.235, 0.187, 0.263 and R = Ce, Ce, Nd, Tb respectively is presented. The structures of these materials were investigated as a function of (a) rare-earth atomic number and (b) composition. The results show that samples containing the larger rare-earth ions (Ce3+ and Nd3+) are coordinated to seven oxygen atoms whereas the immediate environment of Tb3+ ions is six coordinate. This implies that rare-earth clustering must be present in the samples containing larger rare-earth ions although no R ... R correlations are directly observed. Terminal and bridging P-O correlations are resolved, existing in an approximately 1:1 ratio. Second-neighbour O(P)O separations are located with good accuracy and P(O)P correlations relating to the bridging chain are observed. There is also first evidence for the third neighbour correlation, P(OP)O, at ~2.8 Å. A residual feature in the neutron diffraction data, present at ~1.8 Å, is interpreted as Al-O correlations on the basis of 27Al MQMAS NMR experiments. This aluminium impurity originates from the use of aluminium oxide crucibles used in the glass synthesis and is shown to exist as a mixture of octahedral, tetrahedral and penta-coordinated Al-O species. No structural perturbations of the overall network were observed with varying sample composition.

Cole, Jacqueline M.; van Eck, Ernst R. H.; Mountjoy, Gavin; Newport, Robert J.; Brennan, Tessa; Saunders, George A.

1999-11-01

98

Enhanced osteocalcin expression by osteoblast-like cells (MC3T3-E1) exposed to bioactive coating glass (SiO2-CaO-P2O5-MgO-K2O-Na2O system) ions.  

PubMed

This study tested the hypothesis that bioactive coating glass (SiO(2)-CaO-P(2)O(5)-MgO-K(2)O-Na(2)O system), used for implant coatings, enhanced the induction of collagen type 1 synthesis and in turn enhanced the expression of downstream markers alkaline phosphatase, Runx2 and osteocalcin during osteoblast differentiation. The ions from experimental bioactive glass (6P53-b) and commercial Bioglass(TM) (45S5) were added to osteoblast-like MC3T3-E1 subclone 4 cultures as a supplemented ion extract (glass conditioned medium (GCM)). Ion extracts contained significantly higher concentrations of Si and Ca (Si, 47.9+/-10.4 ppm; Ca, 69.8+/-14.0 for 45S5; Si, 33.4+/-3.8 ppm; Ca, 57.1+/-2.8 ppm for 6P53-b) compared with the control extract (Si<0.1 ppm, Ca 49.0 ppm in alpha-MEM) (ANOVA, p<0.05). Cell proliferation rate was enhanced (1.5x control) within the first 3 days after adding 45S5 and 6P53-b GCM. MC3T3-E1 subclone 4 cultures were then studied for their response to the addition of test media (GCM and control medium along with ascorbic acid (AA; 50 ppm)). Each GCM+AA treatment enhanced collagen type 1 synthesis as observed in both gene expression results (day 1, Col1alpha1, 45S5 GCM+AA: 3x control+AA; 6P53-b GCM+AA: 4x control+AA; day 5, Col1alpha2, 45S5 GCM+AA: 3.15x control+AA; 6P53-b GCM+AA: 2.35x control+AA) and in histological studies (Picrosirius stain) throughout the time course of early differentiation. Continued addition of each GCM and AA treatment led to enhanced expression of alkaline phosphatase (1.4x control+AA after 5 days, 2x control+AA after 10 days), Runx2 (2x control+AA after 7 days) and osteocalcin gene (day 3, 45S5 GCM+AA: 14x control+AA; day 5, 6P53-b GCM+AA: 19x control+AA) and protein expression (40x-70x control+AA after 6 days). These results indicated the enhanced effect of bioactive glass ions on key osteogenic markers important for the bone healing process. PMID:19497391

Varanasi, V G; Saiz, E; Loomer, P M; Ancheta, B; Uritani, N; Ho, S P; Tomsia, A P; Marshall, S J; Marshall, G W

2009-11-01

99

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)

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.

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

1995-11-01

100

DC electrical conductivity of Li 2O–CdO–P 2O 5 glasses  

Microsoft Academic Search

The DC electrical conductivity as a function of Li2O\\/CdO has been measured on the lithium–cadmium–phosphate glasses which is in the range 9.20×10?15–4.83×10?10mhocm?1. The barrier lowering coefficient ? has been determined which lies between 0.76×10?4 and 0.55×10?4(eVcm1\\/2V?1\\/2). The temperature-dependent conductivity of these glasses has been examined in the temperature range 303–473K. It reveals that the activation energy of these glasses lies

M Altaf; M. A Chaudhry; S. A Siddiqi

2001-01-01

101

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

102

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

NASA Astrophysics Data System (ADS)

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 ? 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.

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

2012-06-01

103

Spectroscopic studies on Pb 3 O 4 -ZnO-P 2 O 5 glasses doped with transition metal ions  

NASA Astrophysics Data System (ADS)

Optical absorption, Electron Paramagnetic Resonance (EPR) studies are carried out on lead zinc phosphate glass systems doped with Cr 3+ and VO 2+. From optical absorption investigations the crystal-field parameters Dq, B and C are evaluated. EPR measurements on Cr 3+ systems indicate that Cr 3+ ions are located at sites with low symmetry. EPR spectra of vanadyl doped system revealed the characteristic nature of vanadyl ion. Spin-Hamiltonian and hyperfine values are evaluated for both the systems. Optical absorption spectra of vanadyl doped system revealed three bands that are characteristic of VO(II) ion in tetragonally distorted octahedral site. By correlating both EPR and optical data, the dipolar coupling constant ( P) and Fermi-constant coupling parameter ( ?) and molecular orbital coefficients ?*2, e?*2 are evaluated. Electron Paramagnetic Resonance and optical absorption studies showed that the chemical bonds of Cr 3+ ions and VO 2+ ions with the ligands have more covalent nature. From these studies it is also observed that lead spinals are playing major key role in sustaining the covalent nature of bonding.

Giridhar, G.; Sreehari Sastry, S.; Rangacharyulu, M.

2011-11-01

104

Thin film amorphous electrolytes: The Li2O-SiO2-P2O5 system.  

National Technical Information Service (NTIS)

Thin film amorphous electrolytes with compositions xLi(sub 2)O: ySiO(sub 2):zP(sub 2)O(sub 5) were deposited by single and dual source rf magnetron sputtering and their compositions determined by electron and ion beam techniques. Films containing P but no...

J. B. Bates N. J. Dudney B. C. Sales R. A. Zuhr G. R. Gruzalski

1991-01-01

105

Relación de los cultivos modificados genéticamente con el ambiente y la salud de la población costarricense  

Microsoft Academic Search

Relationship of genetically modified crops with the environment and health of the Costa Rican human population. Genetic engineering and the food derived from genetically modified crops (GMCs) have been the center of debate worldwide, as has occurred historically with the advent of new technologies. Questions are derived from the potential impact of GMCs to the environment and the safety of

Ana M. Espinoza; Griselda Arrieta-Espinoza; Ana Sittenfeld

2004-01-01

106

Phase relations in the MgO-P2O5-H2O system and the stability of phosphoellenbergerite: petrological implications  

NASA Astrophysics Data System (ADS)

The polymorphic relations for Mg3(PO4)2 and Mg2PO4OH have been determined by reversed experiments in the temperature-pressure (T-P) range 500-1100°C, 2-30 kbar. The phase transition between the low-pressure phase farringtonite and Mg3(PO4)2-II, the Mg analogue of sarcopside, is very pressure dependent and was tightly bracketed between 625°C, 7 kbar and 850°C, 9 kbar. The high-temperature, high-pressure polymorph, Mg3(PO4)2-III, is stable above 1050°C at 10 kbar and above 900°C at 30 kbar. The low-pressure stability of farringtonite is in keeping with its occurrence in meteorites. The presence of iron stabilizes the sarcopside-type phase towards lower P. From the five Mg2PO4OH polymorphs only althausite, holtedahlite, ?-Mg2PO4OH (the hydroxyl analogue of wagnerite) and ?-Mg2PO4OH were encountered. Relatively speaking, holtedahlite is the low-temperature phase (<600°C), ?-Mg2PO4OH the high-temperature, low-pressure phase and ?-Mg2PO4OH the high-temperature, high-pressure phase, with an intervening stability field for althausite which extends from about 3 kbar at 500°C to about 12kbar at 800°C. Althausite and holtedahlite are to be expected in F-free natural systems under most geological conditions; however, wagnerite is the most common Mg-phosphate mineral, implying that fluorine has a major effect in stabilizing the wagnerite structure. Coexisting althausite and holtedahlite from Modum, S. Norway, show that minor fluorine is strongly partitioned into althausite (KDF/OH 4) and that holtedahlite may incorporate up to 4 wt% SiO2. Synthetic phosphoellenbergerite has a composition close to (Mg0.9?0.1)2Mg12P8O38H8.4. It is a high-pressure phase, which breaks down to Mg2PO4OH+Mg3(PO4)2+H2O below 8.5 kbar at 650°C, 22.5 kbar at 900°C and 30 kbar at 975°C. The stability field of the phosphate end-member of the ellenbergerite series extends therefore to much lower P and higher T than that of the silicate end-members (stable above 27 kbar and below ca. 725°C). Thus the Si/P ratio of intermediate members of the series has a great barometric potential, especially in the Si-buffering assemblage with clinochlore+talc+kyanite +rutile +H2O. Application to zoned ellenbergerite crystals included in the Dora-Maira pyrope megablasts, western Alps, reveals that growth zoning is preserved at T as high as 700-725°C. However, the record of attainment of the highest T and/or of decreasing P through P-rich rims (1 to 2 Si pfu) is only possible in the presence of an additional phosphate phase (OH-bearing or even OH-dominant wagnerite in these rocks), otherwise the trace amounts of P in the system remain sequestered in the core of Si-rich crystals (5 to 8 Si pfu) and can no longer react.

Brunet, Fabrice; Chopin, Christian; Seifert, Friedrich

107

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)

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.

Jones, J. H.; Walker, D.

1993-01-01

108

Clusters dissolution of Yb3+ in codoped SiO2-Al2O3-P2O5 glass fiber and its relevance to photodarkening.  

PubMed

Using a combination of pulse electron paramagnetic resonance and photoluminescence spectroscopy, we demonstrate the major role of phosphorous rather than aluminium in the rare-earth dissolution process, an essential advance in telecommunication and solid laser fields. Our results also provide new insight into the micro-structural origin of the photodarkening process occurring in Yb doped fiber. PMID:22239785

Deschamps, T; Ollier, N; Vezin, H; Gonnet, C

2012-01-01

109

Fluorescence and Judd–Ofelt analysis of Nd 3+ doped P 2O 5–Na 2O–K 2O glass  

Microsoft Academic Search

Sodium potassium phosphate glass consisting different Nd2O3 concentrations have been prepared to study the effect of Nd3+ concentration on optical absorption and fluorescence properties. From the absorption spectra, Racah (E1, E2, E3), spin-orbit (?4f) and configuration interaction (?) parameters are calculated and reported for all the Nd3+ doped glasses. Judd–Ofelt intensity parameters (?2, ?4, ?6) are evaluated and these parameters

G. N. Hemantha Kumar; J. L. Rao; K. Ravindra Prasad; Y. C. Ratnakaram

2009-01-01

110

Clusters dissolution of Yb3+ in codoped SiO2-Al2O3-P2O5 glass fiber and its relevance to photodarkening  

NASA Astrophysics Data System (ADS)

Using a combination of pulse electron paramagnetic resonance and photoluminescence spectroscopy, we demonstrate the major role of phosphorous rather than aluminium in the rare-earth dissolution process, an essential advance in telecommunication and solid laser fields. Our results also provide new insight into the micro-structural origin of the photodarkening process occurring in Yb doped fiber.

Deschamps, T.; Ollier, N.; Vezin, H.; Gonnet, C.

2012-01-01

111

Fabrication and Bioactive Evolution of Mesoporous SiO 2 -CaO-P 2 O 5 Sol-gel Glasses  

Microsoft Academic Search

In the bio-medical materials category, the bone tissue material is receives people to take. The bone tissue material not only\\u000a substitutes for the human body skeleton supports (scaffolds), but also stimulates the cell to grow, to paste attaches and\\u000a to split up. It drives the bone tissue researches from the originally organization replacement to the nowadays organization\\u000a regeneration.\\u000a \\u000a Surfactant tri-block

L. C. Chiu; P. S. Lu; I. L. Chang; L. F. Huang; C. J. Shih

112

Effect of crucible material on optical bandgap and activation energy of Na 2 O-CdO-P 2 O 5 glasses  

Microsoft Academic Search

In the sodium cadmium phosphate glasses, the effect of diffused alumina from alumina crucible has been assessed by measuring various properties such as mass density, refractive index, optical bandgap and dc conductivity. The results of measurements corresponding to glasses prepared in alumina crucible have been compared with those of glasses prepared in platinum crucible with and without adding Al2O3. The

M. Altaf; M. A. Chaudhry

2005-01-01

113

Organismos genéticamente modificados: su impacto socioeconómico en la agricultura de los países de la Comunidad Andina, Mercosur y Chile  

Microsoft Academic Search

El desarrollo de la agro-biotecnología basada en la manipulación genética permite producir variedades de cultivos agrícolas más resistentes a plagas y enfermedades y en general, promete incorporar características deseadas, tales como resistencia a sequía y heladas y mejores cualidades nutritivas. Varios estudios sugieren que la rápida difusión e implementación de los Organismos Genéticamente Modificados (OGM) o de cultivos transgénicos en

Marianne Schaper; Soledad Parada

2001-01-01

114

Activation properties of Ag+-ion conduction in bulk amorphous AgI: estimation from extrapolation of the AgI composition dependence in AgI Ag2O P2O5 glasses  

NASA Astrophysics Data System (ADS)

AgI-based fast-ion conducting glasses with very high AgI compositions from the (AgI)x(AgPO3)1-x, (AgI)x(Ag2PO3.5)1-x, and (AgI)x(Ag3PO4)1-x systems were prepared successfully by using a rapid-press quenching and a twin-roller quenching method. The ac dielectric measurements showed common relaxation properties of Ag+-ion conduction in the glasses independently of the species of the glass network formers of AgPO3, Ag2PO3.5, and Ag3PO4, and the activation energies, ??a, for Ag+-ion conduction were observed to converge upon the same magnitude of ~26 kJ mol-1 at the AgI composition limit of x = 1. This indicates the formation of amorphous AgI regions in the glasses, and the value of ??a = 26 +/- 1 kJ mol-1 estimated at x = 1 was concluded to correspond to that for bulk amorphous AgI which has never been obtained experimentally.

Hanaya, M.; Hatate, A.; Oguni, M.

2003-06-01

115

Ultraviolet\\/visible reflection spectroscopy of molten and glassy silicates (MeO n –CaO–SiO 2) and phosphates (MeO n –CaO–P 2O 5), Me n+ = Fe 3+, Mn 2+  

Microsoft Academic Search

This work deals with the reflectivity of liquid oxides (silicates and phosphates) in the ultraviolet and visible spectral range using a reflection angle of 0°. For these considerations, we have developed a spectroscopic reflection method (impulse-flash-technique). By use of this method, we can also record kinetic processes, such as crystallization processes of a supercooled glassy matrix to a crystalline equilibrium

Ingo Zebger; Frank Pfeifer; Norbert Nowack

2005-01-01

116

Nam Con Son Basin  

SciTech Connect

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.

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

1994-07-01

117

Anomalous AgI composition dependence of the thermal and dielectric properties of AgI Ag2O P2O5 glasses: evidence for the formation of amorphous AgI aggregate regions as dominating the fast Ag+ ion conduction  

NASA Astrophysics Data System (ADS)

Heat capacities of (AgI)x(Ag3PO4)1-x glasses with x = 0.70 and 0.80 were measured to estimate the jump, ?Cp, in the ?-glass transition due to freezing of the Ag+ ion rearrangement. Dielectric relaxation properties of (AgI)x(Ag2PO3.5)1-x with x = 0, 0.20, and 0.40 and (AgI)x(Ag3PO4)1-x glasses with x = 0.30 and 0.40 were examined to estimate the activation energies, ??a, along the conduction path. ?Cp was found to appear only at larger x than a critical value xc = 0.60 for (AgI)x(Ag3PO4)1-x glasses. xc, depending on the structure of the glass network former, is larger than the values of 0.35 and 0.54 for (AgI)x(AgPO3)1-x and (AgI)x(Ag2PO3.5)1-x, respectively, glasses. ??a was found to show its inflection at around the respective xc values for the (AgI)x(Ag3PO4)1-x and (AgI)x(Ag2PO3.5)1-x glasses. These observations are discussed to support the 'amorphous AgI aggregate' model for the fast Ag+ ion conduction path.

Hanaya, Minoru; Echigo, Kousuke; Oguni, Masaharu

2005-04-01

118

¡Truco Con Agua!  

NSDL National Science Digital Library

En esta actividad los aprendices aprenderán un truco de magia donde la magia es la presión del aire. Los participantes tomarán un vaso de agua medio lleno y lo taparán con un pedazo de plástico o cartón. Sosteniendo la tarjeta contra el vaso, lo voltearán boca abajo y cuando quiten la mano debajo del vaso, ¡abracadabra! no se caerá el agua. En la tira cómica, Mateo explica a los aprendices que la presión que hace el aire en todas las direcciones es la que sostiene la tarjeta.

Science, Lawrence H.

2009-01-01

119

Un Juego de Gravedad con Reconocimiento de Voz para Niños con Problemas de Lenguaje  

Microsoft Academic Search

En este trabajo presentamos un juego electrónico (Gravedad) con reconocimiento de voz para estimular a niños en edad escolar con problemas del lenguaje dislalia. Se presenta las características y elementos del juego electrónico, así como su integración con el sistema de reconocimiento de voz y los resultados de unas pruebas de usabilidad. El juego de Gravedad se desarrolló utilizando el

Carlos Miranda-Palm; Reyna Camal-U; José Cen-Magaña; Cinhtia Gonzalez-Segura; Sergio Gonzalez-Segura; Michel García; Lizzie Narvaez-Díaz

120

Opciones de cirugía para mujeres con CDIS o con cáncer de seno  

Cancer.gov

Folleto para mujeres con CDIS o con cáncer de seno que pueden operarse con cirugía. Esta guía explica los tipos de cirugía de seno, como la operación para preservar el seno y la mastectomía, y ayuda a las mujeres a decidir cuál cirugía es la mejor opción para ellas.

121

Opciones de cirugía para mujeres con CDIS o con cáncer de seno  

Cancer.gov

E-book para mujeres con CDIS o con cáncer de seno que pueden operarse con cirugía. Esta guía explica los tipos de cirugía de seno, como la operación para preservar el seno y la mastectomía, y ayuda a las mujeres a decidir cuál cirugía es la mejor opción para ellas.

122

Genetic polymorphism of CON 1 and CON 2 salivary proteins detected by immunologic and concanavalin a reactions on nitrocellulose with linkage of CON 1 and CON 2 genes to the SPC (salivary protein gene complex)  

Microsoft Academic Search

Two new genetic protein polymorphisms (CON 1 and CON 2) were identified in parotid saliva. Genetic polymorphisms of salivary CON 1 (concanavalin A) and CON 2 proteins are determined by autosomal inheritance of one expressed (dominant) and one unexpressed (recessive) allele for each gene. Autosomal inheritance is supported by studies in 26 families including 105 children for CON 1 and

Edwin A. Azen; Pao-Lo Yu

1984-01-01

123

The Pros & Cons of Environmental Debates.  

ERIC Educational Resources Information Center

The preparation and format of debates that deal with environmental issues are presented. The educational pros and cons of such debates are discussed. A list of 30 suggested environmental debate topics and a reproducible debate evaluation form are provided. (KR)

Zipko, Stephen J.

1991-01-01

124

Capire la volatilità con il modello binomiale  

Microsoft Academic Search

Questo lavoro si propone di illustrare i concetti basilari dell'arbitrage pricing degli strumenti finanziari derivati mediante semplici modelli a tempo discreto che non richiedono nozioni di calcolo differenziale. In particolare si analizzano le proprietà statistiche dei prezzi e dei ritorni finanziari (valore atteso, varianza, deviazione standard) con riferimento alle distribuzioni \\

Luca Erzegovesi

1999-01-01

125

InterCon Travel Health Case Study  

Microsoft Academic Search

InterCon provides services to health insurers of foreign tourists who travel to the United States and Canada. After experiencing high growth, the company confronts several operational challenges. As a responsive measure, management considers developing an IT system. The system must go through the formal capital investment evaluation process, which requires estimation of costs and benefits and uses the NPV method.

Michael A. Goldstein

2007-01-01

126

InterCon Travel Health: Case B  

ERIC Educational Resources Information Center

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…

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

2010-01-01

127

Google Scholar: the pros and the cons  

Microsoft Academic Search

Purpose – To identify the pros and the cons of Google Scholar. Design\\/methodology\\/approach – Chronicles the recent history of the Google Scholar search engine from its inception in November 2004 and critiques it with regard to its merits and demerits. Findings – Feels that there are massive content omissions presently but that, with future changes in its structure, Google Scholar

Péter Jacsó

2005-01-01

128

Aspectos relacionados con la sexualidad y la reproducción (PDQ®)  

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.

129

Aspectos relacionados con la sexualidad y la reproducción (PDQ®)  

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.

130

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

NASA Astrophysics Data System (ADS)

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.

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

2011-10-01

131

Energy Star program benefits Con Edison  

SciTech Connect

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.

NONE

1995-05-01

132

Web Spoofing: An Internet Con Game  

NSDL National Science Digital Library

The Safe Internet Programming group at the Princeton University Department of Computer Science in 1996 published a paper on the practice known as "web spoofing," through which an attacker intervenes between an end-user browsing the Web and real Web sites. The attacker sets up a shadow copy of the Web, and as users request pages from sites they will receive pages from the attacker's site instead. This process also enables attackers to gather data (possibly credit card numbers, etc.) submitted through bogus web forms. The nine-page paper describes how the con game works and suggests remedies. The article is available in PostScript, compressed PostScript, Microsoft Word, and zipped Microsoft Word format. Unfortunately, it is not available online as HTML.

Balfanz, Dirk ..; Dean, Drew.; Felten, Edward W.; Wallach, Dan S.

1996-01-01

133

Cervical disc arthroplasty: Pros and cons  

PubMed Central

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.

Moatz, Bradley; Tortolani, P. Justin

2012-01-01

134

Pros and cons of phage therapy  

PubMed Central

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.

Loc-Carrillo, Catherine

2011-01-01

135

Tratamiento cognitivo-conductual para niños mexicanos con fobia social  

Microsoft Academic Search

Participaron 17 niños, entre 7 y 12 años, con fobia social asignados aleatoriamente a 3 condiciones: (a) niños bajo el protocolo Intervención en Adolescentes con Fobia Social (IAFS; Olivares, 2005), (b) el mismo protocolo a los niños e información a sus padres sobre el trastorno, y (c) lista de espera. En evaluaciones de pretest, postest, 3 y 6 meses después,

Flor Gil-Bernal; Laura Hernández-Guzmán

2009-01-01

136

RoboCon: A general purpose telerobotic control center  

SciTech Connect

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.

Draper, J.V.; Noakes, M.W. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.; Schempf, H. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Blair, L.M. [Human Machine Interfaces, Inc., Knoxville, TN (United States)

1997-02-01

137

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...

138

Using the ConSAT: A Memo to Teachers.  

ERIC Educational Resources Information Center

Described is how teachers can use the Concept Structuring Analysis Technique (ConSAT) as a diagnostic, learning, and assessment task in teaching science. In essence, ConSAT assists students in organizing concepts on paper so that they may link what they already know to what they have to learn. The technique thus applies the philosophical notion of…

Champagne, Audrey B.; Klopfer, Leopold E.

139

Pro/con a precessional geodynamo  

NASA Astrophysics Data System (ADS)

The modest amount of research that exists on the ability, or lack of ability, of mantle precession to power a geodynamo developed mostly during the last half of the 1900s. Papers by Roberts and Stewartson (1965) and by Busse (1968) studied precession generally without a pro/con conclusion. Malkus in the late 1960s attempted to advance a positive role for precession through experiments and analysis. His experiments have survived criticism, but his analyses were discounted, especially by Rochester, Jacobs, Smylie, and Chong (1975) and by Loper (1975). Rochester, et al. critiqued existing analyses of precession, including those of Malkus, but did not reach a strong position either pro or con a precessional geodynamo. Loper argued emphatically that precession was not capable of powering the geodynamo. Explicit analyses that either critique or support Loper’s arguments have yet to appear in the literature. During the 1970s, Vanyo and associates studied energy dissipation during precession of satellite liquid fuels and its effect on satellite attitude stability. Engineers and scientists in every country that has launched satellites completed similar research. Some is published in the aerospace literature, more is available in company and government reports. Beginning in 1981, Vanyo and associates applied this knowledge to the very similar problem of energy dissipation and flow patterns in precessing mechanical models scaled geometrically and dynamically to the Earth’s liquid core. Energy experiments indicate massive amounts of mechanical energy are dissipated at the CMB, and flow experiments show complex motions within the boundary layer and axial flows with helicity throughout the interior. Analysis of Earth core precession also advanced, especially in several papers by Kerswell and by Tilgner in the late 1990s. Detail numerical models have yet to appear. Although progress in understanding the role of precession in Earth core motions has advanced, there remains a common belief, often expressed explicitly, that precession is incapable of energizing a geodynamo, a la Loper. We will present a critique of Loper’s 1975 paper and briefly discuss the common practice and belief that the geodynamo must be energized by thermal and/or compositional driven convection (motion). We note here that there is no observational evidence for existence of thermal or compositional convection within the liquid core or for growth of the solid core. Although there has been considerable success in adapting data in thermal/compositional models to yield near realistic solutions, that does not constitute a proof that those models apply to the Earth. There is absolute observational evidence for mantle precession, an Earth feature that is unique, along with the Earth’s magnetic field, among the terrestrial planets. We argue that great difficulty experienced in analysis and computation of precessional flow is a major explanation for its absence in current models of the geodynamo.

Vanyo, J.

2003-04-01

140

Crystal structure of a lectin from Canavalia maritima (ConM) in complex with trehalose and maltose reveals relevant mutation in ConA-like lectins  

Microsoft Academic Search

The crystal structure of Canavalia maritima lectin (ConM) complexed with trehalose and maltose revealed relevant point mutations in ConA-like lectins. ConM with the disaccharides and other ConA-like lectins complexed with carbohydrates demonstrated significant differences in the position of H-bonds. The main difference in the ConM structure is the replacement of Pro202 by Ser202, a residue that promotes the approximation of

Plínio Delatorre; Bruno A. M. Rocha; Carlos A. A. Gadelha; Tatiane Santi-Gadelha; João B. Cajazeiras; Emmanuel P. Souza; Kyria S. Nascimento; Valder N. Freire; Alexandre H. Sampaio; Walter F. Azevedo; Benildo S. Cavada

2006-01-01

141

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.

142

La gestione perioperatoria del paziente con insufficienza cardiaca cronica  

Microsoft Academic Search

\\u000a L’elevata morbidità e mortalità perioperatoria dei pazienti con insufficienza cardiaca cronica o CHF (chronic heart failure) potranno certamente essere ridotte nei prossimi anni migliorando le capacità diagnostiche degli anestesisti e dei chirurghi\\u000a e la qualità delle loro strategie di trattamento. (Precisiamo che in questo capitolo la sigla CHF viene usata con riferimento\\u000a alla tuttora accettata definizione di “Chronic Heart Failure”;

Biagio Allaria

143

ConChat: a context-aware chat program  

Microsoft Academic Search

ConChat is a context-aware chat program that enriches electronic communication by providing contextual information and resolving potential semantic conflicts between users.ConChat uses contextual information to improve electronic communication. Using contextual cues, users can infer during a conversation what the other person is doing and what is happening in his or her immediate surroundings. For example, if a user learns that

A. Ranganathan; R. H. Campbell; A. Ravi; A. Mahajan

2002-01-01

144

C31. EVALUACIÓN DE CUATRO GENOTIPOS DE MAÍZ AMARILLO (Zea mays L.) BAJO TRES NIVELES DE FERTILIZACIÓN DE NITRÓGENO Y FÓSFORO PARA LA PRODUCCIÓN DE \\  

Microsoft Academic Search

SUMMARY Ecuadorian food canning industry concerned for this provider's production, principally Baby Corn, has envisioned the necessity to find a new yellow corn genotype (Zea mays L.). Consequently, four genotypes of yellow corn were evaluated; Brasilia, SV1035, DK 5005 and INIAP 180, with three levels of nitrogen and phosphorous fertilization (0 kg\\/ha, 40 kg P2O5 con 16 kg nitrógeno y

145

Immunomodulatory effect of Tylophora indica on Con A induced lymphoproliferation.  

PubMed

Our preliminary studies with tylophora alkaloids had shown that they inhibit cellular immune responses like contact sensitivity to dinitro-flurobenzene and delayed hypersensitivity to sheep red blood cells, in vivo. Investigations were hence carried out to determine the cellular targets of tylophora alkaloids in in vitro systems. Con A induced proliferation of splenocytes was used as a model system to study the effect of the alkaloids on cellular immune responses. The alkaloid mixture was found to inhibit proliferation of splenocytes at higher concentrations and augment the same at lower concentrations. Both macrophages and T cells were found to be vulnerable to tylophora alkaloids. The alkaloid mixture suppressed IL-2 production in Con A stimulated splenocytes at the inhibitory or higher concentrations and enhanced production at the lower concentrations. IL-1 production by activated macrophages on the contrary was doubled in the presence of inhibitory concentrations of tylophora. These studies indicate that tylophora alkaloids have a concentration dependent biphasic effect on Con A induced mitogenesis. At lower concentrations they augment Con A induced lymphoproliferation by enhancing IL-2 production. Inhibition of proliferation at higher concentrations of the alkaloid is due to inhibition of IL-2 production and activation of macrophages, which have a cytostatic effect. PMID:11824517

Ganguly, T; Badheka, L P; Sainis, K B

2001-11-01

146

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.

147

Precisión de las velocidades radiales obtenidas con el REOSC  

NASA Astrophysics Data System (ADS)

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 ? =-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.

González, J. F.; Lapasset, E.

148

ConNexus to awarenex: extending awareness to mobile users  

Microsoft Academic Search

We explored the use of awareness information to facilitate communication by developing a series of prototypes. The ConNexus prototype integrates awareness information, instant messaging, and other communication channels in an interface that runs on a desktop computer. The Awarenex prototype extends that functionality to wireless handheld devices, such as a Palm. A speech interface also enables callers to make use

John C. Tang; Nicole Yankelovich; James Begole; Max Van Kleek; Francis C. Li; Janak R. Bhalodia

2001-01-01

149

Inclusion: The Pros and Cons--A Critical Review  

ERIC Educational Resources Information Center

The purpose of this paper was to review, analyze, and critique the pros and cons, the advantages and disadvantages, of inclusion. The methodology consisted in analyzing and comparing research findings on the benefits and costs of inclusion. Federal legislation and regulations on inclusion were examined, analyzed, and discussed. The results showed…

Savich, Carl

2008-01-01

150

LunGradCon: The Lunar Graduate Conference  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

151

Runtime Verification for Generic Classes with ConGu 2  

NASA Astrophysics Data System (ADS)

Even though generics became quite popular in mainstream object-oriented (OO) languages, approaches for checking at runtime the conformance of such programs against formal specifications still lack appropriate support. In order to overcome this limitation within ConGu, a tool-based approach we have been developing to support runtime conformance checking of Java programs against algebraic specifications, we recently proposed a notion of refinement mapping that allows to define correspondences between parametric specifications and generic classes. Based on such mappings, we also put forward a notion of conformance between the two concepts. In this paper we present how the new notion of conformance is supported by version 2 of the ConGu tool.

Crispim, Pedro; Lopes, Antónia; Vasconcelos, Vasco T.

152

The Pros and Cons of RFID in Supply Chain Management  

Microsoft Academic Search

This paper presents the pros and cons of using Radio-Frequency IDentification (RFID) in Supply Chain Management (SCM). While RFID has a greater number of benefits than its predecessor, the bar code, it currently comes at a price that many businesses still consider prohibitive. On the one hand, RFID is advantageous because it does not require line-of-sight scanning, it acts to

Katina Michael; Luke Mccathie

2005-01-01

153

Métodos con información genética para abordar la complejidad del cáncer de pulmón  

Cancer.gov

Se estima que 220 000 personas recibieron un diagnóstico de alguna forma de cáncer de pulmón en 2010. Es la principal causa de muertes relacionadas con el cáncer, con más de 157 000 muertes previstas en 2010.

154

Effect of different fixatives on Con A surface receptors of mouse peritoneal macrophages  

Microsoft Academic Search

The effects of glutaraldehyde, formaldehyde, or osmium tetroxide fixation on the number of labeled Con A surface receptors on mouse peritoneal macrophages were compared. Gold-labeled Con A receptors were found to be isolatedly arranged and evenly distributed on cell surfaces independent of the fixative used. Only cells preincubated with Con A and subsequently fixed by osmium tetroxide showed arrangement of

Th. Peschke; L. Wollweber; A. Gabert; K. Augsten; R. Stracke

1990-01-01

155

Probabilidad de colisión de cometas periódicos con partículas interplanetarias  

NASA Astrophysics Data System (ADS)

Se presentan resultados sobre la probabilidad de colisión de cometas de corto período con la población de partículas interplanetarias presentes en la región del cinturón de asteroides. Se encuentra que este proceso colisional afecta la evolución física de los cometas de manera no despreciable y puede ser el responsable de variaciones de brillo de tipo ``outburst". Se presentan resultados para algunos cometas en particular y se obtiene un límite inferior para el tamaño de los núcleos en función de la distribución de radios del cinturón de asteroides.

Gil Hutton, R.

156

Molecular diagnostics: Molecular Med Tri-Con 2013.  

PubMed

The 20th annual Molecular Med Tri-Con conference, sponsored by Cambridge Health Institute (MA, USA), consisted of over 250 presentations within five parallel 'channels': 'Diagnostics, Therapeutics, Clinical, Informatics and Cancer', along with five preliminary symposia, 15 short courses, a plenary keynote session entitled 'Personalized Oncology - Fulfilling the Promise for Today's Patients' and a keynote panel entitled, 'Emerging Technologies and Industry Perspectives'. Over 3000 individuals from academia, clinical laboratories and industry were in attendance. This article will focus on the Keynote Session of 'Molecular Diagnostics' track within the Diagnostics Channel. PMID:23895123

Klein, Roger D

2013-07-01

157

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

PubMed

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

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

2014-07-01

158

RoboCon: Operator interface for robotic applications  

SciTech Connect

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.

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

1996-12-31

159

IMPACT: integrated multiprogram platform for analyses in ConTest.  

PubMed

In this paper, we introduce a new Graphical User Interface that estimates evolutionary rates on protein sequences by assessing changes in biochemical constraints. We describe IMPACT, a platform-independent (tested in Linux, Windows, and MacOS), easy to install software written in Java. IMPACT integrates the use of a built-in multiple sequence alignment editor, with programs that perform phylogenetic and protein structure analyses (ConTest, PhyML, ATV, and Jmol) allowing the user to quickly and efficiently perform evolutionary analyses on protein sequences, including the detection of selection (negative and positive) signatures at the amino acid scale, which can provide fundamental insight about species evolution and ecological fitness. IMPACT provides the user with a working platform that combines a number of bioinformatics tools and utilities in one place, transferring information directly among the various programs and therefore increasing the overall performance of evolutionary analyses on proteins. PMID:21414966

Maldonado, Emanuel; Dutheil, Julien Y; da Fonseca, Rute R; Vasconcelos, Vítor; Antunes, Agostinho

2011-01-01

160

Pros, cons, and costs of INFUSE in spinal surgery  

PubMed Central

Background: INFUSE (recombinant human bone morphogenetic protein-2 [rh-BMP-2]; Medtronic, Memphis, TN, USA) is approved by the Federal Drug Administration (FDA) only for use with the lumbar tapered fusion device (LT Cage; Medtronic) to perform single-level anterior lumbar interbody fusions (ALIF: L2-S1 levels). INFUSE, however, is widely utilized in an “off-label” capacity for anterior and/or posterior cervical, thoracic, and lumbar surgery. Nevertheless, Medicare and other insurance companies, are now increasingly denying reimbursement (average cost of a “large” INFUSE to the hospital without overhead $5000-6000) to hospitals for INFUSE when utilized “off-label”. Methods: This commentary looks at several representative studies citing the cons associated with utilizing INFUSE in spinal surgery, contraindications, complications, and cost factors. Results: There are multiple cons of utilizing INFUSE in an “off-label” capacity for spinal surgery. Direct contraindications include pregnancy, allergy to titanium, allergy to bovine type I collagen or rhBMP-2, infection, tumor, liver or kidney disease, immunosuppression (e.g., lupus, HIV/AIDS); contraindications are also seen in those receiving radiation, chemotherapy, or steroids. Reported complications include exuberant/ectopic bone formation, paralysis (cord, nerve damage), dural tears, bowel–bladder and sexual dysfunction, respiratory failure, inflammation of adjacent tissues, fetal developmental complications, scar, excessive bleeding, and even death. Complications are so prevalent in the anterior cervical spine, that many surgeons no longer use it in this region. Similarly, INFUSE complications and indications for posterior lumbar interbody fusions (PLIFs) and transforaminal interbody lumbar fusions (TLIFs) should also be reexamined. Conclusions: More surgeons need to question the safety, efficacy, and appropriate “off-label” use of INFUSE in all spine surgeries.

Epstein, Nancy E.

2011-01-01

161

Con A conjugated to Europium(III) cryptate as a new histological tool for prostate cancer investigation using confocal microscopy.  

PubMed

Abstract Lectins are carbohydrate recognition proteins that can be used as probes to reveal the glycosylation state of cells. They frequently have been used for diagnostic and prognostic cancer studies. For fluorescence based analysis, lectins commonly are conjugated to fluorescein isothiocyanate (Con A-FITC); however, this molecule loses its fluorescence quickly. We conjugated Europium cryptate to Con A (Con A-cryp-Eu) for use as a histochemical luminescent probe to recognize glucose/mannose residues in benign prostatic hyperplasia and prostatic carcinoma tissues, and used confocal microscopy instead of commercial Con A-FITC. Tissues were treated with Evans blue to suppress intrinsic tissue fluorescence before incubation with Con A-cryp-Eu or Con A-FITC. Con A-cryp-Eu exhibited hemagglutinating activity. Con A-cryp-Eu showed the same binding pattern as Con A-FITC in prostate stroma and gland cells. Staining was strong in benign prostate hyperplasia and prostate carcinoma tissues. Con A-cryp-Eu probe stained glucose/mannose residues in prostatic carcinoma more intensely than Con A-FITC. Furthermore, staining with Con A-cryp-Eu showed greater fluorescence intensity than Con A-FITC and the emission of Con A-cryp-Eu was more stable than the Con A-FITC for seven days under the same storage conditions. Maintenance of the luminescent properties and the binding pattern of Con A-cryp-Eu favor its use as an auxiliary histochemistry probe for prostatic tissue studies. PMID:24160413

Rêgo, Mjbm; Silva, Lpbg; Medeiros, Jkg; Figueiredo, Rcbq; Alves-Júnior, S; Beltrão, Eic

2014-07-01

162

Development of new series of aluminium solid capacitors with organic semiconductive electrolyte (OS-CON)  

NASA Astrophysics Data System (ADS)

We have researched tetrecyanoquinodimethane (TCNQ) complex salts, developed a new series of organic semiconductive electrolytes (OS-CONs) such as chip-type OS-CONs, and improved our original facilities for mass-production of OS-CONs during the ten years since mass-production was begun. Results of this research and development are presented in this paper. Various new applications of OS-CONs have been developed which fully utilize their properties. This paper also introduces some of these new applications.

Niwa, Shinichi; Taketani, Yutaka

163

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

Microsoft Academic Search

Background This was the second year that our breath colleagues organized a networking session at the Pittsburgh Conference and Exposition, or 'PittCon' (www.pittcon.org\\/). This time it was called 'Non Invasive Biomedical Analysis' to broaden the scope a bit, but the primary focus remained on exhaled breath diagnostics. As reported last year in the Journal of Breath Research, PittCon continues to

Joachim D. Pleil

2011-01-01

164

Immune cascades in human intervertebral disc: the pros and cons  

PubMed Central

The unique structural hallmark of the intervertebral disc has made its central composition, the nucleus pulposus (NP), excluded from the immunologic tolerance. Consequently, the intervertebral disc is identified as an immune-privileged organ. Traditionally, local detrimental immune activities caused by NP at the lesion sites of the disc are noted as a significant factor contributing to disc degeneration. However, given the beneficial activities of immune cells in other immune-privileged sites on basis of current evidence, the degenerate disc might need the assistance of a subpopulation of immune cells to restore its structure and lessen inflammation. In addition, the beneficial impact of immune cells can be seen in the absorption of the herniated NP, which is an important factor causes the mechanical compression of nerve roots. Consequently, a modulated immune network in degenerate disc is essential for the restoration of this immune-privileged organ. Until now, the understandings of immune response in disc degeneration still rest on the harmful aspect. Further studies are needed to explore its beneficial influence. Accordingly, there are no absolutely the pros and cons in terms of immune reactions caused by NP.

Sun, Zhen; Zhang, Ming; Zhao, Xu-Hong; Liu, Zhi-Heng; Gao, Yang; Samartzis, Dino; Wang, Hai-Qiang; Luo, Zhuo-Jing

2013-01-01

165

Pros, Cons, and Alternatives to Weight Based Cost Estimating  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

166

A National Look at Postmodernism's Pros and Cons in Educational Leadership  

ERIC Educational Resources Information Center

The purpose of this article is to take a look at the pros and cons of postmodernism. It is imperative for administrators to closely examine educational theories and practices prior to instituting changes. The ability to read and digest challenging material keeps one informed and prepared to lead effectively. This paper will list the pros and cons

Townsell, Rhodena

2007-01-01

167

La salud en personas con discapacidad intelectual en Espa?a: estudio europeo POMONA-II  

PubMed Central

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.

Martinez-Leal, Rafael; Salvador-Carulla, Luis; Gutierrez-Colosia, Mencia Ruiz; Nadal, Margarida; Novell-Alsina, Ramon; Martorell, Almudena; Gonzalez-Gordon, Rodrigo G.; Merida-Gutierrez, M. Reyes; Angel, Silvia; Milagrosa-Tejonero, Luisa; Rodriguez, Alicia; Garcia-Gutierrez, Juan C.; Perez-Vicente, Amado; Garcia-Ibanez, Jose; Aguilera-Ines, Francisco

2011-01-01

168

Resistencia a la flexión de vigas laminadas con tres especies de madera tropical mexicana  

Microsoft Academic Search

La madera aserrada tiene un comportamiento estructural adecuado; sin embargo, hay factores que influyen negativamente en su uso; tales como, los defectos anatómicos, la escasez de piezas grandes y la extracción de volúmenes insuficientes. Para subsanar estas limitaciones, se puede considerar como alternativa la fabricación de vigas laminadas, las cuales se forman con láminas de madera pegadas con algún tipo

Artículo de Investigación; Omar Araujo Molina; Miguel Cerón Cardeña; Mario Chan Martín; Manuel Azueta García

2005-01-01

169

Antibiotic susceptibility of coagulase-negative staphylococci (CoNS): emergence of teicoplanin-non-susceptible CoNS strains with inducible resistance to vancomycin.  

PubMed

Coagulase-negative staphylococci (CoNS) have become increasingly recognized as important agents of nosocomial infection. One of the characteristics of CoNS is their resistance to multiple antimicrobial agents commonly used for the treatment of staphylococcal infections. CoNS strains (n?=?745) isolated from a university teaching hospital in China between 2004 and 2009 were tested for antibiotic resistance. The antibiotics were placed into three categories based on resistance levels of the CoNS strains to these antibiotics: high resistance (resistance rate >70?%), including penicillin G, oxacillin and erythromycin; medium resistance (resistance rate between 30 and 70?%), including tetracycline, clindamycin, ciprofloxacin, trimethoprim/sulfamethoxazole and chloramphenicol; and low resistance (resistance rate <30?%), including rifampicin, ceftizoxime and gentamicin. We also found that the prevalence of strains non-susceptible to teicoplanin increased from 4.5 to 6.7?% between 2008 and 2009. A one-step vancomycin agar selection experiment and subsequent population analysis revealed potentially vancomycin-resistant subpopulations that have been selected from the teicoplanin-non-susceptible strains. Vigilant surveillance of nosocomial isolates of CoNS is needed to determine their resistance to glycopeptides. PMID:21799199

Ma, Xiao Xue; Wang, En Hua; Liu, Yong; Luo, En Jie

2011-11-01

170

Bioquimioterapia ambulatoria con cisplatino, dacarbacina, interleucina-2 e interferón-alfa en pacientes con melanoma avanzado. Estudio multicéntrico en 44 pacientes  

Microsoft Academic Search

Resumen\\u000a Fundamento  Se ha descrito una importante actividad (50% de respuestas objetivas) con un pequeño número de supervivientes en los ensayos\\u000a clínicos de quimioinmunoterapia (QIT) para el melanoma diseminado. En la mayoría, la hospitalización era un requerimiento\\u000a habitual.\\u000a \\u000a \\u000a \\u000a Objetivos  Valorar la posibilidad de administración ambulatoria completa de la QIT dentro de un ensayo fase II multicéntrico con cisplatino+dacarbacina\\u000a (DTIC) en un día,

Elena Filipovich Vegas; José Ignacio Mayordomo Cámara; José Anadrés Meana García; Manuel Valladares Ayerbes; Jesús Florián Jericó; Juan José Bretón García; Remedios Blanco Guerrero; Dolores Isla Casado; Carmen Santander Lobera; Raquel Andrés Conejero; Bartolomeu Massuti Sureda; Alejandro Tres Sánchez

2003-01-01

171

Mapping the (Con)textual Plight of Man: The Temporal and Spatial Logics of Postmodem Masculinity  

Microsoft Academic Search

My thesis, Mapping the (Con)textual Plight of Man: The Temporal and Spatial Logics of Post modern Masculinity brings together a number of Marxist and Post-Structuralist theorists in order to make sense of the notion of \\

Jason Demers

2003-01-01

172

Análisis del espectro infrarrojo del polvo interestelar asociado con cúmulos globulares y de su evolución temporal  

NASA Astrophysics Data System (ADS)

El trabajo que se presenta investiga la dinámica de las partículas de polvo interestelar eyectadas por estrellas gigantes rojas en un cúmulo globular utilizando simulaciones numéricas de su interacción con el campo gravitatorio y con la radiación electromagnética de las estrellas. Se pretende con ello determinar la distribución espacial de ese material como una función del tiempo en un sistema similar a NGC 104 (47 Tuc). A partir de la distribución espacial resultante se obtuvo el espectro infrarrojo integrado el cual sugiere que el máximo contraste con la radiación estelar ocurre en longitudes de onda cercanas a 300 ?m y que decrece rápidamente hacia longitudes de onda menores, en las que suelen realizarse las observaciones.

Pellizza, L. J.; Forte, J. C.; Carpintero, D.

173

40 CFR 63.621 - Definitions.  

Code of Federal Regulations, 2013 CFR

...Equivalent P 2 O5 feed means the quantity of phosphorus, expressed as phosphorous pentoxide, fed to...P 2 O5 stored means the quantity of phosphorus, expressed as phosphorus pentoxide, being cured or stored in the...

2013-07-01

174

METODI PER LA VALUTAZIONE DEGLI AIUTI ALLE IMPRESE CON SPECIFICO TARGET TERRITORIALE  

Microsoft Academic Search

La valutazione d'impatto dei programmi di aiuto alle imprese con specifico target territoriale è un tema che ha interessato recenti sviluppi metodologici della letteratura statistico-economica internazionale e che ha registrato un crescente interesse anche in ambito italiano. L'assenza di dati di natura sperimentale per questo tipo di interventi espone al rischio di distorsione le stime d'impatto ottenibili con ciascuna delle

Daniele Bondonio

175

Análisis comparativo de 3 regímenes de tratamiento en niños con linfoma de Burkitt  

Microsoft Academic Search

Resumen  De enero de 1980 a junio de 1996 se trataron en nuestra institución un total de 86 pacientes con linfoma de Burkitt. El presente\\u000a estudio es una revisión retrospectiva en el que se comparan las complicaciones y los resultados de sobrevida utilizando 3\\u000a esquemas de tratamiento distintos.\\u000a \\u000a Se trataron 46 pacientes en el régimen 1, 26 con el régimen 2,

Rocío Cárdenas Cardós; Roberto Rivera Luna; Roxana Martínez Agreda; Carlos Calderón Elvir; Amparo Plata García

2001-01-01

176

Quimioterapia de alta dosis prolonga en forma significativa la supervivencia en pacientes con leucemia mieloide aguda  

Cancer.gov

Los resultados preliminares de un estudio clínico grande con asignación al azar de pacientes de 16 a 60 años de edad con leucemia mieloide aguda (LMA), un cáncer de la sangre y de la médula ósea, que no había sido tratada anteriormente, muestran que los pacientes que recibieron una alta dosis de daunorrubicina, un fármaco de quimioterapia disponible comercialmente, durante la terapia inicial vivieron más que los pacientes que recibieron una dosis normal del mismo fármaco.

177

Navegaçao conceitual em ambientes de gestao do conhecimento usando NavCon  

Microsoft Academic Search

This article presents conceptual navigation and NavCon, an architecture that implements this navigation in World-Wide Web pages. NavCon architecture makes use of ontology as metadata to contextualize user's search for information. Conceptual navigation is a technique to browse Web sites within a context. Context filters relevant retrieved information. Context also drives user's navigation through paths that meet his needs. Based

José Renato V. Dantas; Pedro Porfírio M. Farias

2008-01-01

178

Pros and cons: prospective predictors of marijuana use on a college campus.  

PubMed

Marijuana use on college campuses is prevalent and associated with high rates of abuse and dependence. The Marijuana Decisional Balance (MDB) scales measure perceived pros and cons toward marijuana use. Evidence supports reliability and concurrent validity of these scales, but the predictive validity has not yet been assessed. The current study evaluated the prospective predictive validity of pros and cons scales for marijuana use, as well as explored predictive validity for marijuana problem indicators. Secondary analyses included test-retest reliability and internal consistency, to provide additional evidence of psychometric properties. A total of 149 college students (57% recent marijuana users, 77% lifetime users) participated in a baseline survey, then completed a second survey one month later. All provided data on marijuana pros and cons, as well as use status in the past month. Users at each time point reported on use frequency, problems, and disorder symptoms. In the month between assessments, 55% of the students used marijuana. Both pros and cons subscales prospectively predicted use status in the subsequent month, but not use frequency. Pros prospectively predicted marijuana problems and dependence symptoms at follow-up, and remained a significant predictor of later dependence symptoms even after controlling for baseline dependence symptoms. In contrast, pros only marginally predicted abuse. Cons did not predict problems, abuse, or dependence symptoms. Pros and cons showed strong test-retest reliability (rs = 0.80-0.85) and internal consistency (alphas = 0.92-0.95). In a college sample, pros and cons of marijuana use demonstrated stability over one month, and prospectively predicted use. Pros may also have utility in predicting problems and dependence potential on college campuses. PMID:22985053

Elliott, Jennifer C; Carey, Kate B

2013-03-01

179

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

PubMed

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

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

180

Virulence, Speciation and Antibiotic Susceptibility of Ocular Coagualase Negative Staphylococci (CoNS)  

PubMed Central

Background: Coagulase negative Staphylococci (CoNS) are common inhabitants of human skin and mucous membranes. With the emergence of these organisms as prominent pathogens in patients with ocular infections, investigation has intensified in an effort to identify important virulence factors and to inform new approaches to treatment and prevention. Aim: To isolate CoNS from ocular specimens; to study the possible virulence factors; speciation of coagulase negative staphylococci (CoNS) which were isolated from ocular complications; antibiotic susceptibility testing of ocular CoNS. Materials and Methods: The specimens were collected from the target patients who attended the Microbiology Laboratory of a tertiary care eye hospital in Coimbatore, Tamilnadu state, India. The isolates were subjected to tube and slide coagulase tests for the identification of CoNS. All the isolates were subjected to screening for lipase and protease activities. Screening for other virulence factors viz., slime production on Congo red agar medium and haemagglutination assay with use of 96-well microtitre plates. These isolates were identified upto species level by performing biochemical tests such as phosphatase test, arginine test, maltose and trehalose fermentation tests and novobiocin sensitivity test. The isolates were subjected to antibiotic susceptibility studies, based on the revised standards of Clinical and Laboratory Standards Institutes (CLSI). Results: During the one year of study, among the total 260 individuals who were screened, 100 isolates of CoNS were obtained. Lipolytic activity was seen in all the isolates, whereas 38 isolates showed a positive result for protease. A total of 63 isolates showed slime production. Of 100 isolates, 30 isolates were analyzed for haemagglutination, where 4 isolates showed the capacity to agglutinate the erythrocytes. The results of the biochemical analysis revealed that of the 100 isolates of CoNS, 43% were Staphylococcus epidermidis. The other isolates were identified as S. xylosus (n=8), S. captis (n=16), S. haemolyticus (n=10), S. saccharolyticus (n=2), S. hominis (n=5), S. saprophyticus (n=6) and S. intermedius (n=1). On the other hand, 9 isolates were not identified. In the antibiotic susceptibility analysis, it was found that most of the isolates were sensitive to vancomycin, amikacin and linczolid and resistant to cefatoxime, oxacillin, bacitracin and nalidixic acid. Conclusion: S. epidermidis was found to be predominant in causing the ocular complications. Slime production, heamagglutination, protease and lipase activities could be the putative virulence factors of CoNS. Antibiotic susceptibility patterns of CoNS against antibacterial agents revealed maximum resistance to beta lactam groups, and the resistance was found to be higher to oxacillin, and lowest to vancomycin.

Priya, Ravindran; Mythili, Arumugam; Singh, Yendremban Randhir Babu; Sreekumar, Haridas; Manikandan, Palanisamy; Panneerselvam, Kanesan

2014-01-01

181

Virulence, Speciation and Antibiotic Susceptibility of Ocular Coagualase Negative Staphylococci (CoNS).  

PubMed

Background: Coagulase negative Staphylococci (CoNS) are common inhabitants of human skin and mucous membranes. With the emergence of these organisms as prominent pathogens in patients with ocular infections, investigation has intensified in an effort to identify important virulence factors and to inform new approaches to treatment and prevention. Aim: To isolate CoNS from ocular specimens; to study the possible virulence factors; speciation of coagulase negative staphylococci (CoNS) which were isolated from ocular complications; antibiotic susceptibility testing of ocular CoNS. Materials and Methods: The specimens were collected from the target patients who attended the Microbiology Laboratory of a tertiary care eye hospital in Coimbatore, Tamilnadu state, India. The isolates were subjected to tube and slide coagulase tests for the identification of CoNS. All the isolates were subjected to screening for lipase and protease activities. Screening for other virulence factors viz., slime production on Congo red agar medium and haemagglutination assay with use of 96-well microtitre plates. These isolates were identified upto species level by performing biochemical tests such as phosphatase test, arginine test, maltose and trehalose fermentation tests and novobiocin sensitivity test. The isolates were subjected to antibiotic susceptibility studies, based on the revised standards of Clinical and Laboratory Standards Institutes (CLSI). Results: During the one year of study, among the total 260 individuals who were screened, 100 isolates of CoNS were obtained. Lipolytic activity was seen in all the isolates, whereas 38 isolates showed a positive result for protease. A total of 63 isolates showed slime production. Of 100 isolates, 30 isolates were analyzed for haemagglutination, where 4 isolates showed the capacity to agglutinate the erythrocytes. The results of the biochemical analysis revealed that of the 100 isolates of CoNS, 43% were Staphylococcus epidermidis. The other isolates were identified as S. xylosus (n=8), S. captis (n=16), S. haemolyticus (n=10), S. saccharolyticus (n=2), S. hominis (n=5), S. saprophyticus (n=6) and S. intermedius (n=1). On the other hand, 9 isolates were not identified. In the antibiotic susceptibility analysis, it was found that most of the isolates were sensitive to vancomycin, amikacin and linczolid and resistant to cefatoxime, oxacillin, bacitracin and nalidixic acid. Conclusion: S. epidermidis was found to be predominant in causing the ocular complications. Slime production, heamagglutination, protease and lipase activities could be the putative virulence factors of CoNS. Antibiotic susceptibility patterns of CoNS against antibacterial agents revealed maximum resistance to beta lactam groups, and the resistance was found to be higher to oxacillin, and lowest to vancomycin. PMID:24995181

Priya, Ravindran; Mythili, Arumugam; Singh, Yendremban Randhir Babu; Sreekumar, Haridas; Manikandan, Palanisamy; Panneerselvam, Kanesan; Shobana, Coimbatore Subramanian

2014-05-01

182

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

183

ConSole: using modularity of Contact maps to locate Solenoid domains in protein structures  

PubMed Central

Background Periodic proteins, characterized by the presence of multiple repeats of short motifs, form an interesting and seldom-studied group. Due to often extreme divergence in sequence, detection and analysis of such motifs is performed more reliably on the structural level. Yet, few algorithms have been developed for the detection and analysis of structures of periodic proteins. Results ConSole recognizes modularity in protein contact maps, allowing for precise identification of repeats in solenoid protein structures, an important subgroup of periodic proteins. Tests on benchmarks show that ConSole has higher recognition accuracy as compared to Raphael, the only other publicly available solenoid structure detection tool. As a next step of ConSole analysis, we show how detection of solenoid repeats in structures can be used to improve sequence recognition of these motifs and to detect subtle irregularities of repeat lengths in three solenoid protein families. Conclusions The ConSole algorithm provides a fast and accurate tool to recognize solenoid protein structures as a whole and to identify individual solenoid repeat units from a structure. ConSole is available as a web-based, interactive server and is available for download at http://console.sanfordburnham.org.

2014-01-01

184

Observations on the use of GonaCon in captive female elk (Cervus elaphus).  

PubMed

Overabundant populations of elk (Cervus elaphus) are a significant concern in some areas of the western United States because of potential ecologic damage and spread of brucellosis to domestic livestock. Brucella abortus is transmitted among elk through direct contact with aborted fetuses, placentas and associated fluids, or postpartum discharge of infected animals. Because transmission of brucellosis is dependent on pregnancy, contraception of cows could be used for both disease and population management. The objective of this study was to evaluate the contraceptive efficacy of a gonadotropin-releasing hormone vaccine (GonaCon) in female elk. In September 2004, cows were given a single immunization of either 1,000 microg (n = 12) or 2,000 microg (n = 10) of GonaCon and compared with a group of adjuvant-treated controls (n = 15). In November 2004, 2005, and 2006, cows were grouped with bulls for the breeding season. Blood samples were taken in February 2005 and March 2006 and 2007 for pregnancy testing, progesterone assays, and antibody titers. For cows given 1,000 microg GonaCon the percentages that were infertile for 2005, 2006, and 2007 were 86%, 90%, and 100%, respectively, compared with 90%, 100%, and 100% for cows given 2,000 microg GonaCon. Rates of infertility for control cows were 23%, 28%, and 0% (P<0.0001). The results indicated that either dose of GonaCon prevented pregnancy of elk cows for at least 3 yr. We concluded that GonaCon use for population management of elk warrants consideration as part of a strategy to control brucellosis. PMID:19204347

Killian, Gary; Kreeger, Terry J; Rhyan, Jack; Fagerstone, Kathleen; Miller, Lowell

2009-01-01

185

GeConT 2: gene context analysis for orthologous proteins, conserved domains and metabolic pathways  

PubMed Central

The Gene Context Tool (GeConT) allows users to visualize the genomic context of a gene or a group of genes and their orthologous relationships within fully sequenced bacterial genomes. The new version of the server incorporates information from the COG, Pfam and KEGG databases, allowing users to have an integrated graphical representation of the function of genes at multiple levels, their phylogenetic distribution and their genomic context. The sequence of any of the genes can be easily retrieved, as well as the 5? or 3? regulatory regions, greatly facilitating further types of analysis. GeConT 2 is available at: http://bioinfo.ibt.unam.mx/gecont.

Martinez-Guerrero, C. E.; Ciria, R.; Abreu-Goodger, C.; Moreno-Hagelsieb, G.; Merino, E.

2008-01-01

186

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

Microsoft Academic Search

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.

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

2009-01-01

187

Cost-of-Living Adjustments in Teacher Contracts: Pros and Cons. ERS Information Aid.  

ERIC Educational Resources Information Center

This publication summarizes the history of cost-of-living (COL) adjustment clauses in salary contracts in private industry and the teaching profession, and then discusses the pros and cons of including COL clauses in teacher contracts. The merits of COL clauses are examined from the viewpoints of both employees and employers. Included are a number…

Sullivan, Joan P.

188

Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas  

Microsoft Academic Search

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.

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

2003-01-01

189

Violación del Principio de Equivalencia en Teorías con Dilatón de Cuerdas  

NASA Astrophysics Data System (ADS)

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.

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

190

A Qualitative Approach to Upward Evaluation of Leadership Performance: Pros and Cons  

ERIC Educational Resources Information Center

This article describes a qualitative upward evaluation of the leadership performance of library managers. Follow-up studies were conducted, focusing on the advantages and disadvantages of the qualitative approach to upward appraisal. The authors discuss pros and cons to guide others who might use this methodology for upward appraisals in the…

Turrentine, Cathryn G.; Lener, Edward F.; Young, Michelle L.; Kok, Victoria T.

2004-01-01

191

An Alternative Hemostatic Dressing: Comparison of CELOX, HemCon, and  

Microsoft Academic Search

Objectives: Uncontrolled hemorrhage remains a leading cause of traumatic death. Several topical adjunct agents have been shown to be effective in controlling hemorrhage, and two, chitosan wafer dressing (HemCon (HC)) and zeolite powder dressing (QuikClot (QC)), are being utilized regularly on the battlefield. However, recent literature reviews have concluded that no ideal topical agent exists. The authors compared a new

Buddy G. Kozen; Sara J. Kircher; Jose Henao; Fermin S. Godinez; Andrew S. Johnson

192

Outsource or in-house facilities management: The pros and cons  

Microsoft Academic Search

The question of the merits of outsourcing facilities management remains relevant. This paper attempts to determine a clear distinction between out tasking and outsourcing, and then to provide a model to explain the advantages (pros) and disadvantages (cons) of this strategy by analysing the wants of both the client and supplier. Finally, it offers some guidance to assist with remedying

Neil Usher

2004-01-01

193

El cáncer según su ubicación en el cuerpo: Relacionado con el sida  

Cancer.gov

In English En español In English En español El cáncer según su ubicación en el cuerpo: Relacionado con el sida Para buscar un tipo de cáncer, seleccione su ubicación en el cuerpo — Aparato locomotor Aparato respiratorio y tórax Cabeza y cuello

194

DISEÑO E IMPLEMENTACIÓN ÓPTIMA DE PERIFÉRICOS DE DSP CON SYSTEM GENERATOR PARA MICROBLAZE  

Microsoft Academic Search

Con este trabajo pretendemos analizar como se lleva a cabo el diseño de periféricos de DSP utilizando uno de los nuevos entornos de diseño de alto nivel: System Generator for DSP. Así, en este documento el objetivo es mostrar por un lado las características del entorno de diseño y las herramientas utilizadas y por otro la metodología de diseño e

J. Viejo; E. Ostua; M. J. Bellido; J. Juan; A. Millan; P. Ruiz-de-Clavijo; D. Guerrero

195

Immunostimulatory activity of ConBr: a focus on splenocyte proliferation and proliferative cytokine secretion.  

PubMed

Lectins constitute a class of glycoproteins, which are capable of selectively and reversibly binding to carbohydrates, distinguishing small structural differences in complex oligosaccharides. Studies have shown that the binding of lectins to cell-surface carbohydrates can lead to various effects such as cellular proliferation, histamine release and cytokine production. Canavalia brasiliensis lectin (ConBr) is a (D-mannose) D-glucose lectin. In this study, murine splenocytes were cultured to determine the effect of ConBr on cell proliferation, nitric oxide (NO) release and cytokine secretion. In addition, cellular viability assays were performed to evaluate any mitogenic activity induced by this lectin. ConBr significantly increased cell proliferation with minimal cell damage. This lectin was able to induce an increased production of cytokines such as IL-2, IL-6 and IFN-? and a decreased production of IL- 10. The release of NO was also observed. The results of this study indicate that ConBr could potentially be used as an immunomodulator. PMID:22009293

de Oliveira Silva, Flávio; das Neves Santos, Priscila; de Melo, Cristiane Moutinho Lagos; Teixeira, Edson Holanda; de Sousa Cavada, Benildo; Arruda, Francisco Vassiliepe Sousa; Cajazeiras, João Batista; Almeida, Alysson Chaves; Pereira, Valéria Alves Rêgo; Porto, Ana Lúcia Figueiredo

2011-11-01

196

SISTEMA REMOTO DE ADQUISICIÓN PARA EL CONTROL DEL RUIDO AMBIENTAL CON FPGA Y FPAA  

Microsoft Academic Search

RESUMEN Este artículo propone el diseño de un sistema de adquisición de datos con componentes digitales y analógicos microelectrónicos reconfigurables, como son el FPGA (Field Programmable Gate Array) y el FPAA (Field Programmable Analog Array), para monitorear y analizar la contaminación por ruido ambiental. Este prototipo obtiene los datos del ruido de una zona vial (zona centro de una ciudad)

A. Castillo Atoche; J. Vázquez Castillo; V. Sanchez Huerta; P. Del Río Dawn

197

Somatic Chromosomes of Eight Mammals from Con Son Island, South Vietnam.  

National Technical Information Service (NTIS)

Somatic chromosomes of mammals from Con Son Island, Republic of (South) Vietnam were: Suncus murinus murinus, 2n=40; Tupaia glis dissimilis, 2n=60; Macaca fascicularis condorensis, 2n=42; Rattus berdmorei magnus, 2n=40; R. exulans subsp., 2n=42; R. nivive...

J. F. Duncan P. F. D. Van Peenen P. F. Ryan

1969-01-01

198

ANALISI SPERIMENTALE DEL CONTATTO PIANO-PIANO CON INDENTATORE CILINDRICO RACCORDATO  

Microsoft Academic Search

Sommario Nel presente studio è proposta l'analisi sperimentale, mediante ultrasuoni, del contatto tra un indentatore cilindrico piano a bordi raccordati ed un piano, problema per il quale è stata recentemente proposta una soluzione analitica mai validata sperimentalmente. Per ciascun accoppiamento è stata valutata la riflessione dall'interfaccia, che è noto essere in relazione con lo stato di contatto. I risultati sperimentali

B. Leban; M. Pau; A. Baldi; F. Ginesu

199

Electronic structure and reactivity of the CNO/NCO/CON isomers  

NASA Astrophysics Data System (ADS)

Three-dimensional potential energy surfaces (PESs) have been calculated for the lowest electronic states of NCO, CNO and CON isomers, using internally contracted Multi Reference Configuration Interaction (MRCI) and Coupled-Clusters RCCSD(T) ab initio methods. For the low lying doublet and quartet excited states of the three isomers, the N-CO, O-CN, C-NO and C-ON collinear dissociation paths were mapped by the Complete Active Space SCF (CASSCF) approach and the energy variations with the bending coordinate have been explored. Several regions of conical intersections have been located and the spin-orbit interactions between states of different spin symmetry have been evaluated in the region of intersections of these states. The analysis of the PESs allows one to identify the main interactions governing the reactivity of the lowest electronic states. The NCO and CNO isomers have stable X2? electronic ground states, for CON the X2? ground state is separated from the dissociative [CO + N] asymptote by a barrier of 0.11 eV and crosses the dissociative 4? - state close to its minimum. At their equilibrium ground state geometries the spin-orbit interactions ASO between the two electronic components of the X2? states were calculated to be -95.6, -109.6 and -57.1 cm-1 for NCO, CNO and CON, respectively. The predissociation of the vibrational levels of the A2?+ and B2? states of NCO has been explained.

Yazidi, O.; Gritli, H.; Chambaud, G.

200

Simulation of Command and Control in the Conflict Model (ConMod).  

National Technical Information Service (NTIS)

The Conflict Model (ConMod) is an analytic computer model for simulating military conflict at the corps and echelons above corps levels. The model addresses operational concepts of air and ground forces engaged in deep, rear, and close combat. The model s...

Y. H. Chiu C. D. Jones G. D. Kreis S. C. Simonson S. M. Strange

1987-01-01

201

Crack and cook: A simple and quick process for elimination of concanavalin A (Con A) from Canavalia seeds  

Microsoft Academic Search

The most nutritionally important antinutritional factor in the Canavalia seeds is Concanavalin A (Con A) which takes at least 3h of cooking at 96°C to inactivate. The effect of breaking the seeds into smaller pieces before cooking on the Con A content was investigated. Whole seeds of Canavalia ensiformis (jackbean) and Canavalia ensiformis seeds that were broken into smaller pieces

A. B. I Udedibie; C. R Carlini

1998-01-01

202

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

Federal Register 2010, 2011, 2012, 2013

...Draft Decision on GexCon US, Inc. Petition for Approval of Flame Acceleration Simulator AGENCY: Pipeline and Hazardous Materials...Draft Decision on GexCon US, Inc.'s petition for approval of Flame Acceleration Simulator (FLACS). The Draft Decision is...

2011-09-01

203

Uso de hábitats modificados por aves dependientes de bosque tropical en la región caribeña de Guatemala  

Microsoft Academic Search

Modified-habitat use by tropical forest-dependent birds in the Caribbean region of Guatemala. As natural areas are reduced into isolated remnants, the importance of secondary habitats for species conser- vation will increase. Consequently, the conservation value of human-modified or created secondary habitats must be determined. in this study, we evaluated the conservation potential of three habitats associated to cattle ranching (riparian

Alexis Cerezo; Chandler S. Robbins; Barbara Dowell

204

Medio EMJH modificado para el cultivo de Leptospira interrogans serogrupo Ballum  

Microsoft Academic Search

Modified EMJH medium for cultivation of Leptospira interrogans serogroup Ballum. Strains within the Ballum serogroup of spirochete Leptospira show fastidious growth with more exigent nutritional requirements than those of other Leptospira pathogenic strains. The influence of 37 nutritional compounds on the growth of Leptospira interrogans serogroup Ballum was investigated employing the synthetic EMJH medium as the base for the study.

A. GONZÁLEZ; R. BORRERO; J. RUIZ; N. BATISTA; Y. FERNÁNDEZ; Y. VALDÉS; M. GONZÁLEZ

205

Cultivos genéticamente modificados: las promesas y las buenas intenciones no bastan  

Microsoft Academic Search

Genetically modified crops: promises and good intentions are not enough (refutation to Espinoza et al. 2004, Rev. Biol. Trop. 52 (3): 727-732). The arguments presented by Espinoza et al. in their paper \\

Jaime E. García

206

GENETICALLY MODIFIED FOOD CROPS AND PUBLIC HEALTH Cultivos alimenticios genéticamente modificados y salud pública  

Microsoft Academic Search

The progress made in plant biotechnology has provided an opportunity to new food crops being developed having desirable traits for improving crop yield, reducing the use of agrochemicals and adding nutritional properties to staple crops. However, genetically modified (GM) crops have become a subject of intense debate in which opponents argue that GM crops represent a threat to individual freedom,

ORLANDO ACOSTA

207

Deposição de filmes de ZEI 8% em mol por sistema de spray pirólise modificado  

Microsoft Academic Search

In this work zirconia stabilized with itria films 8 mol% (8YSZ) had been produced, applied as electrolytes for solid oxide fuel cell (SOFC), deposited in quartz substrate spray-pyrolysis technique and treated at 1000ºC. For attainment of films a system deposition for spray-pyrolysis modified according to patent deposited in INPI was used, that if compared with traditional system where atomized is

C. H. M. Rodrigues; M. Toniato; H. R. Paes Jr

2008-01-01

208

DETECCIÓN DE PRODUCTOS DE MAIZ GENETICAMENTE MODIFICADOS POR LA REACCIÓN EN CADENA DE LA POLIMERASA  

Microsoft Academic Search

A polymerase chain reaction (PCR) was applied to detect genetically modified (GM) maize and soybean food product, using specific 35S promoter primers for inserted chimerical genes in maize or soybean. The PCR detected food products that include ingredients obtained from GMOs in maize grains and flour, as well as processed in foods such as tortillas (Mexican crepe), corn chips, corn

A. Mendoza; S. Fernández; M. A. Cruz; M. A. Rodríguez-Perez; Barrera Saldaña; Elias Piña

2006-01-01

209

O consumo de alimentos derivados de organismos geneticamente modificados e a saúde humana e animal  

Microsoft Academic Search

A transformação genética de plantas é uma ferramenta extraordinária da biotecnologia, que permite o aumento da produtividade dos cultivos e a melhoria da qualidade nutricional dos alimentos. Ela também permite expandir o uso das plantas para áreas até hoje inexploradas, como a síntese de produtos em biofábricas. Muitos alimentos consumidos atualmente já são produzidos - totalmente ou em parte -

Marcelo Gravina de Moraes

210

ConBr, a lectin from Canavalia brasiliensis seeds, protects against quinolinic acid-induced seizures in mice.  

PubMed

Lectins are proteins capable of reversible binding to carbohydrates or glycoconjugates. In the central nervous system of mammals, lectins with affinity for mannose/glucose or galactose can modulate cellular communication. ConBr, a lectin isolated from the seeds of Canavalia brasiliensis, previously showed antidepressant effect in the forced swimming test in mice, with involvement of the monoaminergic system. In this study, we investigated the neuroprotective effects of ConBr against quinolinic acid (QA), a well-known NMDA agonist that produces severe neurotoxicity when administered in vivo. ConBr (10 ?g/site) administered via intracerebroventricular (i.c.v.) showed a neuroprotective activity against seizures induced by QA (36.8 nmol/site; i.c.v.) when administered 15 min prior to QA, with a percentage of protection around 50%. ConBr was also able to significantly decrease the severity of the seizures but without changes in the latency of the first convulsion or the duration of the seizures. This effect was dependent on the structural integrity of the ConBr protein and its binding capacity to oligosaccharides residues. ConA, a lectin with high similarity to ConBr, did not reverse the QA-induced seizures. Moreover, ConBr was able to protect against hippocampal cell death caused by QA, which was measured by propidium iodide incorporation. QA caused activation of JNK2 and improved the phosphorylation of Ser831 and 845 on the AMPA receptor GluR1 subunit, and both of these effects were counteracted by ConBr. Our data suggest that the lectin ConBr may exert a modulatory action on NMDA receptors, which inhibits its activity in response to QA. PMID:21948344

Russi, Michael A; Vandresen-Filho, Samuel; Rieger, Débora K; Costa, Ana Paula; Lopes, Mark W; Cunha, Rodrigo M S; Teixeira, Edson H; Nascimento, Kyria S; Cavada, Benildo S; Tasca, Carla I; Leal, Rodrigo B

2012-02-01

211

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

212

Disfrute del sol con cuidado -- Cualquier persona puede padecer cáncer de piel  

Cancer.gov

Está bien pasar algún tiempo en el sol, pero usted debe saber que las personas de piel más oscura –incluso muchos hispanos o latinos– tienen riesgo de padecer cáncer de piel. Siempre que pueda, evite exponerse al sol, especialmente entre las 10 a.m. y las 4 p.m., cuando los rayos del sol son más fuertes. Si trabaja o juega al aire libre, cúbrase y protéjase la piel con prendas de vestir, sombreros, lentes, filtros solares.

213

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

Cancer.gov

I-ConFIRM (The International Consortium for the Investigation of Renal Malignancies) was formed in 2013 to promote international, multidisciplinary collaborations to advance our understanding of the etiology and outcomes of kidney cancer. The Consortium is comprised of international investigators and clinicians who have ongoing or completed studies relating to kidney cancer. In its initial phase, the Consortium will undertake research projects that pool existing data across studies as well as developing other collaborative research projects.

214

Disfrute del sol con cuidado -- Cualquier persona puede padecer cáncer de piel  

Cancer.gov

Está bien pasar algún tiempo al aire libre, pero usted debe saber que las personas de piel más oscura –incluso muchos hispanos o latinos– tienen riesgo de padecer cáncer de piel. Siempre que pueda, evite exponerse al sol, especialmente entre las 10 a.m. y las 4 p.m., cuando los rayos del sol son más fuertes. Si trabaja o juega al aire libre, cúbrase y protéjase la piel con prendas de vestir, sombreros, lentes, filtros solares.

215

Pro/con debate: Is etomidate safe in hemodynamically unstable critically ill patients?  

PubMed Central

Etomidate is an induction agent known for its smooth intubating conditions and cardiovascular stability. Studies, however, have shown that a single dose of etomidate can result in a prolonged adrenal insufficiency. The impact of this in patients with sepsis has been a matter for debate. This review presents a pro/con case for using etomidate in hemodynamically unstable critically ill patients and provides guidance for alternative induction techniques and when the use of etomidate might be justified despite these concerns.

2012-01-01

216

Estudio fotométrico y espectroscópico de dos cúmulos abiertos jóvenes del disco con apariencia globular  

NASA Astrophysics Data System (ADS)

Se presentan y discuten resultados obtenidos en el CASLEO y en el Observatorio de Las Campanas de dos cúmulos abiertos compactos con apariencia globular: Westerlund1 (BH197), ubicado en dirección hacia el centro galáctico, y Westerlund2. A partir de espectroscopía CCD integrada de ambos e imágenes CCD en las bandas VI obtenidas para el primero de ellos, se derivan sus parámetros fundamentales y se examinan sus apariencias estructurales. Se encuentra que Westerlund1 es un cúmulo joven (7 ± 3 millones de años), ubicado sobre el plano galáctico a 1.0 ± 0.4 kpc del sol, en una región caracterizada por una absorción excepcionalmente elevada (Av~=13.0 mag), en tanto que Westerlund2 es también un cúmulo joven (4-6 millones de años) ubicado sobre el plano, en una región afectada por una absorción menor (Av~=5.7 mag). Desde el punto de vista estructural, Westerlund 1 se presenta como uno de los pocos cúmulos abiertos jóvenes de la Galaxia con apariencia tipicamente globular, en contraste con los cúmulos azules de las Nubes de Magallanes en los cuales la apariencia globular constituye un fenómeno común. Westerlund2, aunque menos rico en estrellas, puede también ser incluído dentro de esta interesante clase de objetos.

Piatti, A. E.; Clariá, J. J.; Bica, E.

217

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

SciTech Connect

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.

NONE

1994-12-01

218

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

219

Correlación entre la estructura de bandas y las propiedades físicas de óxidos cerámicos de estructura perovskita con metales de transición (I): Propiedades de conducción electrónica  

Microsoft Academic Search

En este artículo se revisa los principales modelos teóricos, que pretenden dar una explicación sobre las propiedades de con- ducción electrónica de óxidos cerámicos con estructura perovskita, que incluyen en la posición B metales de transición del primer período (Fe, Co, Ni, Mn), en conexión con su estructura de bandas y el carácter de sus electrones más externos, así como

L. SÁNCHEZ; J. R. JURADO

220

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

PubMed

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

Yoder, Christi A; Miller, Lowell A

2010-12-16

221

Extenso estudio realizado en muchos centros demuestra que hay una precisión comparable de la colonoscopia virtual con la colonoscopia convencional  

Cancer.gov

Según los resultados del Estudio Nacional de Colografía de Tomografía Computarizada de la American College of Radiology Imaging Network, ACRIN, la colografía de tomografía computarizada, también conocida como colonoscopia virtual, es comparable a la colonoscopia convencional en su capacidad para detectar con precisión cáncer y pólipos precancerosos y podría servir como examen selectivo inicial de detección de cáncer colorrectal. La colonoscopia convencional usa un tubo largo, flexible, con cámara, para ver el revestimiento del colon.

222

Nitrogen-detected CAN and CON experiments as alternative experiments for main chain NMR resonance assignments  

PubMed Central

Heteronuclear direct-detection experiments, which utilize the slower relaxation properties of low ? nuclei, such as 13C have recently been proposed for sequence-specific assignment and structural analyses of large, unstructured, and/or paramagnetic proteins. Here we present two novel 15N direct-detection experiments. The CAN experiment sequentially connects amide 15N resonances using 13C? chemical shift matching, and the CON experiment connects the preceding 13C? nuclei. When starting from the same carbon polarization, the intensities of nitrogen signals detected in the CAN or CON experiments would be expected four times lower than those of carbon resonances observed in the corresponding 13C-detecting experiment, NCA-DIPAP or NCO-IPAP (Bermel et al. 2006b; Takeuchi et al. 2008). However, the disadvantage due to the lower ? is counteracted by the slower 15N transverse relaxation during detection, the possibility for more efficient decoupling in both dimensions, and relaxation optimized properties of the pulse sequences. As a result, the median S/N in the 15N observe CAN experiment is 16% higher than in the 13C observe NCA-DIPAP experiment. In addition, significantly higher sensitivity was observed for those residues that are hard to detect in the NCA-DIPAP experiment, such as Gly, Ser and residues with high-field C? resonances. Both CAN and CON experiments are able to detect Pro resonances that would not be observed in conventional proton-detected experiments. In addition, those experiments are free from problems of incomplete deuterium-to-proton back exchange in amide positions of perdeuterated proteins expressed in D2O. Thus, these features and the superior resolution of 15N-detected experiments provide an attractive alternative for main chain assignments. The experiments are demonstrated with the small model protein GB1 at conditions simulating a 150 kDa protein, and the 52 kDa glutathione S-transferase dimer, GST.

Takeuchi, Koh; Heffron, Gregory; Sun, Zhen-Yu J.; Frueh, Dominique P.

2010-01-01

223

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

PubMed Central

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.

2009-01-01

224

A theoretical study of the rovibronic spectra of CNO, NCO and CON  

NASA Astrophysics Data System (ADS)

Variational calculations of the rovibronic spectra of the three isomers NCO, CNO and CON in their X2? electronic ground state have been performed. The calculations were done in an attempt to calibrate a computed ab initio potential, based on the complete active space second-order perturbation theory (CASPT2) approach, against experimental vibrational data. Comparison with experiment for the NCO isomer indicates that the theoretical potential is a little flat. It is shown that minor changes to the quadratic force field parameters lead to a substantial improvement in the accuracy.

Persson, B. Joakim; Roos, Björn O.; Carter, Stuart

225

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

PubMed

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

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

2007-11-01

226

Preparation of stimulus responsive multiple emulsions by membrane emulsification using con a as biochemical sensor.  

PubMed

In this work, a novel strategy for the controlled fabrication of biomolecular stimulus responsive water-in-oil-in-water (W/O/W) multiple emulsion using the membrane emulsification process was investigated. The emulsions interface was functionalized with a biomolecule able to function as a receptor for a target compound. The interaction between the biomolecular receptor and target stimulus activated the release of bioactive molecules contained within the structured emulsion. A glucose sensitive emulsion was investigated as a model study case. Concanavalin A (Con A) was used as the biomolecular glucose sensor. Various physicochemical strategies for stimulus responsive materials formulation are available in literature, but the preparation of biomolecule-responsive emulsions has been explored for the first time in this paper. The development of novel drug delivery systems requires advanced and highly precise techniques to obtain their particular properties and targeting requirements. The present study has proven the flexibility and suitability of membrane emulsification for the preparation of stable and functional multiple emulsions containing Con A as interfacial biomolecular receptor able to activate the release of a bioactive molecule as a consequence of interaction with the glucose target molecule. The influence of emulsion interfacial composition and membrane emulsification operating conditions on droplets stability and functional properties have been investigated. The release of the bioactive molecule as a function of glucose stimulus and its concentration has been demonstrated. PMID:21404264

Piacentini, Emma; Drioli, Enrico; Giorno, Lidietta

2011-04-01

227

Antiviral and antitumor effects of a human interferon analog, IFN-alpha Con 1, assessed in hamsters.  

PubMed

An analog of human alpha-and beta-interferons (IFN-alpha and -beta) (generally consisting of the most frequently observed amino acid residue at each position in the molecule) has pronounced antiviral and antiproliferative activity in human and hamster cells. Intraperitoneal administration of this analog (designated IFN-alpha Con 1) to hamsters at 10(6) to 10(8) U/kg resulted in proportional increases in plasma concentrations through 6 h of monitoring. IFN-alpha Con 1 at these doses effectively limited encephalomyocarditis virus (EMCV) infections of hamsters. A natural human IFN-alpha preparation was also active against virus infections in hamsters. The antitumor activity of IFN-alpha Con 1 and natural human IFN-alpha was assessed in hamsters inoculated with lethal TBD932 lymphosarcoma. Various IFN treatment schedules resulted in prolonged survival following tumor challenge. IFN-alpha Con 1 administered at 10(5) to 10(6) U/hamster daily for 9-12 days following tumor challenge was effective in delaying tumor development, as was a natural human IFN-alpha preparation. The efficacies of combined IFN and cyclophosphamide therapies were determined. Unlike the natural human subtype IFN-alpha A, IFN-alpha Con 1 did not diminish the efficacy of cyclophosphamide (2.5 mg/hamster for 3 days) against the lymphosarcoma. However, an ineffective dose of cyclophosphamide (0.05 mg/hamster for 3 days) when combined with IFN-alpha Con 1 treatment showed enhanced antitumor activity. Combinations of cimetidine (16 mg/hamster for 4 days) and IFN-alpha Con 1 treatment did not prolong survival in this model system. PMID:3021874

Altrock, B W; Fagin, K D; Hockman, H R; Fish, E N; Goldstein, L; Chang, D; Duker, K; Stebbing, N

1986-08-01

228

Multi-wall carbon nanotube-polyaniline biosensor based on lectin-carbohydrate affinity for ultrasensitive detection of Con A.  

PubMed

In this paper, a novel method for detecting concanavalin A (Con A) was developed based on lectin-carbohydrate biospecific interactions. Multi-wall carbon nanotube-polyaniline (MWNT-PANI) nanocomposites, synthesized by in situ polymerization, were chosen to immobilize d-glucose through the Schiff-base reaction. The immobilized D-glucose showed high binding sensitivity and excellent selectivity to its target lectin, Con A. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), transmission electron microscopy (TEM) and atomic force microscopy (AFM) were applied to characterize the assembly process of the modified electrode. Due to the high affinity of Con A for D-glucose and high stability of the propounded sensing platform, the fabricated biosensor achieved ultrasensitive detection of Con A with good sensitivity, acceptable reproducibility and stability. The changes of response current were proportional to the Con A concentrations from 3.3 pM to 9.3 nM, with a detection limit of 1.0 pM. Therefore, the combination of MWNT-PANI nanocomposites and the special binding force between lectin and carbohydrate provides an efficient and promising platform for the fabrication of bioelectrochemical devices. PMID:22387041

Hu, Fangxin; Chen, Shihong; Wang, Chengyan; Yuan, Ruo; Xiang, Yun; Wang, Cun

2012-04-15

229

Pros and cons of healthcare information technology implementation: the pros win.  

PubMed

Countless studies and investigations have been performed siding either for or against the implementation of technology in the healthcare setting. This article presents both sides of this debate, with an obvious conclusion that the pros of this debate win. The practice of information technology in the medical domain lags behind its knowledge and discovery by at least 7 years. The key to closing this gap is to show, through various studies, how information technology systems provide decision support to users at the point in time when decisions are needed. What the reader will obtain from this article is that the pros for information technology implementation in healthcare settings weigh much more and have a greater effect than the cons. PMID:17149039

Maffei, Roxana

2006-01-01

230

A new look at the infrared spectrum of the weakly bound CO-N2 complex.  

PubMed

A broad-band (2135-2165 cm(-1)) infrared spectrum of the CO-N2 van der Waals complex is obtained, using a tunable quantum cascade laser to probe a pulsed supersonic expansion from a slit jet source. Analysis of the spectrum results in the characterization of four new 'stacks' of rotational levels for CO-orthoN2 (all in the v(CO) = 1 upper state) and five new stacks for CO-paraN2 (three in the upper state and two in the vCO = 0 lower state). This considerably expands our knowledge of a rather fundamental weakly bound complex and should lead to improved determinations of the intermolecular forces governing interactions between the carbon monoxide and nitrogen molecules. PMID:24090526

Rezaei, Mojtaba; Michaelian, K H; Moazzen-Ahmadi, N; McKellar, A R W

2013-12-19

231

Nonlinear optical effects in amorphous-like SiCON films  

NASA Astrophysics Data System (ADS)

We have found that IR bicolor coherent poling of the SiCON films with the pulsed IR 200 ps laser pulses causes sufficiently high values of the second-order optical susceptibilities. The dependence of the second-order susceptibility versus the fundamental power density as well as versus the time of the optical poling and writing/fundamental beam ratios indicate on substantial role of the N / C ratio. Maximally achieved value of the second-order optical susceptibility was equal to about 9 pm / V. In the case of our films we have shown that optimal incident angle of the writing beam with respect to the sample's surface for the achievement of optimal grating is equal to about 67°. Optimal ratio between the fundamental and writing beams was equal about 30. The grating is destroyed during the 10 min after the interruption of optical treatment.

Kityk, I. V.; Mandracci, P.

2005-06-01

232

Con-A-CNT (Carbon Nanotube) Conjugate with Short Wave Near-Infrared (SWIR) Laser Ablation for Tumor Therapy.  

National Technical Information Service (NTIS)

Using the characteristics of T cell mitogen called lectin protein from the jack-bean Canavalia ensiformis Concanavalin A (Con-A) with dual activities, cytotoxicity and immunomodulation, we have shown it has a therapeutic effect on hepatoma. Injection of C...

C. Peng H. Lei H. Szu M. Tang

2010-01-01

233

Comparación de resultados del método de clasificación de órbitas por análisis de frecuencias con el método de exponentes de Lyapunov  

NASA Astrophysics Data System (ADS)

Hemos realizado extensas comparaciones del método de análisis de frecuencias con el de exponentes de Lyapunov. El primero resulta claramente superior por las siguientes razones: 1) permite distinguir distintos tipos de órbitas y no sólo si son regulares o caóticas 2) es mucho más veloz requiriendo mucho menos tiempo de cómputo. La concordancia de resultados es, en general, buena y se discuten algunas discrepancias.

Carpintero, D. D.; Muzzio, J. C.; Wachlin, F. C.

234

JAPÓN: EVOLUCIÓN DE LA POLÍTICA DE SEGURIDAD EN EL MARCO DE LA ALIANZA ESTRATÉGICA CON LOS EE.UU  

Microsoft Academic Search

Japón quedó devastado al concluir la Segunda Guerra Mundial. En ese entonces, una de las vías que encontró para salir de la crisis en que había quedado inmerso, fue dedicarse por completo a la recuperación económica. Para ello, en 1951, firma el Tratado de Seguridad con los EE.UU., a partir de la Doctrina Yoshida, que consistía, en la concentración de

Yunyslka González Vaguéz

2009-01-01

235

In vivo normobaric oxygen exposure depresses spleen cell in vitro Con A response. Effects of 2-mercaptoethanol and peritoneal cells.  

PubMed Central

Normobaric O2 exposure decreased spleen cell (SC) response to T cell mitogen Con A. 3H-TdR incorporation of SC from O2 exposed mice (O2SC) compared to those of control mice (Air SC) decreased significantly after 72 and 87 h O2 exposure. The dose response kinetics to Con A were identical in O2SC or Air SC. Increasing SC number did not restore the response to Con A and the depressed hyperoxic effect was not related to suppressor cells in the spleen of O2 exposed mice. Response of O2SC to Con A was restored by the thiol compound 2-mercaptoethanol (2-ME), and the degree of restoration by 2-ME, was inversely proportional to the depressed response. Addition of intact peritoneal cells (PC) induced restoration within the same range as 2-ME. Restoration of the mitogenic response by 2-ME involved antioxidant properties and suggested that macrophages were functionally injured by O2 exposure. In cases where mitogen response was highly depressed, restoration was only partial; in these conditions in vivo O2 injury probably involved both macrophages and splenic T cells. The mechanisms of O2 toxicity have been discussed in terms of free radical generation under hyperoxic conditions.

Gougerot-Pocidalo, M A; Fay, M; Pocidalo, J J

1984-01-01

236

Treatment of plutonium contaminated soil/sediment from the Mound site using the ACT*DE*CON{sup SM} process  

SciTech Connect

The removal and/or treatment of contaminated soil is a major problem facing the US DOE. The EG&G Mound Applied Technologies site in Miamisburg, Ohio, has an estimated 1.5 million cubic feet of soils from past disposal and waste burial practices awaiting remediation from plutonium contamination. This amount includes sediment from the Miami-Erie Canal that was contaminated in 1969 following a pipe- rupture accident. Conventional soil washing techniques that use particle separation would generate too large a waste volume to be economically feasible. Therefore, innovative technologies are needed for the cleanup. The ACT*DE*CON process was developed by SELENTEC for washing soils to selectively dissolve and remove heavy metals and radionuclides. ACT*DE*CON chemically dissolves and removes heavy metals and radionuclides from soils and sediments into an aqueous medium. The ACT*DE*CON process uses oxidative carbonate/chelant chemistry to dissolve the contaminant from the sediment and hold the contaminant in solution. The objective of recent work was to document the proves conditions necessary to achieve the Mound-site and regulatory-cleanup goals using the ACT*DE*CON technology.

Negri, M.C. [Argonne National Lab., IL (United States); Swift, N.A. [SELENTEC, Atlanta, GA (United States); North, J.P. [Rust Remedial Service, Inc., Anderson, SC (United States)

1996-10-01

237

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

PubMed

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

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

2009-04-01

238

Pro/con ethics debate: is nonheart-beating organ donation ethically acceptable?  

PubMed

This pro/con debate explores the ethical issues surrounding nonheart-beating organ donation (NHBD), a source of considerable controversy. It is estimated that NHBD can increase the number of organs available for transplant by 25% at a time of great need. However, should NHBD be ethically acceptable? In support of NHBD, it may be acceptable practice if there is a separation of the rationale to withdraw life support/to withhold cardiopulmonary resuscitation from the decision to recover organs, if no conflicts of interest exist, if a waiting time precluding spontaneous return of circulation is included, and if NHBD conforms to a standardized protocol. Against NHBD, there are questions regarding the ambiguity and cultural perspectives of death, regarding whether a separation of rationale between withdrawal and donation is sufficient to preclude conflicts of interest, and regarding whether variable protocols arise that subordinate the patient to the goal of donation. Such concerns suggest NHBD may damage the trust in patient-physician relationships and may adversely affect organ donation rates. PMID:12133176

Whetstine, Leslie; Bowman, Kerry; Hawryluck, Laura

2002-06-01

239

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

PubMed Central

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.

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

2014-01-01

240

Ground and lowest-lying electronic states of CoN. A multiconfigurational study.  

PubMed

The lowest-lying X1Sigma+, a3Phi, b3II, c5Delta, A1Phi, and B1II electronic states of CoN have been investigated at the ab initio MRCI and MS-CASPT2 levels, with extended atomic basis sets and inclusion of scalar relativistic effects. Among the singlet states, the A1Phi and B1II states have been described for the first time. Potential energy curves, excitation energies, spectroscopic constants, and bonding character for all states are reported. Comparison with other early transition-metal nitrides (ScN, TiN, VN, and CrN), isoelectronic (NiC) and isovalent (RhN and IrN) species has been made, besides analyzing the B1II <=> X1+ electronic transition in terms of Franck-Condon factors, Einstein coefficients, and radiative lifetimes. At both levels of theory, the following energetic order has been obtained: X1Sigma+, a3Phi, b3II, c5Delta, A1Phi, and B1II, with good agreement with experimental results. In contrast, previous DFT and MRCI calculations predicted the ground state to be the 5Delta state. PMID:17181357

Gobbo, João Paulo; Borin, Antonio Carlos

2006-12-28

241

Structural and magnetic properties of N doped Fe_mCon superlattices: First principles calculations.  

NASA Astrophysics Data System (ADS)

Magnetic alloys and multilayers have been widely investigated because of their potential for magnetic device applications. In this, materials exhibiting high magnetization as well as good soft magnetic properties are desirable. We investigated the magnetic and structural properties of Fe_mCon superlattices with various compositions via first principles local density full potential linearized augmented plane wave (FLAPW) method^(1) calculations. For the 25% Co composition which showed the maximum magnetic moments, we inserted N atoms to make (Fe_3Co)_4N_2, in order to examine the possible magnetic enhancement by N, which has drawn much attention since the first report (in 1972) of a giant magnetic moment for the quasi-stable ?-Fe_16N_2. The structural optimization was fully accomplished by total energy and atomic force calculations. Despite the lattice expansion due to the N insertion, the magnetic moment of (Fe_3Co)_4N2 was found to be reduced from the value of the Fe_3Co superlattice by the strong hybridization of N with Fe and Co. (1) E. Wimmer, H. Krakauer, M. Weinert and A. J. Freeman, Phys. Rev. B 24, 864 (1981).

Kim, Miyoung; Freeman, A. J.

2001-03-01

242

Estereotipos Sexuales y su Relaci?n con Conductas Sexuales Riesgosas1,2,3  

PubMed Central

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.

Perez-Jimenez, David; Orengo-Aguayo, Rosaura E.

2012-01-01

243

Thromboprophylaxis in carriers of antiphospholipid antibodies (APL) without previous thrombosis: "Pros" and "Cons".  

PubMed

The presence of anti-phospholipid (aPL) is necessary but not sufficient to induce a thrombotic event. The "second hit" hypothesis suggested that an additional trigger may be needed to develop a vascular event in aPL carriers. In this article, pro and con of primary thromboprophylaxis in aPL carriers is deeply discussed, concluding that univocal data are not available, due to conflicting results of available clinical trials. However, in clinical practice the primary thromboprophylaxis is not indicated in all unselected asymptomatic aPL carriers, and the best strategy begin with the assessment of the peculiar risk profile of the subject. Thus, it is mandatory to eliminate modifiable prothrombotic risk factors (i.e. smoking, oral contraceptive), to treat the irreversible risk factors (i.e. hypertension, diabetes) and to introduce an aggressive prophylaxis with subcutaneous LMWH in high-risk situations (i.e. surgical procedures with prolonged immobilization). A different evaluation should be addressed to aPL carriers with a concomitant autoimmune disease that are considered as an additional pro-thrombotic risk factor. Similarly, concomitant positivity for more than one anti-phospholipid test confer a stronger risk of developing the thrombotic manifestations. Specific trials with larger cohorts of patients are needed to better clarify this issue. PMID:22036825

Ceccarelli, Fulvia; Chighizola, Cecilia; Finazzi, Guido; Meroni, Pier Luigi; Valesini, Guido

2012-06-01

244

Long-Acting Injectable Antipsychotics for First-Episode Schizophrenia: The Pros and Cons  

PubMed Central

Clinical and psychosocial deterioration associated with schizophrenia occurs within the first few years following the onset of the illness. Therefore, to improve the long-term prognosis, it is important to provide schizophrenia patients with intensive treatment following their first episode. Relapse is highly associated with partial medication adherence or nonadherence in patients with first-episode schizophrenia. Recent studies suggest that long-acting injectable (LAI) antipsychotics compared with oral antipsychotics are more effective for medication adherence and relapse prevention. Moreover, some clinical guidelines for the treatment of schizophrenia suggested that LAI antipsychotics should be considered when patients are nonadherent “at any stage.” Decreased compliance is a common cause of relapse during the initial stages of the disease. Therefore, LAI antipsychotics should be highly considered when treating patients with first-episode schizophrenia. In the present paper, clinical trial data and current guidelines on the use of LAI antipsychotics for first-episode schizophrenia are discussed as well as the pros and cons of this treatment option.

Kim, Borah; Lee, Sang-Hyuk; Yang, Yen Kuang; Park, Jong-Il; Chung, Young-Chul

2012-01-01

245

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

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

246

Vibrational relaxation of CO(n = 1) in collisions with He  

SciTech Connect

We present a full ab initio study of vibrational relaxation of CO(n = 1) in collisions with /sup 3/He and /sup 4/He. The vibrational coordinate dependence of the interaction potential is calculated directly. Dynamical calculations are performed within the IOS and the CS approximation. The IOS cross sections agree very well with the corresponding CS results for both He isotopes, however, the ratio IOS/CS shows a different energy behavior for /sup 3/He and /sup 4/He, respectively. The CS rates for /sup 3/He agree extremely well with the experimental relaxation rates. Although only the reduced mass is changed for /sup 4/He the agreement with experiment is less favorable in this case. It is explicitly demonstrated that the often used procedure to extract the vibrational coordinate dependence of the interaction potential from a dumbbell fit of the rigid-rotor surface is wrong for He--CO. For /sup 3/He the corresponding cross sections are 3--10 times smaller than those obtained form the ab initio potential although the vibrationally elastic parts of the interaction potential are identical.

Schinke, R.; Diercksen, G.H.F.

1985-11-01

247

NIVEL DE CONOCIMIENTOS SOBRE METODOS ANTICONCEPTIVOS PREVIOS AL INICIO DE LAS RELACIONES SEXUALES Y SU COMPARACION CON EL NIVEL DE CONOCIMIENTOS ACTUALES EN ESTUDIANTES DE MEDICINA  

Microsoft Academic Search

RESUMEN: Introducción: Con entrenamiento adecuado, los estudiantes de medicina pueden convertirse en lí- deres de opinión con futura injerencia sobre las políticas de salud, así como ayudar al público a en- tender las consecuencias de los embarazos indeseados y del aborto. El objetivo del presente estudio ha sido examinar el nivel de conocimientos sobre métodos anticonceptivos (MAC) previos al inicio

Guillermo Horacio; Cáceres Pallavidino; Echevarría Avellaneda; Domingo José Pomares

248

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

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

249

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

PubMed Central

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.

Epstein, Nancy E.

2012-01-01

250

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

PubMed

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

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

2014-08-01

251

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

PubMed Central

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.

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

252

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

253

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

254

Structural analysis of ConBr reveals molecular correlation between the carbohydrate recognition domain and endothelial NO synthase activation.  

PubMed

Diocleinae lectins are highly homologous in their primary structure which features metal binding sites and a carbohydrate recognition domain (CRD). Differences in the biological activity of legume lectins have been widely investigated using hemagglutination inhibition assays, isothermal titration microcalorimetry and co-crystallization with mono- and oligosaccharides. Here we report a new lectin crystal structure (ConBr) extracted from seeds of Canavalia brasiliensis, predict dimannoside binding by docking, identify the ?-aminobutyric acid (Abu) binding pocket and compare the CRD of ConBr to that of homologous lectins. Based on the hypothesis that the carbohydrate affinity of lectins depends on CRD configuration, the relationship between tridimensional structure and endothelial NO synthase activation was used to clarify differences in biological activity. Our study established a correlation between the position of CRD amino acid side chains and the stimulation of NO release from endothelium. PMID:21530490

Bezerra, Eduardo Henrique Salviano; Rocha, Bruno Anderson Matias; Nagano, Celso Shiniti; Bezerra, Gustavo de Arruda; Moura, Tales Rocha de; Bezerra, Maria Júlia Barbosa; Benevides, Raquel Guimarães; Sampaio, Alexandre Holanda; Assreuy, Ana Maria Sampaio; Delatorre, Plínio; Cavada, Benildo Sousa

2011-05-20

255

ConReg-R: Extrapolative recalibration of the empirical distribution of p-values to improve false discovery rate estimates  

PubMed Central

Background False discovery rate (FDR) control is commonly accepted as the most appropriate error control in multiple hypothesis testing problems. The accuracy of FDR estimation depends on the accuracy of the estimation of p-values from each test and validity of the underlying assumptions of the distribution. However, in many practical testing problems such as in genomics, the p-values could be under-estimated or over-estimated for many known or unknown reasons. Consequently, FDR estimation would then be influenced and lose its veracity. Results We propose a new extrapolative method called Constrained Regression Recalibration (ConReg-R) to recalibrate the empirical p-values by modeling their distribution to improve the FDR estimates. Our ConReg-R method is based on the observation that accurately estimated p-values from true null hypotheses follow uniform distribution and the observed distribution of p-values is indeed a mixture of distributions of p-values from true null hypotheses and true alternative hypotheses. Hence, ConReg-R recalibrates the observed p-values so that they exhibit the properties of an ideal empirical p-value distribution. The proportion of true null hypotheses (?0) and FDR are estimated after the recalibration. Conclusions ConReg-R provides an efficient way to improve the FDR estimates. It only requires the p-values from the tests and avoids permutation of the original test data. We demonstrate that the proposed method significantly improves FDR estimation on several gene expression datasets obtained from microarray and RNA-seq experiments. Reviewers The manuscript was reviewed by Prof. Vladimir Kuznetsov, Prof. Philippe Broet, and Prof. Hongfang Liu (nominated by Prof. Yuriy Gusev).

2011-01-01

256

Genotyping the HFE gene by melting point analysis with the LightCycler system: Pros and cons  

Microsoft Academic Search

The assay that combines rapid-cycle PCR with allele-specific fluorescent probe melting profiles performed on the Roche Diagnostics LightCycler is commonly employed for genotyping the HFE gene.We report three illustrative cases of the pros and cons of this method. In two cases, atypical melting curves allows the identification of new DNA substitutions in the HFE gene, whereas, in the third case,

V. Bach; M. J. Barceló; A. Altés; A. Remacha; J. Félez; M. Baiget

2006-01-01

257

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)

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.

Hales, Christopher A.; Chiles Con Pol Collaboration

2014-04-01

258

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

NASA Astrophysics Data System (ADS)

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.

Tuominen, Mark

2013-03-01

259

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

NASA Astrophysics Data System (ADS)

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.

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

260

ALMIDÓN MODIFICADO DE YUCA COMO SUSTITUTO ECONÓMICO DEL AGENTE SOLIDIFICANTE PARA MEDIOS DE CULTIVO DE TEJIDOS VEGETALES  

Microsoft Academic Search

SUMMARY Plant tissue culture methodologies were developed five dec- ades ago. However, expensive reagents and faulty technology transfer have prevented farmers in developing countries to ben- efit from these techniques. In Venezuela, cassava (Manihot esculenta Crantz) is a neglected crop harvested by poor farmers in marginal areas. Several constraints plot against large scale cassava cultivation, but the most important ones

Gustavo Romay; Juan Matehus; Armando Gerstl; Rodrigo Rueda; María A. Santana

2006-01-01

261

La implementación de acuerdos comerciales preferenciales en América Latina: Las experiencias de CH, CR, ES, PE en la implementación de las disposiciones sobre acceso a mercados en el marco de los tratados de libre comercio con Estados Unidos  

Microsoft Academic Search

Este estudio abordará los desafíos y dificultades asociadas con la implementación y administración de las disposiciones sobre acceso a mercados, con especial énfasis en aquellas relacionadas con aduanas y facilitación del comercio. El análisis se realizará para los Tratados de Libre Comercio de Chile - EE.UU; Perú - EE.UU y para el Tratado de Libre Comercio entre Estados Unidos, Centroamérica

Juan Luis Zuñiga; Brian Rankin Staples

2011-01-01

262

Antidepressant-like effect of Canavalia brasiliensis (ConBr) lectin in mice: Evidence for the involvement of the glutamatergic system.  

PubMed

Lectins recognize and reversibly bind to carbohydrates attached to proteins and lipids modulating a variety of signaling pathways. We previously showed that ConBr, a lectin from Canavalia brasiliensis seeds, produced an antidepressant-like effect in mice by modulating the monoaminergic neurotransmitter systems. Moreover, ConBr blocked hippocampal neurotoxicity induced by quinolinic acid in vivo and by glutamate in vitro, suggesting a neuroprotective activity of ConBr via glutamatergic system modulation. Therefore, the present study was undertaken to investigate the involvement of the N-methyl-d-aspartate (NMDA) receptor and the l-arginine-nitric oxide (NO) pathway in the antidepressant-like action displayed by ConBr in the forced swimming test (FST). With the aim of verifying the involvement of NMDA receptors in the antidepressant-like effect of ConBr (10?g/site, i.c.v.), an intracerebroventricular (i.c.v.) pretreatment with either NMDA (0.1pmol/site) or d-serine (30?g/site) was carried out. The results show that both treatments blocked the effect of ConBr. Furthermore, the coadministration of subeffective doses of the NMDA receptor antagonist MK-801 (0.001mg/kg, i.p.) or ketamine (0.1mg/kg, i.p.; NMDA receptor antagonist) and ConBr (0.1?g/site, i.c.v.) caused a synergistic reduction in immobility time. In order to verify the dependence of the l-arginine-NO-cGMP pathway, on the effect of ConBr in the FST, a pretreatment with the NO precursor, l-arginine (750mg/kg, i.p.), or the PDE5 inhibitor, sildenafil (5mg/kg, i.p.), was performed. Both drugs abolished the antidepressant-like action of ConBr. Finally, the administration of subeffective doses of the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 30pmol/site, i.c.v.) and ConBr (0.1?g/site, i.c.v.) produced a synergistic antidepressant-like effect in the FST. Taken together, the results suggest that the antidepressant-like effect of ConBr in the FST involves NMDA receptor inhibition and reduction in NO and cGMP synthesis. PMID:24650588

Rieger, Débora K; Costa, Ana Paula; Budni, Josiane; Moretti, Morgana; Barbosa, Sabrina Giovana Rocha; Nascimento, Kyria S; Teixeira, Edson H; Cavada, Benildo S; Rodrigues, Ana Lúcia S; Leal, Rodrigo B

2014-07-01

263

hI-con1, a factor VII-IgGFc chimeric protein targeting tissue factor for immunotherapy of uterine serous papillary carcinoma  

Microsoft Academic Search

BACKGROUND:Uterine serous papillary adenocarcinoma (USPC) is a highly aggressive variant of endometrial cancer. Human immuno- conjugate molecule (hI-con1) is an antibody-like molecule targeted against tissue factor (TF), composed of two human Factor VII (fVII) as the targeting domain, fused to human immunoglobulin (Ig) G1 Fc as an effector domain. We evaluated hI-con1 potential activity against primary chemotherapy-resistant USPC cell lines

E Cocco; Z Hu; C E Richter; S Bellone; F Casagrande; M Bellone; P Todeschini; G Krikun; D-A Silasi; M Azodi; P E Schwartz; T J Rutherford; N Buza; S Pecorelli; C J Lockwood; A D Santin

2010-01-01

264

No adverse effects of simultaneous vaccination with the immunocontraceptive GonaCon and a commercial rabies vaccine on rabies virus neutralizing antibody production in dogs.  

PubMed

Parenteral vaccination campaigns are integral to the elimination of canine rabies. To maximize herd immunity in dogs, immunocontraception provided at the time of rabies vaccination should reduce fecundity and dog abundance. GonaCon has been used successfully as an immunocontraceptive in a variety of mammals, and by inference, the dog would be an ideal candidate for testing. As an initial step in evaluating a combination-vaccination program, we assessed the effects of GonaCon on rabies virus neutralizing antibody production in dogs after administration of a veterinary rabies vaccine. Eighteen feral/free ranging dogs were included in this initial study: six were given GonaCon only, six were given rabies vaccination only, and six received GonaCon and rabies vaccination. Antibody levels were evaluated over 82 days. The use of the immunocontraceptive GonaCon did not affect the ability of dogs to seroconvert in response to the rabies vaccine. Thus, GonaCon provides a potential immunocontraceptive for use in combination with rabies vaccine to increase herd immunity and address dog population over abundance to better manage rabies. PMID:19925955

Bender, Scott C; Bergman, David L; Wenning, Krista M; Miller, Lowell A; Slate, Dennis; Jackson, Felix R; Rupprecht, Charles E

2009-11-27

265

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

PubMed

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

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

266

Aryl hydrocarbon receptor plays protective roles in ConA-induced hepatic injury by both suppressing IFN-? expression and inducing IL-22.  

PubMed

The aryl hydrocarbon receptor (AhR), a ligand-activated nuclear transcription factor, is known to mediate the toxic and carcinogenic effects of various environmental pollutants, while AhR has been shown to protect animals from various types of tissue injury. ConA-induced hepatitis is known as a mouse model of acute liver injury. Here, we found a protective role of AhR in ConA-induced hepatitis. AhR is induced in the liver during ConA-induced hepatitis, and Ahr (-/-) mice were highly sensitive to this model. Bone marrow chimera experiments indicate that Ahr (-/-) hematopoietic cells are responsible for hypersensitivity to ConA-induced hepatitis. We found that IFN-? from invariant NKT cells was up-regulated and IL-22 from innate lymphoid cells (ILCs) was abolished in Ahr (-/-) mice. In addition, IL-22 production was still observed in Rag2 (-/-) mice but it was severely reduced in Ahr (-/-) Rag2 (-/-) mice. ConA-induced IL-22 production was also dependent on retinoic acid-related orphan receptor ?t. These results show that AhR has crucial protective roles in ConA-induced liver injury via promoting IL-22 production from ILCs and suppressing IFN-? expression from NKT cells. PMID:24150244

Abe, Hiromi; Kimura, Akihiro; Tsuruta, Sanae; Fukaya, Tomohiro; Sakaguchi, Ryota; Morita, Rimpei; Sekiya, Takashi; Shichita, Takashi; Chayama, Kazuaki; Fujii-Kuriyama, Yoshiaki; Yoshimura, Akihiko

2014-03-01

267

Influence of parameter values and variances and algorithm architecture in ConsExpo model on modeled exposures.  

PubMed

This study evaluated the influence of parameter values and variances and model architecture on modeled exposures, and identified important data gaps that influence lack-of-knowledge-related uncertainty, using Consexpo 4.1 as an illustrative case study. Understanding the influential determinants in exposure estimates enables more informed and appropriate use of this model and the resulting exposure estimates. In exploring the influence of parameter placement in an algorithm and of the values and variances chosen to characterize the parameters within ConsExpo, "sensitive" and "important" parameters were identified: product amount, weight fraction, exposure duration, exposure time, and ventilation rate were deemed "important," or "always sensitive." With this awareness, exposure assessors can strategically focus on acquiring the most robust estimates for these parameters. ConsExpo relies predominantly on three algorithms to assess the default scenarios: inhalation vapors evaporation equation using the Langmuir mass transfer, the dermal instant application with diffusion through the skin, and the oral ingestion by direct uptake algorithm. These algorithms, which do not necessarily render health conservative estimates, account for 87, 89 and 59% of the inhalation, dermal and oral default scenario assessments,respectively, according them greater influence relative to the less frequently used algorithms. Default data provided in ConsExpo may be useful to initiate assessments, but are insufficient for determining exposure acceptability or setting policy, as parameters defined by highly uncertain values produce biased estimates that may not be health conservative. Furthermore, this lack-of-knowledge uncertainty makes the magnitude of this bias uncertain. Significant data gaps persist for product amount, exposure time, and exposure duration. These "important" parameters exert influence in requiring broad values and variances to account for their uncertainty. Prioritizing them for research will not only help fill a large and influential knowledge gap, but also lead to more accurate assessments and thus refine the studies informing policy decisions. PMID:24283337

Arnold, Susan F; Ramachandran, Gurumurthy

2014-01-01

268

Comparison of hydrogenated amorphous silicon germanium and nanocrystalline silicon for multijunction solar cells: pros, cons, and status  

Microsoft Academic Search

A comparison is made of hydrogenated amorphous silicon germanium (a-SiGe:H) and hydrogenated nanocrystalline silicon (nc-Si:H) for use in the bottom cell of a multijunction structure. In our laboratory, an initial active-area cell efficiency of 14.6% has been achieved in both a-Si:H\\/a-SiGe:H\\/a-SiGe:H and a-Si:H\\/a-SiGe:H\\/nc-Si:H triple-junction structures. Their light-soaked stabilized efficiencies are also similar. Pros, cons, issues, and status for using these

Jeffrey Yang; Baojie Yan; Guozhen Yue; Subhendu Guha

2005-01-01

269

SOBREPESO Y OBESIDAD EN NIÑOS Y ADOLESCENTES DE LA CIUDAD DE CORRIENTES ASOCIACIÓN CON FACTORES DE RIESGO CARDIOVASCULAR  

Microsoft Academic Search

sos, con predominio en varones (OR=1.46; IC=1.12-1.91; p=0.03). Actividad física semanal: 3.9 ± 2.9 hs. mayor en varones (p<0.001). Horas de sedentarismo: 3.2 ± 1.9. Antecedentes: obesidad materna 282 (13.3%), paterna 311 (14.7%), en ambos 116 (6.6%). Consumo regular de comidas grasas: 1711 (80.9%). PAS: 107.8 ± 13.6; PAD: 66.9 ± 11.5; PAM: 80.5 ± 10.1. Hipertensos 64 (3%) a

CARLOS A. MARTÍNEZ; JULIO O. IBÁÑEZ; CARLOS A. PATERNO; MIRTHA SEMENZA DE ROIG; MARÍA ITATÍ HEITZ; JORGE O. KRISKOVICH; GRISELDA R. DE BONIS; LIZ C. CÁCERES

2001-01-01

270

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

NASA Technical Reports Server (NTRS)

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).

Bagri, Durgadas S.

2009-01-01

271

Suspicion of acute appendicitis in the third trimester of pregnancy: pros and cons of a laparoscopic procedure.  

PubMed

The presentation of acute appendicitis during pregnancy may cause diagnostic and therapeutic difficulty. Delay in diagnosis may lead to increased maternal and fetal risk. Therefore, an aggressive surgical approach is mandatory, even though this may result in an increased number of appendectomies for normal appendices. Diagnostic laparoscopy, followed by laparoscopic appendectomy in case of inflammation, seems a logical strategy. We present the case of a 36-week pregnant woman who presented with suspicion of acute appendicitis. The pro and cons of a laparoscopic approach in the third trimester of pregnancy are discussed as is its safety by reviewing the literature. PMID:21985728

Donkervoort, S C; Boerma, D

2011-01-01

272

40 CFR 63.626 - Performance tests and compliance provisions.  

Code of Federal Regulations, 2013 CFR

...Where: Mp = total mass flow rate of phosphorus-bearing feed, metric ton/hr (ton...determine the mass flow rate (Mp ) of the phosphorus-bearing feed. (ii) The P2 O5...Analysis for Phosphate Rock, No. 3 PhosphorusâP2 O5 or Ca3 (PO4 )2 ,...

2013-07-01

273

P- T- t paths and post-metamorphic exhumation of the Day Nui Con Voi shear zone in Vietnam  

NASA Astrophysics Data System (ADS)

The Day Nui Con Voi belt in Vietnam is the southeasternmost part of the Red River shear zone in Asia. It is a narrow high-grade metamorphic core complex consisting of garnet-sillimanite-biotite gneisses, mylonite bands, amphibolite layers and migmatites. Geothermobarometric study of the complex revealed that the peak metamorphism took place under amphibolite-facies conditions of 690 -60 +30°C and 0.65±0.15 GPa and the subsequent mylonitization occurred under greenschist-facies conditions of ˜480°C and under 0.3 GPa. Fifteen synkinematic hornblende and biotite separates from gneisses, amphibolites and mylonites were dated with the K/Ar method. Hornblende separates from the Day Nui Con Voi give K-Ar ages of 26.4-28.5 Ma, and the biotite separates do give 24.5-24.7 Ma. Combination of thermobarometric and geochronological data yields the cooling history of 500°C at 28 Ma and 300°C at 24 Ma with a cooling rate of 70-110°C Ma -1, and 23 km post-metamorphic exhumation of the core complex. The first 16 km exhumation from the peak of metamorphism (at probably 31 Ma) to 28 Ma was triggered by the left-lateral strike-slip displacement of the Red River shear zone.

Nam, Tran Ngoc; Toriumi, Mitsuhiro; Itaya, Tetsumaru

1998-05-01

274

Dissection of the intracellular pathways in hepatocytes suggests a role for Jun kinase and IFN regulatory factor-1 in Con A-induced liver failure.  

PubMed

Con A administration results in dose-dependent immune-mediated liver injury. Cytokines are important to determine the outcome of liver failure in this model, and especially TNF-alpha and IFN-gamma directly contribute to hepatocyte damage. The intracellular pathways of these two cytokines, which eventually result in tissue destruction, are not well defined. Here we used anti-IFN-gamma Abs and adenoviral vectors that express molecules inhibiting distinct TNF-alpha-dependent pathways in hepatocytes to better understand the relevance of specific intracellular signaling cascades for Con A-induced liver failure. We show that activation of TNF-alpha- and IFN-gamma-dependent intracellular pathways occurs prior to the influx of immune-activated cells into the liver and that anti-TNF-alpha and anti-IFN-gamma neutralizing Abs cannot block infiltration of these cells. Blocking experiments with Abs and adenoviral vectors showed that NF-kappaB activation and the Fas-associated death domain protein/caspase 8 cascade in hepatocytes during Con A-induced liver failure have no impact on tissue injury. Additionally, STAT1 activation alone after Con A injection in liver cells does not result in liver damage. In contrast, IFN-gamma-dependent expression of IFN regulatory factor-1 and TNF-alpha-dependent activation of c-Jun N-terminal kinase in liver cells correlates with liver cell damage after Con A injection. Therefore, our experiments indicate that 11418690 PMID:11418690

Streetz, K; Fregien, B; Plümpe, J; Körber, K; Kubicka, S; Sass, G; Bischoff, S C; Manns, M P; Tiegs, G; Trautwein, C

2001-07-01

275

Methane activation by cobalt cluster cations, Co(n)+ (n = 2-16): reaction mechanisms and thermochemistry of cluster-CH(x) (x = 0-3) complexes.  

PubMed

The kinetic energy dependences of the reactions of Co(n)(+) (n = 2-16) with CD(4) are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. The main products are hydride formation, Co(n)D(+), dehydrogenation to form Co(n)CD(2)(+), and double dehydrogenation yielding Co(n)C(+). These primary products decompose to form secondary and higher order products, Co(n)CD(+), Co(n-1)D(+), Co(n-1)C(+), Co(n-1)CD(+), and Co(n-1)CD(2)(+) at higher energies. Adduct formation of Co(n)CD(4)(+) is also observed for the largest cluster cations, n > or = 10. In general, the efficiencies of the single and double dehydrogenation processes increase with cluster size, although the hexamer cation shows a reduced reactivity compared to its neighbors. All reactions exhibit thresholds, and cross sections for the various primary and secondary reactions are analyzed to yield reaction thresholds from which bond energies for cobalt cluster cations to D, C, CD, CD(2), and CD(3) are determined. The relative magnitudes of these bond energies are consistent with simple bond order considerations. Bond energies for larger clusters rapidly reach relatively constant values, which are used to estimate the chemisorption energies of the C, CD, CD(2), and CD(3) molecular fragments to cobalt surfaces. PMID:19206975

Citir, Murat; Liu, Fuyi; Armentrout, P B

2009-02-01

276

Ground-state magnetic properties of CoN clusters on Pd(111): Spin moments, orbital moments, and magnetic anisotropy  

NASA Astrophysics Data System (ADS)

The ground-state spin moments , orbital moments , and magnetic anisotropy energy (MAE) of CoN clusters deposited on the Pd(111) surface are determined in the framework of a self-consistent, real-space tight-binding method. Two-dimensional CoN/Pd(111) with N<~13 show remarkably large total magnetic moments per Co atom Mz=(2+)/N=(2.4 2.7)?B, which are the result of three physically distinct effects. The first and leading contribution comes, as expected, from the local spin moments at the Co atoms i=1-N [2Co?1.7?B]. Second, significant spin moments are induced at the Pd atoms i>N close to the Co-Pd interface, which amount to about 20% of Mz [2Pd=(0.2 0.3)?B]. Finally, remarkably enhanced orbital magnetic moments are found that are responsible for approximately 20% of Mz. In the case of Co atoms, Co?(0.3 0.5)?B is almost a factor of 3 larger than the Co-bulk orbital moment, while in Pd atoms Pd=(0.02 0.04)?B represents about 10% of the total local moment ?iz=2+. The dependence of the orbital moments on the orientation of the magnetization with respect to the cluster structure is quantified. These results and the associated MAEs are analyzed from a local point of view. One- and two-dimensional (2D) CoN are considered in order to investigate the structural dependence of the magnetic behavior. The role of the cluster-surface interactions is discussed by comparison with free cluster calculations. In particular, we observe that the lowest-energy magnetization direction (easy axis) changes from in-plane to off-plane upon deposition of 2D CoN on Pd(111). Cluster-substrate hybridizations are therefore crucial for the magnetoanisotropic behavior of magnetic islands deposited on metallic substrates.

Félix-Medina, R.; Dorantes-Dávila, J.; Pastor, G. M.

2003-03-01

277

[Intracranial hypertension related to sedation with sevoflurane using the AnaConDa(®) device in a patient with severe traumatic brain injury].  

PubMed

Sedation in neurocritical patients remains a challenge as there is no drug that meets all the requirements. Since the appearance of the AnaConDa(®) device, and according to the latest recommendations, sevoflurane has become an alternative for patients with brain injury. The use of AnaConDa(®) produces an increase in the anatomical dead space that leads to a decrease in alveolar ventilation. If the decrease in the alveolar ventilation is not offset by an increase in minute volume, there will be an increase in PaCO2. We report the case of a patient with severe traumatic brain injury who suffered an increase in intracranial pressure as a result of increased PaCO2 after starting sedation with the AnaConDa(®) device. PMID:22920835

Ferrando, C; Carbonell, J A; Aguilar, G; Badenes, R; Belda, F J

2013-10-01

278

Intraspecific alkaloid variation in ladybird eggs and its effects on con- and hetero-specific intraguild predators.  

PubMed

Egg predation and cannibalism are common phenomena in predatory ladybirds despite the presence of defensive alkaloids. Consumption of heterospecific eggs negatively affects survivorship and development; however, intraspecific variation in quantities of alkaloids and post-ingestion responses to con- and hetero-specific alkaloids, are not well understood. We examined variation in the quantity of alkaloids in eggs of Harmonia axyridis (Pallas), Coccinella septempunctata L., and Hippodamia convergens (Guérin) using gas chromatography-mass spectrometry, and show a link between heterospecific alkaloids and their toxicity and/or costs by feeding high and low alkaloid eggs to first instar H. axyridis and C. septempunctata. The repeatability of alkaloid measurements in eggs in an egg cluster was high; however, the amount of alkaloids varied significantly between egg clutches within and among females. This variation affected egg consumption by C. septempunctata when fed H. axyridis eggs. Harmonia axyridis accumulated their own alkaloid by cannibalism and synthesized it de novo, but C. septempunctata lost some portion of the consumed conspecific alkaloids. Both species lost most of the consumed heterospecific alkaloids, but C. septempunctata died within 3 days. Most H. axyridis survived to the second instar, but C. septempunctata alkaloids led to a significant reduction in weight gain compared to an aphid control. In addition, ingestion of high alkaloid C. septempunctata extended development of H. axyridis compared to the aphid control or conspecific eggs. Harmonia axyridis had greater abilities to process ingested con- and hetero-specific alkaloids compared with C. septempunctata, which may, in part, explain their interspecific interactions in nature. PMID:20049478

Kajita, Yukie; Obrycki, J J; Sloggett, J J; Haynes, K F

2010-06-01

279

Lectin from Canavalia brasiliensis (ConBr) protects hippocampal slices against glutamate neurotoxicity in a manner dependent of PI3K/Akt pathway.  

PubMed

The excitotoxicity induced by excessive activation of the glutamatergic neurotransmission pathway is involved in several neuropathologies. In this sense, molecules that prevent the release of glutamate or the excessive activation of its receptors can be useful in preventing the neuronal cell death observed in these diseases. Lectins are proteins capable of reversible binding to the carbohydrates in glycoconjugates, and some have been used in the study and purification of glutamate receptors. ConBr is a mannose/glucose-binding lectin purified from Canavalia brasiliensis seeds. In the present study, we aimed to evaluate the neuroprotective activity of ConBr against glutamate-induced excitotoxicity. Hippocampal slices were isolated from adult male mice and incubated for 6h in Krebs saline/DMEM buffer alone (control), in the presence of glutamate or glutamate plus ConBr. The phosphorylation of Akt and mitogen activated protein kinases (MAPKs) such as ERK1/2, p38(MAPK) and JNK1/2/3 was evaluated with western blotting. The results indicate that glutamate provoked a reduction in the hippocampal slice viability (-25%), diminished the phosphorylation of Akt and augmented p38(MAPK) and ERK1 phosphorylation. No changes were observed in the phosphorylation of JNK1/2/3 or ERK2. Notably, ConBr, through a mechanism dependent on carbohydrate interaction, prevented the reduction of cell viability and Akt phosphorylation induced by glutamate. Furthermore, in the presence of the PI3K inhibitor LY294002, ConBr was unable to reverse glutamate neurotoxicity. Taken together, our data suggest that the neuroprotective effect of ConBr against glutamate neurotoxicity requires oligosaccharide interaction and is dependent on the PI3K/Akt pathway. PMID:23454192

Jacques, Amanda V; Rieger, Débora K; Maestri, Mariana; Lopes, Mark W; Peres, Tanara V; Gonçalves, Filipe M; Pedro, Daniela Z; Tasca, Carla I; López, Manuela G; Egea, Javier; Nascimento, Kyria S; Cavada, Benildo S; Leal, Rodrigo B

2013-05-01

280

Elevated cyclic AMP suppresses ConA-induced MT1-MMP expression in MDA-MB-231 human breast cancer cells  

Microsoft Academic Search

We have previously reported that induction of MMP-2 activation by Concanavalin A (ConA) in MDA-MB-231human breast cancer cells\\u000a involves both transcriptional and post-transcriptional mechanisms, and that the continuous presence of ConA is required for\\u000a MMP-2 activation (Yu et al. Cancer Res, 55, 3272-7, 1995).In an effort to identify signal transduction pathways which may\\u000a either contribute to or modulate this mechanism,we

Ming Yu; Hiroshi Sato; Motoharu Seiki; Sarah Spiegel; Erik W. Thompson

1998-01-01

281

Aortic surface coat scanning electron-microscopic modifications after short-term hypercholesterolic diet, visualized in rabbits by con A-haemocyanin reaction.  

PubMed

Modifications of the aortic endothelial surface coat have been visualized at SEM with the use of the Con A-haemocyanin method. After fifteen days of an atherogenic diet, a strong increase of the reactive coat was evident in areas near the orifice of the collateral branches. In other areas, the reaction appeared to be intensely diminished. PMID:901615

Weber, G; Fabbrini, P; Resi, L; Toti, P

1977-06-01

282

Evaluación de estimadores no paramétricos de la riqueza de especies. Un ejemplo con aves en áreas verdes de la ciudad de Puebla, México  

Microsoft Academic Search

Nuestro objetivo fue evaluar el desempeño de estimadores no paramétricos de la riqueza de especies con datos reales. Durante la temporada de cría de 2003 censamos las comunidades de aves en dos áreas verdes de la ciudad de Puebla (México), y obtuvimos las corres¬pondientes curvas de rarefacción, que fueron ajustadas a dos funciones de acumulación de especies no asintóticas y

J. A. González Oreja; A. A. De la Fuente-Díaz-Ordaz; L. Hernández-Santín; D. Buzo-Franco; C. Bonache-Regidor

2010-01-01

283

BRIEF COMMUNICATIONS: Influence of collisions of the second kind on the electron energy balance and lasing characteristics of CON2 mixtures  

Microsoft Academic Search

A numerical solution of the Boltzmann transport equation for the electron energy distribution function and of a system of rate equations for the populations of the vibrational levels of the carbon monoxide and nitrogen molecules is used to study the influence of collisions of electrons with vibrationally excited molecules on the electron energy balance and characteristics of lasing of CO-N2

R. Sh Islamov; Yu B. Konev; Igor'V. Kochetov; A. K. Kurnosov

1984-01-01

284

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

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

Dinakaran, Paul M; Kalainathan, S

2013-07-01

285

Oxacilin-resistant Coagulase-negative staphylococci (CoNS) bacteremia in a general hospital at S?o Paulo city, Brasil  

PubMed Central

In the last decades, coagulase-negative staphylococci (CoNS), especially Staphylococcus epidermidis have become an important cause of bloodstream infections. In addition, rates of methicillin-resistance among CoNS have increased substantially, leading to the use of glicopeptides for therapy. The objective of this study was to evaluate eleven consecutives clinically relevant cases of oxacillin-resistant CoNS bacteremia in a general hospital localized in São Paulo city, Brazil. Five different species were identified by different phenotypic methods, including S. epidermidis (5), S. haemolyticus (3), S. hominis (1), S. warneri (1) and S. cohnii subsp urealyticus (1). A variety of Pulsed Field Gel Electrophoresis profiles was observed by macrorestriction DNA analysis in S. epidermidis isolates, but two of three S. haemolyticus isolates presented the same profile. These data indicated the heterogeneity of the CoNS isolates, suggesting that horizontal dissemination of these microorganisms in the investigated hospital was not frequent. One S. epidermidis and one S. haemolyticus isolates were resistant to teicoplanin and susceptible to vancomycin. The selective pressure due to the use of teicoplanin in this hospital is relevant.

d'Azevedo, P.A.; Secchi, C.; Antunes, A.L.S.; Sales, T.; Silva, F.M.; Tranchesi, R.; Pignatari, A.C.C.

2008-01-01

286

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

PubMed

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

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

2014-05-01

287

A Journal Pro/Con Forum: Why Third-Party Recruiters Do or Don't Fit in with Placement Services.  

ERIC Educational Resources Information Center

Presents opinions of two college placement officers and two representatives from business on third-party employment services. Discusses pros and cons. Includes a sample of a third-party job-vacancy announcement, a list of issues to explore when dealing with third-party recruiters, and two universities' notices to third-party employment services.…

Roberts, Jeff; And Others

1991-01-01

288

DETECCIÓN OPTOACÚSTICA DE NO2 CON EXCITACIÓN POR UN ARREGLO TRANSVERSAL DE LEDS AZULES NO2 OPTOACOUSTIC DETECTION BY TRANSVERSAL EXCITATION WITH AN ARRAY OF BLUE LEDS  

Microsoft Academic Search

Se desarrolló una celda simple de vidrio cerrada de forma cilíndrica, para aplicación en detección optoacústica, que es iluminada transversalmente con 32 LEDs azules distribuidos uniformemente a lo largo del tubo. Se forzó la excitación del segundo modo longitudinal iluminando en un semiciclo la zona central, comprendida entre los nodos de la onda estacionaria. Asimismo, durante el otro semiciclo, se

G. D. Santiago; A. L. Peuriot; F. González; V. B. Slezak; M. G. González

289

Fluoroalcohols induced unfolding of Succinylated Con A: native like beta-structure in partially folded intermediate and alpha-helix in molten globule like state.  

PubMed

Concanavalin A (Con A) exists in dimeric state at pH 5. In concentration range 20-60% (v/v) 2,2,2-trifluoroethanol (TFE) and 2-40% (v/v) 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), Con A at pH 5.0 shows visible aggregation. However, when succinyl Con A was used, no aggregation was observed in the entire concentration range of fluoroalcohols (0-90% v/v TFE and HFIP) and resulted in stable alpha-helix formation. Temperature-induced concentration-dependent aggregation in Con A was also found to be prevented/reduced in succinylated form. Possible role of electrostatic repulsion among residues in the prevention of hydrophobically driven aggregation has been discussed. Results indicate that succinylation of a protein resulted in greater stability (in both beta-sheet and alpha-helical forms) against alcohol-induced and temperature-induced concentration-dependent aggregation and this observation may play significant role in amyloid-forming proteins. Effect of TFE and HFIP on the conformation of a dimeric protein, Succinylated Con A, has been investigated by circular dichroism (CD), fluorescence emission spectroscopy, binding of hydrophobic dye ANS (8-anilinonaphthalene-1-sulfonic acid). Far UV-CD, a probe for secondary structure shows loss of native secondary structure in the presence of low concentration of both the alcohols, TFE (10% v/v) and HFIP (4% v/v). Upon addition of higher concentration of these alcohols, Succinylated Con A exhibited transformation from beta-sheet to alpha-helical structure. Intrinsic tryptophan fluorescence studies, ANS binding and near UV-CD experiments indicate the protein is more expanded, have more exposed hydrophobic surfaces and highly disrupted tertiary structure at 60% (v/v) TFE and 30% (v/v) HFIP concentrations. Taken together, these results it might be concluded that TFE and HFIP induce two intermediate states at their low and high concentrations in Succinyl Con A. PMID:16970906

Fatima, Sadaf; Ahmad, Basir; Khan, Rizwan Hasan

2006-10-15

290

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

PubMed Central

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.

Mann, Graham J; Thorne, Heather; Balleine, Rosemary L; Butow, Phyllis N; Clarke, Christine L; Edkins, Edward; Evans, Gerda M; Fereday, Sian; 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

291

V?4 ?? T cell-derived IL-17A negatively regulates NKT cell function in Con A-induced fulminant hepatitis.  

PubMed

Con A-induced fulminant hepatitis is a well-known animal model for acute liver failure. However, the role of ?? T cells in this model is undefined. In this report, using TCR ?(-/-) mice, we demonstrated a protective role of ?? T cells in Con A-induced hepatitis model. TCR ?(-/-) mice showed significantly decreased levels of IL-17A and IL-17F in the Con A-treated liver tissue, and reconstitution of TCR ?(-/-) mice with wild-type (Wt), but not IL-17A(-/-), ?? T cells significantly reduced hepatitis, strongly suggesting a critical role of IL-17A in mediating the protective effect of ?? T cells. Interestingly, only V?4, but not V?1, ?? T cells exerted such a protective effect. Furthermore, depletion of NKT cells in TCR ?(-/-) mice completely abolished hepatitis, and NKT cells from Con A-challenged liver tissues of TCR ?(-/-) mice expressed significantly higher amounts of proinflammatory cytokine IFN-? than those from Wt mice, indicating that ?? T cells protected hepatitis through targeting NKT cells. Finally, abnormal capacity of IFN-? production by NKT cells of TCR ?(-/-) mice could only be downregulated by transferring Wt, but not IL-17(-/-), V?4 ?? T cells, confirming an essential role of V?4-derived IL-17A in regulating the function of NKT cells. In summary, our report thus demonstrated a novel function of V?4 ?? T cells in mediating a protective effect against Con A-induced fulminant hepatitis through negatively regulating function of NKT cells in an IL-17A-dependent manner, and transferring V?4 ?? T cells may provide a novel therapeutic approach for this devastating liver disease. PMID:21987663

Zhao, Na; Hao, Jianlei; Ni, Yuanyuan; Luo, Wei; Liang, Ruifang; Cao, Guangchao; Zhao, Yapu; Wang, Puyue; Zhao, Liqing; Tian, Zhigang; Flavell, Richard; Hong, Zhangyong; Han, Jihong; Yao, Zhi; Wu, Zhenzhou; Yin, Zhinan

2011-11-15

292

The Temporal and Spatial Quantification of Holocene Sediment Dynamics for Reconstructing Soil Erosion: Pros, Cons and Challenges  

NASA Astrophysics Data System (ADS)

Since the early beginning of farming, humans have a strong impact on the landscape, on its land cover and therefore on the sediment dynamics. It is assumed that an increase of farming activity is documented by truncated soil profiles due to soil erosion on the slopes and deposition of the eroded material as colluvium and alluvium at foot-slope positions and in floodplains of rivers. In this respect, these sediment archives play a major role in reconstructing human induced soil erosion and in establishing catchment wide quantitative sediment budgets. However, the response of sediment archives to an external impact like the human impact on the landscape or climate events is not homogeneous within a catchment, but might be variable in time and space. This is well known and considered in the geomorphological concept of sediment cascade systems and therefore needs to be included as a basic idea in studies on past soil erosion and its driving factors, using sediment archives. However, the identification of representative sediment archives within a catchment and especially their temporal quantification is challenging. In this presentation I will discuss the importance of sediment archives for reconstruction past soil erosion, the significance of these archives for identifying possible causes of sediment redistribution and the pros, cons and challenges, which are involved.

Fuchs, Markus

2014-05-01

293

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

PubMed

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

Markert, Mathew; García, Luis René

2013-04-01

294

A review of safety, efficacy, pros and cons, and issues of puerperal tubal sterilization--an update.  

PubMed

This review focuses on the safety, efficacy, pros and cons of tubal sterilization procedures performed during the puerperium period while the woman is still in hospital. Findings from four previous reviews are synthesized, and the results published in more recent literature are evaluated. The review finds that tubal sterilization performed while the woman is still on the delivery table, or during a woman's early puerperium while she remains hospitalized, is operationally easy and medically safe, and does not adversely affect lactation. However, reported pregnancy rates are generally higher in puerperal tubal sterilization than in interval sterilization, especially when the mechanical tubal occlusion technique is used. The Pomeroy method, and its modifications via minilaparotomy, is highly recommendable. On the other hand, electrocoagulation via laparoscopy is associated with high efficacy, but a potentially increased risk of complications and difficulties in tubal reversal. Tubal sterilizations can be easily and safely performed at cesarean delivery in selected cases. Tubal sterilization performed during puerperium has a number of advantages over short-acting contraceptive methods, which require strict compliance, for postpartum use. However, candidates for puerperal tubal sterilization need to be carefully screened and counseled, since post-sterilization regret is more likely to occur. Unsettled issues for puerperal tubal sterilization and a number of practical problems that need to be addressed before initiation of a puerperal tubal sterilization program in a maternity clinic/hospital are discussed. PMID:8533623

Chi, I C; Petta, C A; McPheeters, M

1995-09-01

295

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

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

296

Special funding schemes for innovative medical devices in French hospitals: The pros and cons of two different approaches.  

PubMed

Financing innovative medical devices is an important challenge for national health policy makers, and a crucial issue for hospitals. However, when innovative medical devices are launched on the European market there is generally little clinical evidence regarding both efficacy and safety, both because of the flaws in the European system for regulating such devices, and because they are at an early stage of development. To manage the uncertainty surrounding the reimbursement of innovation, several European countries have set up temporary funding schemes to generate evidence about the effectiveness of devices. This article explores two different French approaches to funding innovative in-hospital devices and collecting supplementary data: the coverage with evidence development (CED) scheme introduced under Article L. 165-1-1 of the French Social Security Code; and national programs for hospital-based research. We discuss pros and cons of both approaches in the light of CED policies in Germany and the UK. The CED policies for devices share common limitations. Thus, transparency of CED processes should be enhanced and decisions need to be made in a timely way. Finally, we think that closer collaboration between manufacturers, health authorities and hospitals is essential to make CED policies more operational. PMID:24794738

Martelli, Nicolas; van den Brink, Hélène

2014-07-01

297

Supine percutaneous nephrolithotomy: con.  

PubMed

Advocates of supine percutaneous nephrolithotomy (PCNL) consider several theoretical advantages for this procedure. Despite the potential advantages of the supine PCNL, the majority of urologists have remained reluctant to perform this technique. This reluctance may be related to successful outcomes of prone PCNL and technical difficulties associated with supine PCNL. Feasibility of supine PCNL has been shown in different series and the current evidence, although limited and not fully organized, implies the application of this technique for patients with simple stones who are at high anesthesiological risk. However, there is no convincing evidence to support performing supine PCNL in morbidly obese patients and those with complex and multiple stones. Further randomized clinical trials of large sample size and high methodological quality are required to recommend extensive application of supine PCNL as an alternative to prone PCNL. PMID:22090043

Lashay, Alireza; Amini, Erfan; Ahanian, Ali; Ozhand, Ardalan; Nikkar, Mohammad Masoud; Sharifi, Seyed Hossein Hosseini

2011-01-01

298

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.

299

The Classics, Con Brio  

ERIC Educational Resources Information Center

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…

Hansen, James

1978-01-01

300

Circumcision: Pros and cons  

PubMed Central

Circumcision is possibly the most frequently performed elective surgical procedure in men. It can simply be described as the excision of the preputium. There have been several studies about the association between circumcision and urinary tract infections (UTI). Many studies have demonstrated that the frequency of UTI increase in uncircumcised males, especially in the first year of life. This review discusses the embryology of the preputium, epidemiology, indications, complications and benefits of circumcision, as well as operation and anesthesiology techniques. It especially examines the association between UTI and circumcision and the importance of circumcision in congenital urinary system anomalies. In addition, this review examines the associations between circumcision and sexually transmitted diseases, including HIV, and the protective role of circumcision on penile cancer.

Burgu, Berk; Aydogdu, Ozgu; Tangal, Semih; Soygur, Tarkan

2010-01-01

301

Neo-Conned University  

ERIC Educational Resources Information Center

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,…

Jones, Andee

2014-01-01

302

The Protective Effect of Intrasplenic Transplantation of Ad-IL-18BP/IL-4 Gene-Modified Fetal Hepatocytes on ConA-Induced Hepatitis in Mice  

PubMed Central

Background Concanavalin A (ConA)-induced hepatitis is an experimental murine model mirroring the pathology of human autoimmune hepatitis. Aim To investigate the effects of intrasplenically transplanted fetal hepatocytes (BNL.CL2) transfected with recombinant adenovirus vector expressing the IL-18 binding protein (IL-18BP) and IL-4 fusion protein on ConA-induced hepatitis in mice. Methods Ad-IL-18BP/IL-4 was used to infect BNL.CL2 cells. IL-4 and IL-18BP fusion protein expression were detected by ELISA and Western blotting. BNL.CL2 cells infected with Ad-IL-18BP/IL-4 were intrasplenically transplanted into mice. After 10 days, mice were injected with ConA (15 mg/kg), and sacrificed 18 hours later. Liver injury was assessed by serum transaminase and liver histology. TNF-?, IL-18, IL-4, IL-10, IL-12p70 and monocyte-chemoattracting protein (MCP)-1 levels in serum and liver homogenates were detected by ELISA. Signaling molecules in liver homogenates were analyzed by Western blotting. Results Ad-IL-18BP/IL-4 effectively expressed the IL-18BP/IL-4 fusion protein for more than 14 days in BNL.CL12 cells. Treatment of mice with Ad-IL-18BP/IL-4-BNL.CL2 before ConA injection significantly reduced the elevated plasma levels of transaminases compared with ConA control groups. TNF-?, IL-18, IL-12p70 and MCP-1 levels in serum and liver homogenates from mice transplanted with Ad-IL-18BP/IL-4-BNL.CL2 were lower and IL-4 and IL-10 levels were higher than control groups. Phosphorylation levels of NF-?B p65, AKT, p38 and JNK1/2 in liver homogenates were markedly suppressed by Ad-IL-18BP/IL-4. Conclusions Ad-IL-18BP/IL-4 was effectively transfected into mouse BNL.CL2 cells. Intrasplenic transplantation of Ad-IL-18BP/IL-4-BNL.CL12 cells alleviated the severity of inflammation in ConA-induced experimental hepatitis and provides a useful basis for the targeted gene therapy of liver disease.

Xu, Chenhuai; Hong, Bo; Xu, Wanhong; Shen, Ling; Jin, Changzhong; Wu, Zhigang; Tong, Xiangmin; Yao, Hangping

2013-01-01

303

Long-term fertility control in female cats with GonaCon™, a GnRH immunocontraceptive.  

PubMed

The uncontrolled reproduction of free-roaming feral cats contributes to overpopulation and associated concerns regarding their welfare and impact on public health and the environment. Nonsurgical fertility control that could be administered to feral cats in the field would be a powerful tool for cat population control. The objective was to test the efficacy and duration of activity of a single-dose GnRH immunocontraceptive vaccine (GonaCon™) on the fertility of adult female laboratory cats. Vaccinated cats (n = 15) received a single injection of vaccine containing a GnRH-KLH conjugate (200 ?g) emulsified in a mycobacterial and oil adjuvant on study Day 0. Sham-treated cats (n = 5) received a single injection containing all vaccine components except the GnRH-KLH conjugate. A breeding trial started on study Day 120. Vaccinated cats had a longer time to conception (median 39.7 mo) compared to sham-treated cats (4.4 mo; P < 0.001). A total of 93% of vaccinated cats remained infertile for the first year following vaccination, whereas 73, 53, and 40% were infertile for 2, 3, and 4 y, respectively. At study termination (5 y after a single GnRH vaccine was administered), four cats (27%) remained infertile. The GnRH antibody titers declined more rapidly in short-term responding cats with < 2 y of infertility (n = 4), compared to long-term responding cats that experienced fertility control for >2 y (n = 11) (P < 0.05). Non-painful but persistent late-onset granulomatous injection site masses appeared 2 y after initial vaccination in five cats. We concluded that GnRH immunocontraception is an ideal candidate for further development for feral cat control. PMID:21835455

Levy, Julie K; Friary, John A; Miller, Lowell A; Tucker, Sylvia J; Fagerstone, Kathleen A

2011-11-01

304

[Preliminary data on the different endothelial reaction to Con A at different levels of the arterial tree in rabbits and in Cynomolgus monkeys].  

PubMed

Delayed appearance of atherosclerotic lesions in cerebral arteries has been observed not only in man but also in monkeys and rabbits submitted to atherogenic diets. Previous observations of ours had shown a Con A positive reaction ("glycocalyx" or "surface coat") at the luminal surface and in the plasmalemmal vesicles of aortic endothelial cells of rabbits an other laboratory animals. The "surface coat" is now reputed the site of lipoproteinlipase activity whose importance in atherogenesis has recently been stressed. In our present observations, the endothelial cells Con A reactivity after Bernhard and Avrameas which was not previously studied in the cerebral arteries of rabbits and monkeys has resulted always lacking in this arterial district. Those observations may help explaining delayed appearance of atherosclerotic lesions in cerebral arteries. PMID:7337739

Weber, G; Fabbrini, P; Resi, L

1981-11-15

305

Optimization of an in vitro assay which measures the proliferation of duck T lymphocytes from peripheral blood in response to stimulation with PHA and ConA  

Microsoft Academic Search

The in vitro proliferative responses of duck PBMCs purified from Ficoll-Paqut: density gradients to the mitogens PHA and ConA show a great deal of duck-to-duck variation. Better responses were consistently obtained by using nylon wool fractionation to increase the proportion of duck T lymphocytes in PBMC preparations and then culturing these preparations with homologous monocytes, purified from PBMC preparations by

Edward M. Bertram; Allison R. Jilbert; Ieva Kotlarski

1997-01-01

306

A shock tube study of high temperature reaction of CON2OH2 mixtures and its application to CO2 gasdynamic laser  

Microsoft Academic Search

In order to investigate the gasdynamic laser (GDL), a conventional pressure-driven shock tube equipped with a nozzle apparatus was used. Kinetic study of CO2 formation in a CO-N2O-H2 system behind a reflected shock wave was carried out by measuring the 4.25 micron emission of CO2. Then, population inversions of the vibrational level of CO2 in an expanding flow of mixtures

H. Miyama; N. Fujii; N. Takeishi; T. Tokuda; N. Sakatsume

1989-01-01

307

Li storage and impedance spectroscopy studies on Co3O4, CoO, and CoN for Li-ion batteries.  

PubMed

The compounds, CoN, CoO, and Co3O4 were prepared in the form of nano-rod/particles and we investigated the Li-cycling properties, and their use as an anode material. The urea combustion method, nitridation, and carbothermal reduction methods were adopted to prepare Co3O4, CoN, and CoO, respectively. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and the Brunauer-Emmett-Teller (BET) surface and density methods were used to characterise the materials. Cyclic voltammetry (CV) was performed and galvanostatic cycling tests were also conducted up to 60-70 cycles. The observed reversible capacity of all compounds is of the increasing order CoO, Co3O4, CoN and all compounds showed negligible capacity fading. CoO allows for Li2O and Co metal to form during the discharge cycle, allowing for a high theoretical capacity of 715 mA h g(-1). Co3O4 allows for 4 Li2O and 3Co to form, and has a theoretical capacity of 890 mAhg(-1). CoN is the best anode material of the three because the nitrogen allows for Li3N and Co to form, resulting in an even higher theoretical capacity of 1100 mAhg(-1) due to the Li3N and Co metal formation. Irrespective of morphology the charge profiles of all three compounds showed a major plateaux ~2.0 V vs. Li and potential values are almost unchanged irrespective of crystal structure. Electrochemical impedance spectroscopy (EIS) was performed to understand variation resistance and capacitance values. PMID:24325322

Reddy, M V; Prithvi, Gundlapalli; Loh, Kian Ping; Chowdari, B V R

2014-01-01

308

A review of the practice of sedation with inhalational anaesthetics in the intensive care unit with the AnaConDa® device  

PubMed Central

The intensive care unit (ICU) environment is often perceived to be hostile and frightening by patients due to unfamiliar surroundings coupled with presence of numerous personnel, monitors and other equipments as well as a loss of perception of time. Mechanical ventilation and multiple painful procedures that often need to be carried out in these critically ill patients add to their overall anxiety. Sedation is therefore required not only to allay the stress and anxiety, but also to allow for mechanical ventilation and other invasive therapeutic and diagnostic procedures to be performed. The conventional intravenous sedative agents used in ICUs suffer from problems of over sedation, tachyphylaxis, drug accumulation, organ specific elimination and often lead to patient agitation on withdrawal. All this tend to prolong the ventilatory as well as ICU and hospital discharge time, which increase the risk for infection and add to the overall increase in morbidity, mortality and hospital costs. In 2005, the anaesthetic conserving device (AnaConDa®) was marketed for ICU sedation with volatile anaesthetic agents. A number of trials have shown the effectiveness of using volatile anaesthetic agents for ICU sedation with the AnaConDa device. Compared with intravenous sedatives, use of volatile anaesthetic agents have resulted in shorter wake up and extubation time, lesser duration of mechanical ventilation and faster discharge from hospitals. This review shall focus on the benefits, technical pre-requisites and status of sedation with volatile anaesthetic agents in ICUs with the AnaConDa® device.

Misra, Satyajeet; Koshy, Thomas

2012-01-01

309

Properties and structure of Yb 3+ doped zinc aluminum silicate phosphate glasses  

Microsoft Academic Search

This study explores a series of optical, thermal, and structural properties based on 60P2O5–30ZnO–10Al2O3 (60P) glasses that doped with varied rare earth (RE) elements Yb2O3 and P2O5 components replaced by SiO2. It was found that the glasses density decrease with SiO2 concentration added to replace P2O5, whereas they increase with increased concentration of Yb3+-doped. Moreover, the glasses transition temperature, softening

J. Y. Hu; H.-W. Yang; Y. J. Chen; J. S. Lin; C. H. Lai; Y. M. Lee; T. Zhang

2011-01-01

310

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

NASA Astrophysics Data System (ADS)

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.

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

311

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

312

In vitro and in vivo binding of snowdrop ( Galanthus nivalis agglutinin; GNA) and jackbean ( Canavalia ensiformis; Con A) lectins within tomato moth ( Lacanobia oleracea) larvae; mechanisms of insecticidal action  

Microsoft Academic Search

When fed in semi-artificial diet the lectins from snowdrop (Galanthus nivalis: GNA: mannose-specific) and jackbean (Canavalia ensiformis: Con A: specific for glucose and mannose) were shown to accumulate in vivo in the guts, malpighian tubules and haemolymph of Lacanobia oleracea (tomato moth) larvae. Con A, but not GNA, also accumulated in the fat bodies of lectin-fed larvae. The presence of

Elaine Fitches; Stephen D Woodhouse; John P Edwards; John A Gatehouse

2001-01-01

313

The beliefs about pros and cons of drinking and intention to change among hazardous and moderate alcohol users: a population-based cross-sectional study  

PubMed Central

Background: Fundamental to supporting hazardous alcohol users are the rationales for reducing alcohol intake highlighted by the users themselves. This study analyses the relative importance of beliefs about pros and cons of drinking in relation to having an intention to reduce intake among both hazardous and moderate alcohol users. Methods: Intention to change was assessed in a representative sample of Stockholm’s population (n = 4278, response rate 56.5%). Alcohol use was assessed using the Alcohol Use Disorders Identification Test measure. A decisional balance inventory was used to examine various beliefs about the pros and cons of drinking, which covered affect changes, social gains and losses, and possible adverse effects. Independent correlations were determined by logistic regression using a backward exclusion procedure (P > 0.05). Results: Higher ratings of importance were generally related to intent, whether or not the contrast was with having no intent or already having made a reduction. This was especially true for hazardous users. Only two beliefs were independently correlated with change among hazardous users: ‘Drinking could get me addicted’ and ‘Drinking makes me more relaxed/less tense’ (pseudo-R2 < 0.1). Among moderate users, there was no uniform pattern in the relationships. Conclusions: Unexpectedly, hazardous users with an intent to change rated pro arguments as more important than those with no intent to change. Of the investigated pros and cons, only a few were independently related to intention to change drinking behaviour. These arguments provide interesting topics in consultations. Little support was found for any rational decision making behind the intention to reduce alcohol intake.

Helgason, Asgeir R.; Ahacic, Kozma

2014-01-01

314

Sodium Tanshinone IIA Sulfonate Protects Mice From ConA-Induced Hepatitis via Inhibiting NF-?B and IFN-?\\/STAT1 Pathways  

Microsoft Academic Search

Introduction  Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIA, the main pharmacologically active component\\u000a of Salvia miltiorrhiza. The aim of this study was to investigate the effect of STS on concanavalin A (ConA)-induced hepatitis (CIH) in mice, an\\u000a experimental model of immune-mediated liver injury.\\u000a \\u000a \\u000a \\u000a Results  C57BL\\/6 mice pretreated with STS released much less alanine transaminase into plasma in

Yan Xu; Dechun Feng; Ying Wang; Shuting Lin; Lingyun Xu

2008-01-01

315

Deficiency of Con A-induced suppressor cell activity in peripheral blood mononuclear cells from Thai adults naturally infected with Plasmodium falciparum and Plasmodium vivax.  

PubMed

Con A-pretreated mononuclear (MNC) cells from Thai adults with naturally acquired P. falciparum or P. vivax malaria were significantly less effective in suppressing the responsiveness of autologous or normal allogeneic responder cells to mitogenic lectins or allogenic stimulator cells than pretreated cells from healthy donors. Serial studies of three patients demonstrated that reduced suppressor cell activity was present early in malaria infection but returned to normal soon after treatment. These studies demonstrate that the loss of T cells previously observed in patients with malaria, in part may functionally represent a loss of suppressor T cells. PMID:6226919

Gilbreath, M J; MacDermott, R P; Pavanand, K; Phisphumvithi, P; Kongchareon, S; Wimonwattrawatee, T

1983-09-01

316

Tissue factor expression in ovarian cancer: implications for immunotherapy with hI-con1, a factor VII-IgGF c chimeric protein targeting tissue factor  

Microsoft Academic Search

We evaluated the expression of tissue factor (TF) in ovarian cancer (EOC) and the potential of hI-con1, an antibody-like molecule\\u000a targeting TF, as a novel form of therapy against chemotherapy-resistant ovarian disease. We studied the expression of TF in\\u000a 88 EOC by immunohistochemistry (IHC) and real-time-PCR (qRT-PCR) and the levels of membrane-bound-complement-regulatory-proteins\\u000a CD46, CD55 and CD59 in primary EOC cell

Emiliano Cocco; Joyce Varughese; Natalia Buza; Stefania Bellone; Ken-Yu Lin; Marta Bellone; Paola Todeschini; Dan-Arin Silasi; Masoud Azodi; Peter E. Schwartz; Thomas J. Rutherford; Luisa Carrara; Renata Tassi; Sergio Pecorelli; Charles J. Lockwood; Alessandro D. Santin

317

40 CFR 60.201 - Definitions.  

Code of Federal Regulations, 2013 CFR

...or equivalent or alternative methods. (c) Equivalent P 2 O 5 feed means the quantity of phosphorus, expressed as phosphorus pentoxide, fed to the process. [40 FR 33154, Aug. 6, 1975, as amended at 65 FR 61757, Oct....

2013-07-01

318

40 CFR 60.211 - Definitions.  

Code of Federal Regulations, 2013 CFR

...or equivalent or alternative methods. (c) Equivalent P 2 O 5 feed means the quantity of phosphorus, expressed as phosphorus pentoxide, fed to the process. [40 FR 33155, Aug. 6, 1975, as amended at 65 FR 61757, Oct....

2013-07-01

319

40 CFR 60.241 - Definitions.  

Code of Federal Regulations, 2013 CFR

...or equivalent or alternative methods. (c) Equivalent P 2 O5 stored means the quantity of phosphorus, expressed as phosphorus pentoxide, being cured or stored in the affected facility. (d) Fresh granular triple...

2013-07-01

320

Guided ion-beam studies of the reactions of Co(n)+ (n=2-20) with O2: cobalt cluster-oxide and -dioxide bond energies.  

PubMed

The kinetic-energy dependence for the reactions of Co(n)+ (n=2-20) with O2 is measured as a function of kinetic energy over a range of 0 to 10 eV in a guided ion-beam tandem mass spectrometer. A variety of Co(m)+, Co(m)O+, and Co(m)O2+ (m < or = n) product ions is observed, with the dioxide cluster ions dominating the products for all larger clusters. Reaction efficiencies of Co(n)+ cations with O2 are near unity for all but the dimer. Bond dissociation energies for both cobalt cluster oxides and dioxides are derived from threshold analysis of the energy dependence of the endothermic reactions using several different methods. These values show little dependence on cluster size for clusters larger than three atoms. The trends in this thermochemistry and the stabilities of oxygenated cobalt clusters are discussed. The bond energies of Co(n)+-O for larger clusters are found to be very close to the value for desorption of atomic oxygen from bulk-phase cobalt. Rate constants for O2 chemisorption on the cationic clusters are compared with results from previous work on cationic, anionic, and neutral cobalt clusters. PMID:16122305

Liu, Fuyi; Li, Feng-Xia; Armentrout, P B

2005-08-01

321

A wireless, remote-query and high sensitivity Escherichia coli O157: H7 biosensor based on the recognition action of Con A  

PubMed Central

Escherichia coli O157: H7 is detected using a remote-query (wireless, passive) magnetoelastic sensor platform to which a 1 µm-thick layer of Bayhydrol 110 and then a layer of functionalized mannose is applied. The multivalent binding of lectin concanavalin A (Con A) to the E. coli surface O-antigen and mannose favors the strong adhesion of E. coli to the mannose modified magnetoelastic sensor; E. coli is rigidly and strongly attached on the mannose-modified sensor through Con A, which works as a bridge to bind to the E. coli surface O-antigen and mannose modified sensor surface. As E. coli is bound to the sensor its resonance frequency shifts, enabling quantification of E. coli concentration with a limit of detection of 60 cells/mL and a linear logarithmic response range of 6.0×101 to 6.1×109 cells/mL. The analysis can be directly conducted without incubation, and completed in 3 h or less.

Lu, Qingzhu; Lin, Hailan; Ge, Shutian; Luo, Shenglian; Cai, Qingyun; Grimes, Craig A.

2009-01-01

322

DETECTION OF GENETICALLY MODIFIED MAIZE FOOD PRODUCTS BY THE POLYMERASE CHAIN REACTION DETECCIÓN DE PRODUCTOS DE MAIZ GENETICAMENTE MODIFICADOS POR LA REACCIÓN EN CADENA DE LA POLIMERASA  

Microsoft Academic Search

A polymerase chain reaction (PCR) was applied to detect genetically modified (GM) maize and soybean food product, using specific 35S promoter primers for inserted chimerical genes in maize or soybean. The PCR detected food products that include ingredients obtained from GMOs in maize grains and flour, as well as processed in foods such as tortillas (Mexican crepe), corn chips, corn

A. Mendoza; S. Fernández; M. A. Cruz; M. A. Rodríguez-Perez; D. Resendez-Perez; H. A. Barrera Saldaña

2006-01-01

323

Research on Composite Silicate Dental Cements.  

National Technical Information Service (NTIS)

Conclusions are given regarding the frits of the system Ca3(PO4)2-A12O3-SiO2. The relationships in the quaternary system CaO-A12O3-SiO2-P2O5 are discussed. The cementing frits of the 10% P2O5 plane of this quaternary are presented. The compositions comple...

T. J. Rockett G. E. Maple

1968-01-01

324

A new model formulation of the SiO 2–Al 2O 3–B 2O 3–MgO–CaO–Na 2O–F glass-ceramics  

Microsoft Academic Search

Mono-phase glass-ceramics of akermanite were successfully produced from a Ca-mica and wollastonite via low-temperature sintering and crystallization. Doping with P2O5 considerably improves sintering behaviour since P2O5 increases the stability of glass against crystallization at the temperature of sintering onset. The resulting glass-ceramics feature good in vitro acceptance from osteoblasts, and moderate bioactivity due to the enrichment of the glassy phase

Simeon Agathopoulos; Dilshat U. Tulyaganov; Patricia Valério; José M. F. Ferreira

2005-01-01

325

Synsedimentary deformation of Pleistocene glaciolacustrine deposits in the Albese con Cassano Area (Southern Alps, Northern Italy), and possible implications for paleoseismicity  

NASA Astrophysics Data System (ADS)

We describe and interpret the well exposed soft-sediment deformations preserved in a Mid-Pleistocene proglacial sequence outcropping at Albese con Cassano, near Como (Southern Alps, N Italy). The observed deformations affect six distinct stratigraphic intervals within the same depositional sequence. The stratigraphy of this sequence, the geomorphic setting, and the careful geological mapping of the area clearly show that these deformations are not the result of glaciotectonics or cryoturbation, but are due to six separate events of synsedimentary liquefaction. In particular, the 3 basal deformed units include sand and gravel volcanoes that formed at the bottom of a proglacial lake. We examined several hypothesis of possible causative mechanism for the formation of these features. Taking into account all the information available on the local geology and sedimentary environment, it is possible to assess that the liquefaction features at Albese con Cassano had a coseismic origin. To our knowledge, this would be the first report of similar evidence of paleoseismicity in the Lombardia Southern Alps. Also, there is no record of historical liquefaction triggered by seismic events in an area of ca. 70 km of radius near Albese con Cassano, including the town of Como, the large metropolitan area of Milano and most of W Lombardia, that is one of the largest industrial districts in Europe. Therefore, the interpretation of the observed deformations can have critical impact for understanding the current seismicity level in the region, and mitigating the associated risk. In this paper we show that this interpretation is not a simple process. Liquefaction features must be treated with caution in order to derive suitable information for seismic hazard characterization, even if their coseismic origin has been definitely proved. It is necessary to understand the amount of seismic shaking (for instance, in terms of local macroseismic intensity) that can have produced that specific feature at that specific site, the location of the causative seismic event (epicenter and focal depth), and eventually its size (in terms of epicentral intensity and/or earthquake magnitude). In the case of Albese con Cassano, the implications in terms of seismic hazard of the observed possible earthquake paleoliquefactions can only be assessed through the definition of several scenarios, taking into account: a) different thresholds of shaking for triggering the described synsedimentary structures, and b) different seismotectonic frameworks related to the Mid-Pleistocene to Holocene evolution of the S Alps, including seismicity induced by isostatic glacial rebound. We conclude that it is worth checking these scenarios in the field with further paleoseismological research on other possible evidence of past earthquakes. There are no unequivocal sedimentological indicators of paleoseismicity, however, when carefully interpreted within the proper local seismotectonic context and compared with other earthquake-induced features, soft-sediment deformations can offer information of critical value for seismic hazard assessment.

Chunga, Kervin; Livio, Franz; Michetti, Alessandro M.; Serva, Leonello

2007-03-01

326

The role of intracellular high-mobility group box 1 in the early activation of Kupffer cells and the development of Con A-induced acute liver failure.  

PubMed

Acute liver failure (ALF) is a highly complex syndrome characterized by devastating activation of early activation of Kupffer cells (KCs) has been implicated in the pathogenesis of ALF. However, the factors regulating KC early activation are virtually unexplored. The aim of present study was to determine the role of the intracellular high-mobility group box 1 (HMGB1) in modulating the early activation of KCs during ALF. The intravenous injection of Concanavalin A (Con A) was used to establish a mouse model of ALF. The dynamic pro-inflammatory properties and MHC II expression of KCs were measured by qRT-PCR and flow cytometry. HMGB1 expression in KCs was measured by qRT-PCR and Western blotting. The immunofluorescence was implemented to determine the relocation of HMGB1 in KCs, and the siRNA against HMGB1 was utilized to assess the impact of HMGB1 on KC pro-inflammatory properties. The peak of pro-inflammatory cytokines production and MHC II expression in KCs appeared at the early stage of ALF. The up-regulation of HMGB1 expression and the translocation of HMGB1 in KCs were in parallel with the early activation of KCs. The blockade of intracellular HMGB1 expression caused by siRNA significantly inhibited the production of KC-derived pro-inflammatory cytokines, and led to a down-regulation of MAP kinase activation in KCs. The self-derived HMGB1 is an "early alarmin" of KC activation during Con A-induced ALF. HMGB1 might be a potential target for cell-specific strategy in ALF. PMID:23706499

Yang, Qiao; Liu, Yanning; Shi, Yu; Zheng, Min; He, Jiliang; Chen, Zhi

2013-10-01

327

Intracellular free zinc up-regulates IFN-? and T-bet essential for Th1 differentiation in Con-A stimulated HUT-78 cells  

PubMed Central

Zinc deficiency impairs cellular immunity. Up-regulation of mRNA levels of IFN-?, IL-12R?2, and T-bet are essential for Th1 differentiation. We hypothesized that zinc increases Th1 differentiation via up-regulation of IFN-? and T-bet expression. To test this hypothesis, we used zinc-deficient and zinc-sufficient HUT-78 cells (a Th0 cell line) under different condition of stimulation in this study. We also used TPEN, a zinc-specific chelator, to decrease the bioavailability of zinc in the cells. We measured intracellular free zinc, cytokines, and the mRNAs of T-bet, IFN-?, and IL-12R?2. In this study, we show that in zinc-sufficient HUT-78 cells (a Th0 cell line), mRNA levels of IFN-?, IL-12R?2, and T-bet in PMA/PHA-stimulated cells were increased in comparison to zinc-deficient cells. Although intracellular free zinc was increased slightly in PMA/PHA-stimulated cells, Con-A-stimulated cells in 5 ?M zinc medium showed a greater sustained increase in intracellular free zinc in comparison to cells incubated in 1 ?M zinc. The cells pre-incubated with TPEN showed decreased mRNA levels of IFN-? and T-bet mRNAs in comparison to cells without TPEN incubation. We conclude that stimulation of cells by Con-A via TCR, release intracellular free zinc which functions as a signal molecule for generation of IFN-? and T-bet, and IL-12Rb?2 mRNAs required for Th1 cell differentiation. These results suggest that zinc increase Th1 cell differentiation by up-regulation of IFN-? and T-bet, and IL-12Rb?2 mRNAs.

Bao, Bin; Prasad, Ananda S.; Beck, Frances WJ; Bao, Ginny W.; Singh, Tapinder; Ali, Shadan; Sarkar, Fazlul H.

2011-01-01

328

L'esperienza piemontese su oltre 200.000 gravidanze sottoposte a test di screening prenatale per la sindrome di Down dal 1990 al 2008: risultati con Tritest, Test integrato, Test combinato  

Microsoft Academic Search

Differenti marcatori e differenti associazioni di marcatori sono stati proposti dalla fine degli anni '80 per fornire un efficiente screening prenatale alle donne di tutte le età allo scopo di ottenere una stima più accurata del rischio individuale di sindrome di Down. In Piemonte i test di screening sono stati offerti dal 1990 con crescenti livelli di adesione. Le caratteristiche

Daniela C. Dall; Carla Bollati; Elisabetta Muccinelli; Franco Altare; Enza Pavanello; Varvara Guaraldo; Guglielmo Bracco; Annarita Filippo; Daniela Fortina; Elsa Viora; Simona Bastonero; Giuseppe Errante; Andrea Sciarrone; Marco Pagliano; Elena Gullino; Maria Grazia Alemanno; Simona Sdei; Roberto Scali; Pietro Gaglioti; Tullia Todros

329

¿CÓMO COMPITEN LAS PYMES EN LOS MERCADOS INTERNACIONALES? ANÁLISIS DE UN CLÚSTER LOCAL CON VOCACIÓN EXPORTADORA \\/ HOW DO SMEs COMPETE IN THE INTERNATIONAL MARKET? ANALYSIS OF AN EXPORT-ORIENTED LOCAL CLUSTER  

Microsoft Academic Search

Esta investigación trata de examinar si las empresas con distinto nivel de intensidad exportadora se diferencian respecto de los elementos competitivos que sustentan su competitividad en el mercado exterior, así como respecto de las estrategias de marketing que implementan en su actividad comercial internacional. Para ello, se examina una muestra de pymes pertenecientes a un clúster agroindustrial competitivo a nivel

David Jiménez Castillo; José Luis Ruiz Real; Manuel Sánchez Pérez

2012-01-01

330

Contenido de hierro y cinc en la semilla y su respuesta al nivel de fertilización con fósforo en 40 variedades de fríjol colombianas Seed iron and zinc content and their response to phosphorus fertilization in 40 Colombian bean varieties  

Microsoft Academic Search

El mejoramiento del fríjol en Colombia ha producido un amplio número de variedades para diferentes zonas agroecológicas y con diferentes rangos de adaptación. Los objetivos de esta investigación fueron determinar la calidad nutricional del fríjol en Colombia en cuanto al contenido de hierro y cinc en el grano y entender cómo los niveles de fertilización del suelo alta y baja

Carolina Astudillo; Matthew W. Blair

2008-01-01

331

Los estudios de las dietas alimenticias bajas en grasa, altas en fibra y ricas en frutas y vegetales no revelan efecto alguno en la formación de nuevos pólipos colorrectales en personas con antecedentes de pólipos precancerosos  

Cancer.gov

Dos nuevos estudios sobre el impacto nutricional en personas con alto riesgo de desarrollar cáncer colorrectal no mostraron evidencia de que la dieta afecta la formación de pólipos colorectales precancerosos (pólipos adenomatosos o adenomas) en personas a las que ya se les extrajo un pólipo.

332

ACTIVIDADES FORESTALES Y SU RELACIÓN CON EL SIG EN FORESTAL BOSQUES DEL PLATA S.A. FORESTRY ACTIVITIES AND THEY RELATIONSHIPS WITH THE GIS IN FORESTAL BOSQUES DEL PLATA S.A  

Microsoft Academic Search

Resumen El objetivo del presente trabajo es presentar las relaciones existentes entre algunas de las actividades forestales actualmente desarrolladas en Forestal Bosques del Plata S.A. y el sistema de información geográfica (SIG) vigente. Con el uso de nuevas tecnologías y capacitación del personal se han desarrollado proyectos de estudios de plantación establecida, instalación de parcelas permanentes, fichas de rodal y

R. Trujillo; R. Pezzutti; S. Schmidt; F. Rodríguez

333

Antiviral usage for H1N1 treatment: pros, cons and an argument for broader prescribing guidelines in the United States.  

PubMed

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

Goldstein, Edward; Lipsitch, Marc

2009-01-01

334

The pros and cons of routine central compartment neck dissection for clinically nodal negative (cN0) papillary thyroid cancer  

PubMed Central

Metastatic disease to regional lymph nodes (LNs) is common in papillary thyroid carcinoma (PTC). LN dissection is increasingly performed as part of the surgical management of PTC. The role of prophylactic central neck dissection (pCND) in PTC is unclear. There is limited evidence to support a routine pCND in clinical setting for nodal negative (cN0) PTC. The aim of this review was to examine the pros and cons of prophylactic neck dissection in cN0 PTC. In summary, the advantages of pCND are: removal of the central LNs that potentially harbor micro-metastases, more accurate staging of disease in order to plan more individualized management, reducing the need for re-operation to remove the metastatic LNs which have developed later and possible improvement in overall survival. The disadvantages are: an extensive surgery but lack of evidence of survival benefit, higher incidence of complications with little impact on local recurrence rate, possibility of over treating in cN0 patients and it does not sound like a cost effective approach in the management of small thyroid cancer. Considering low frequency of permanent morbidity, some authors believe that prophylactic neck dissection is safe in experienced hands even though its prognostic benefit has yet to be demonstrated.

Chan, Ai Chen; Wong, Kai Pun

2013-01-01

335

Entrenamiento con el traje espacial  

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...

336

Galaxias con núcleo doble. III  

NASA Astrophysics Data System (ADS)

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.

Gimeno, G.; Díaz, R. J.; Carranza, G.

337

Believing Others: Pros and Cons  

Microsoft Academic Search

In open environments there is no central control over agent behaviors. On the contrary, agents in such systems can be assumed to be primarily driven by self interests. Un- der the assumption that agents remain in the system for sig- nificant time periods, or that the agent composition changes only slowly, we have previously presented a prescriptive strategy for promoting

Sandip Sen; Anish Biswas; Sandip Debnath

2000-01-01

338

Cabergoline treatment in acromegaly: cons.  

PubMed

Many options are available for the treatment of acromegaly, including surgery, radiotherapy, and medical treatment. Cabergoline (CAB), a dopamine agonist with high affinity for dopamine receptor type 2, has been used both in monotherapy and in conjunction with somatostatin analogs (SSAs). Although it is administered orally and has a relatively lower-cost in comparison with SSAs, few studies have demonstrated its usefulness, there is a lack of randomized-controlled trials and other drugs (SSAs and pegvisomant) with more data in the literature are available; these issues are the main drawbacks of adopting CAB for the treatment of acromegaly. PMID:24504766

Kasuki, Leandro; Vieira Neto, Leonardo; Gadelha, Mônica R

2014-06-01

339

I-ConFIRM Membership  

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 Menu Search EGRP Site: EGRP Home About the Program Mission & Vision Organizational

340

A method for transforming a full computation of the effects of a complex-explosion scenario to a simple computation by ConWep  

NASA Astrophysics Data System (ADS)

When a large amount of explosive that is stored inside a structure explodes, a blast wave is generated. The strength of the blast depends on both the explosive (type and weight) and the properties of the storing structure, since part of the blast energy is needed to destroy the structure. If one is to determine the dynamic load (e.g., pressure and impulse) that is exerted by the blast on a neighboring structure, he needs to conduct a full numerical simulation with a validated numerical code. If the amount of the stored explosive changes while the storing structure remains the same a new full hydrodynamic computation is required. In the present study, we present a method by which, for a given structure inside which explosive is stored, only a few full hydrodynamic computations with different amounts of explosive are required in order to obtain the resulted blast wave load on a neighboring structure that is located at different distances from the exploding structure for any amount of explosive between the minimal and the maximal amounts that were used in the full hydrodynamic computations. By means of the proposed method, the problem, which as mentioned above needs a full hydrodynamic computation, is replaced by an equivalent problem of the explosion of a bare hemispherical charge. The equivalent problem can be solved by means of an empirical model such as ConWep, which is very simple to apply. The solution of the equivalent problem results in identical peak pressure and peak impulse at close and far ranges from the explosion source and very similar pressure and impulse profiles at far ranges. The proposed method is demonstrated by an explanatory example in which the effect of an explosion inside an ammunition magazine on the surroundings is studied.

Ostraich, B.; Sadot, O.; Levintant, O.; Anteby, I.; Ben-Dor, G.

2011-04-01

341

Efecto de la fertilización sobre la calidad de la papa para procesamiento en dos suelos antioqueños con propiedades ándicas Effects of fertilization on the industrial quality of potato in two antioquian Andisol soils  

Microsoft Academic Search

En este estudio se evaluó el efecto de tres niveles de NPK a la siembra (500, 1.500 y 3.000 kg·ha -1 ) en combinación con Ca (0, 2, 3 y 7 meq·100g -1 ), Mg (0; 0,7; 1,4 y 3,0 meq·100g -1 ), B (0; 0,5; 1,0 y 2,0 ppm) y S (0, 10, 20 y 40 ppm) sobre el

José M. Cotes

2008-01-01

342

Structural evolution of the Day Nui Con Voi metamorphic complex: Implications on the development of the Red River Shear Zone, Northern Vietnam  

NASA Astrophysics Data System (ADS)

The Day Nui Con Voi (DNCV) metamorphic complex in North Vietnam is the southernmost high-grade metamorphic zone along the NW-SE trending Red River Shear Zone (RRSZ) in Indochina. The RRSZ was considered as a classical large-scale continental strike-slip fault that had played a significant role in the continental extrusion of Southeast Asia since the collision of India and Eurasia. Earlier ideas determined the RRSZ as a steep shear zone that penetrated the entire lithosphere. Both metamorphism and structures within rocks along the DNCV metamorphic complex have been previously thought to be formed syn-tectonically by left-lateral shearing of the RRSZ during the Oligocene-Miocene continental escape tectonics. However, our meso- and microstructural re-examination of this region shows that these metamorphic rocks were formed during earlier tectonic episodes unrelated to strike-slip shearing. High angle to near orthogonal overprinting fabrics indicated that this region recorded three episodes of ductile deformation followed by brittle faulting events with different intensity spanning from the Triassic to the Tertiary. D 1 is preserved as NW-SE striking upright folds under garnet grade regional metamorphism during the Triassic Indosinian orogeny as South China block amalgamated with the Indochina block. The large-scale horizontal D 2 folds with a dominant top to N-NW bottom to S-SW sense of shear, and sub-horizontal fold axial planes suggest that the DNCV metamorphic complex remained at midcrustal depths since the Indosinian orogeny. The youngest ductile deformation event, D 3, refolded D 2 recumbent folds into a dome, and uplifted the DNCV as lower-temperature fabrics, S 3, indicated. Steep mylonite zones with left-lateral kinematic indicators and brittle faulting were developed on both limbs of the dome along the steep Song Hong and Song Chay faults during left-lateral movement of the RRSZ. Our new spatial, temporal and kinematic correlations of metamorphic fabrics within the DNCV metamorphic complex support the suggestion that the RRSZ developed after regional metamorphism and remained purely a crustal fault. The complicated deformation history recorded within the DNCV metamorphic complex provides an alternative interpretation and suggests that crustal scale strike-slip faults (such as the RRSZ) need not root from the mantle.

Yeh, Meng-Wan; Lee, Tung-Yi; Lo, Ching-Hua; Chung, Sun-Lin; Lan, Ching-Ying; Anh, Tran Tuan

2008-12-01

343

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)

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.

Huang, Wen-Cheng

2014-05-01

344

Guided ion-beam studies of the kinetic-energy-dependent reactions of Co(n)+ (n = 2-16) with D2: cobalt cluster-deuteride bond energies.  

PubMed

The kinetic-energy-dependent cross sections for the reactions of Co(n)+ (n = 2-16) with D2 are measured as a function of kinetic energy over a range of 0-8 eV in a guided ion-beam tandem mass spectrometer. The observed products are Co(n) D+ for all clusters and Co(n)D2+ for n = 4,5,9-16. Reactions for the formation of Co(n)D+ (n = 2-16) and Co9D2+ are observed to exhibit thresholds, whereas cross sections for the formation of Co(n)D2+ (n = 4,5,10-16) exhibit exothermic reaction behavior. The Co(n)+-D bond energies as a function of cluster size are derived from the threshold analysis of the kinetic-energy dependence of the endothermic reactions and are compared to previously determined metal-metal bond energies, D0(Co(n)+-Co). The bond energies of Co(n)+-D generally increase as the cluster size increases, and roughly parallel those for Co(n)+-Co for clusters n > or = 4. These trends are explained in terms of electronic and geometric structures for the Co(n)+ clusters. The bond energies of Co(n)+-D for larger clusters (n > or = 10) are found to be very close to the value for chemisorption of atomic hydrogen on bulk-phase cobalt. The rate constants for D2 chemisorption on the cationic clusters are compared with the results from previous work on cationic and neutral cobalt clusters. PMID:16161586

Liu, Fuyi; Armentrout, P B

2005-05-15

345

Deformation energies and mechanism during Vickers nanoindentation in lanthanum ultra- and metaphosphate glasses  

Microsoft Academic Search

Elastic and plastic deformation energies during Vickers nanoindentation (penetration depth ht=0.3–1.0 ?m) at room temperature (humidity 48%) of lanthanum phosphate glasses with different network structures (ultraphosphate 10La2O3·90P2O5 and metaphosphate 25La2O3·75P2O5 glasses (mol%)) were estimated. 10La2O3·90P2O5 glass has values of the Martens (universal) hardness MH=3.31±0.05 GPa, elastic recovery ER=0.60, elastic deformation energy Ue=130±5 kJ\\/mol and plastic deformation energy Up=88±5 kJ\\/mol at

K Narita; T Komatsu

2004-01-01

346

Anomalous fringe pattern of Ag colloid in phosphate glasses by implantation  

NASA Astrophysics Data System (ADS)

Ag ions of 150 keV were implanted into phosphate glasses at room temperature to doses of 0.1 to 60×10 16/cm 2. Depth profiles of Ag measured by Rutherford backscattering show both a surface peak and a bulk peak for doses ?10 16/cm 2. For MgO·P 2O 5 glass implanted with high dose, the surface peak for Ag and the optical band centered around 450 nm, the origin of which is considered to be Ag colloid, were observed at the fringe of the implantation area. These results suggest high diffusivity of Ag in the bulk and at the surface during implantation, resulting in the formation of Ag colloid at the fringe. For CaO·P 2O 5 and BaO·P 2O 5 glasses, similar depth profiles were obtained but the optical absorption caused by the ion beam appeared to be distinct.

Matsunami, Noriaki; Hosono, Hideo

1993-06-01

347

The effect of titanium and phosphorus on ferric/ferrous ratio in silicate melts: an experimental study  

NASA Astrophysics Data System (ADS)

The effect of TiO2 and P2O5 on the ferric/ferrous ratio in silicate melts was investigated in model silicate melts at air conditions in the temperature range 1,400-1,550 °C at 1-atm total pressure. The base composition of the anorthite-diopside eutectic composition was modified with 10 wt % Fe2O3 and variable amounts of TiO2 (up to 30 wt %) or P2O5 (up to 20 wt %). Some compositions also contained higher SiO2 concentrations to compare the role of SiO2, TiO2, and P2O5 on the Fe3+/Fe2+ ratio. The ferric/ferrous ratio in experimental glasses was analyzed using a wet chemical technique with colorimetric detection of ferrous iron. It is shown that at constant temperature, an increase in SiO2, TiO2, and P2O5 content results in a decrease in the ferric/ferrous ratio. The effects of TiO2 and SiO2 on the Fe3+/Fe2+ ratio was found to be almost identical. In contrast, adding P2O5 was found to decrease ferric/ferrous ratio much more effectively than adding silica. The results were compared with the predictions from the published empirical equations forecasting Fe3+/Fe2+ ratio. It was demonstrated that the effects of TiO2 are minor but that the effects of P2O5 should be included in models to better describe ferric/ferrous ratio in phosphorus-bearing silicate melts. Based on our observations, the determination of the prevailing fO2 in magmas from the Fe3+/Fe2+ ratio in natural glasses using empirical equations published so far is discussed critically.

Borisov, Alexander; Behrens, Harald; Holtz, Francois

2013-12-01

348

Investigation of the medium range structure of phosphosilicate glasses by cw-EPR, 1D-ESEEM and HYSCORE spectroscopies  

Microsoft Academic Search

6Li2O 3P2O5 6SiO2 and 6Na2O 3P2O5 6SiO2 glasses were exposed to 60Co ?-ray irradiation for the production of paramagnetic states that were studied by continuous wave(cw)-EPR, 1D-electron spin echo envelop modulation (ESEEM) and hyperfine sublevel correlation (HYSCORE) spectroscopies. The cw-EPR signal consisted of a doublet separated by ?47 G. This doublet was assigned to the Qn=2-type center (POHC-defect). The analysis

George Kordas

2001-01-01

349

Influence of B 2 O 3 on the structure and crystallization of soil active glasses  

Microsoft Academic Search

Glasses of the SiO2–P2O5–K2O–MgO–CaO–B2O3 system acting as nutrients carriers in the soil environment were synthesised by the melt-quenching technique. Thermal properties\\u000a were studied using DTA\\/DSC methods and the influence of B2O3 and P2O5 content on thermal stability and crystallization process of these glasses was examined. The structure of the glass network\\u000a was characterized by FTIR, 31P, and 11B MAS NMR.

Magdalena Szumera; Irena Wac?awska; Zbigniew Olejniczak

2010-01-01

350

Influence of the composition of ternary mixed solvent electrolytes on the properties of rechargeable lithium cells  

Microsoft Academic Search

A cell system consisting of an amorphous (a-)V2O5–P2O5 (95:5 in molar ratio) cathode, a lithium metal anode and an organic electrolyte by fabricating an AA-size prototype cell has been studied. The influence of the composition of ternary mixed solvent electrolytes comprising ethylene carbonate (EC), propylene carbonate (PC) and 2-methyltetrahydrofuran (2MeTHF) on the properties of AA-size Li\\/a-V2O5–P2O5 cells is examined. The

S.-I. Tobishima; K. Hayashi; Y. Nemoto; J.-I. Yamaki

1997-01-01

351

Aluminum lactate – An attractive precursor for sol–gel synthesis of alumina-based glasses  

Microsoft Academic Search

A novel aluminum precursor, aluminum lactate (Al(lact)3), was used in the sol–gel synthesis of alumina-based systems. The peculiar chelation properties of aluminum lactate in aqueous solution make this precursor quite attractive for the sol–gel synthesis of alumina-containing materials. Based on the reaction of aluminum lactate with different precursors such as phosphorus, boron, fluorine and others, (Na2O–)Al2O3–P2O5, (Na2O–)Al2O3–B2O3, (Na2O–)Al2O3–B2O3–P2O5, (Na–)Al–P–O–F, amorphous

Long Zhang; Carla C. de Araujo; Hellmut Eckert

2007-01-01

352

Sixfold coordinated Si in alkali and alkali-CaO silicophosphate glasses by Si Kedge XANES spectroscopy  

Microsoft Academic Search

Alkali and alkali?CaO silicophosphate glasses (R2O · 2SiO2 · 3P2O5 and ?R2O · ?CaO · 2SiO2 · 3P2O5; R ? Li, Na, K, Rb, Cs; ? = 0.5) have been investigated by Si K-edge X-ray absorption near-edge structure (XANES) spectroscopy for evidence of sixfold coordinated Si([6]Si) and its dependence on alkali metal cations. The XANES spectra were collected by fluorescence

M. E. Fleet; S. Muthupari; M. Kasrai; S. Prabakar

1997-01-01

353

MICROPROP AGAÇÃO DE DUAS ESPÉCIES FRUTÍFERAS, EM MEIO DE CULTURA DSD1, MODIFICADO COM FONTES DE BORO E ZINCO Micropropagation of two fruit tree species on dsd1 culture medium modified with boric acid and zinc sulfate  

Microsoft Academic Search

-1 ) e sulfato de zinco hidratado (0; 1,0; 2,0 e 4,0 mg L -1 ), em todas as combinações possíveis. Segmentos nodais de plantas preestabelecidas in vitro foram excisados e inoculados em tubo de ensaio, contendo 15 mL do meio de cultura. Posteriormente, os tubos de ensaio foram transferidos para sala de crescimento a 27 ± 1 º C,

Fabíola Villa; Moacir Pasqual; Franscinely Aparecida de Assis; Gleice Aparecida de Assis; Danielle Zampiere; Arce Zárraga

354

Pre-estudo da compatibilidade com sangue do PTFE copolimerizado com DMAA utilizando radiacao gama, PET e AFLON nao modificados. (Evaluation of the blood compatibility of PTFE grafted films with DMAA using gamma radiation).  

National Technical Information Service (NTIS)

The new method developed for Imai and Nose was to make use for evaluation of the blood compatibility of poly(tetrafluoroethylene) (PTFE) grafted films with N,N-dimethylacrylamide (DMAA). The amount of thrombus formed was measured gravimetrically at an app...

A. A. A. Queiroz O. Z. Higa

1990-01-01

355

EFECTO DE LA SINCRONIZACIÓN DEL ESTRO CON PROSTAGLANDINA-f2 VS CIDR + 500 UI DE eCG EN OVEJAS BERGAMACIA DURANTE EL INICIO DE LA FASE LUTEAL Effect of Estrus Synchronization with Prostaglandins-F2 Vs CIDR + 500 IU of eCG in Bergamacia Ewes During Early Luteal Phase  

Microsoft Academic Search

An experiment was conducted to investigate the effects of es- trous synchronization with PGF CIDR + 500 IU of eCG on interval to estrus, ovulation and steroidal hormones plasma concentrations during early luteal phase in sheep. Fourteen ewes were treated, distributed in two groups: Group 1 (Con- trol), synchronized with two injections of prostaglandin-F (PG), given 9 days apart, and

Luis Fernando Uribe-Velásquez; María Inés; Lênz Souza; Ana María; Loaiza Echeverri

356

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)

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.

Rivera Pacheco, Andres

357

Optimisation d'un procede de synthese de tri-n-butyle phosphate a partir de l'acide o-phosphorique. (The optimisation study of tbp synthesis process by phosphoric acid).  

National Technical Information Service (NTIS)

The present work deals with the optimisation study of TBP synthesis process by phosphoric acid. This way of synthesis is more advantageous than POCL3 or P2O5 as phosphatant agents. these latters are toxic and dangerous for the environnement. The optimisat...

A. Amedjkouh M. Attou A. Azzouz B. Zaoui

1995-01-01

358

Effect of Acid Gases on the Pigment Composition of the Leaves of Trees and Lawn Plants (Vliyanie Kislykh Gazov na Pigmentnyi Sostav Listev Drevesnykh i Gazonykh Rastenii).  

National Technical Information Service (NTIS)

The chlorophyll a and b, carotene, lutein, violaxanthin, and neoxanthin contents in the leaves of plants, subjected during various phases of their growth and development to acid gases such as SO2, NO2, F, HF, and P2O5 in various concentrations, were studi...

V. V. Suslova V. S. Nikoloevskii

1971-01-01

359

Increasing Fluosilicic Acid Evolution from Phosphate Rock by Digestion with Phosphoric Acid.  

National Technical Information Service (NTIS)

The Bureau of Mines has conducted research to develop processes or modifications to existing processes for increasing the recovery of fluorine from phosphate-rock. Preliminary batch-testing has shown that over 98 percent of the F and P2O5 in phosphate roc...

H. E. Blake B. D. Nash

1974-01-01

360

40 CFR 63.602 - Standards for existing sources.  

Code of Federal Regulations, 2010 CFR

...metric ton of equivalent P2 O5 feed (0.020 lb/ton). (b) Superphosphoric acid process line â(1) Vacuum evaporation process. On and after the date on which the performance test required to be conducted by §§ 63.7...

2010-07-01

361

40 CFR 63.602 - Standards for existing sources.  

Code of Federal Regulations, 2010 CFR

...metric ton of equivalent P2 O5 feed (0.020 lb/ton). (b) Superphosphoric acid process line â(1) Vacuum evaporation process. On and after the date on which the performance test required to be conducted by §§ 63.7...

2009-07-01

362

Shielding properties of lead and barium phosphate glasses  

NASA Astrophysics Data System (ADS)

P2O5-PbO-BaO glass system has been investigated to see its potential use as radiation shielding material by studying the effect of the content of each of its composing oxides. The results show that this glass system is suitable as radiation shielding material and has some advantages comparing to the existing commonly used radiation protection glasses.

Kharita, M. H.; Jabra, R.; Yousef, S.; Samaan, T.

2012-10-01

363

Properties of SiC-Whisker Reinforced Glass-Ceramic Composite for Biomedical Application.  

National Technical Information Service (NTIS)

SiC-whisker reinforced glass-ceramic in the system CaO-P2O5-SiO2 was fabricated by hot-pressing. Addition of SiC-whiskers (30 wt%) to the matric glass-ceramic increased flexural strength and fracture toughness up to 470 MPa and 4.2 MPa m(1/2) respectively...

O. Yanagisawa S. Ito

1988-01-01

364

40 CFR 60.214 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... P=Mp Rp where: Mp =total mass flow rate of phosphorus-bearing feed, Mg/hr (ton/hr). Rp =P2 O5...shall be used to determine the mass flow rate (Mp ) of the phosphorus-bearing feed. (ii) The Association of Official...

2013-07-01

365

40 CFR 60.234 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...equation: P = Mp Rp where: Mp total mass flow rate of phosphorus-bearing feed, Mg/hr (ton/hr). Rp =P2 O5...shall be used to determine the mass flow rate (Mp ) of the phosphorus-bearing feed. (ii) The Association of Official...

2013-07-01

366

40 CFR 60.224 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... P=Mp Rp where: Mp =total mass flow rate of phosphorus-bearing feed, Mg/hr (ton/hr). Rp =P2 O5...shall be used to determine the mass flow rate (Mp ) of the phosphorus-bearing feed. (ii) The Association of Official...

2013-07-01

367

40 CFR 60.204 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

... P=Mp Rp where: Mp =total mass flow rate of phosphorus-bearing feed, Mg/hr (ton/hr). Rp =P2 O5...shall be used to determine the mass flow rate (Mp ) of the phosphorus-bearing feed. (ii) The Association of Official...

2013-07-01

368

Competition between Medicago truncatula and wheat for 15N labeled soil nitrogen and influence of phosphorus  

Microsoft Academic Search

To determine competition for nitrogen uptake, a greenhouse experiment was conducted using annual Medicago truncatula cf. Jemalong (medic) and Triticum turgidum spp. durum cv. Karim (wheat) grown alone or in mixture, over five successive crop cycles. Pots were supplied with P equivalent to 0, 50, 100 and 150 kg P2O5 ha?1 at the beginning of each crop cycle. The soil

K. Elabbadi; M. Ismaili; L. A. Materon

1996-01-01

369

40 CFR 60.244 - Test methods and procedures.  

Code of Federal Regulations, 2013 CFR

...hr/Mg (lb/hr/ton) of equivalent P2 O5 stored. Csi =concentration of total fluorides from emission point âi...shall be used to determine the total fluorides concentration (Csi ) and volumetric flow rate (Qsdi ) of the effluent...

2013-07-01

370

Nanocomposite Prepared from In Situ Grafting of Polypyrrole to Aminobenzoyl-Functionalized Multiwalled Carbon Nanotube and Its Electrochemical Properties.  

National Technical Information Service (NTIS)

We reported the functionalization of multiwalled carbon nanotube (MWCNT) with 4-aminobenzoic acid by a 'direct' Friedel-Crafts acylation reaction in a mild polyphosphoric acid (PPA)/phosphorous pentoxide (P2O5) medium. The resulting 4- aminobenzoyl-functi...

H. Choi I. Jeon J. B. Baek L. Tan

2011-01-01

371

Communicating Genetic Risk: Pros, Cons, and Counsel  

Microsoft Academic Search

Shortly before his death in 1995, Kenneth B. Schwartz, a cancer patient at Massachusetts General Hospital (MGH), founded The Kenneth B. Schwartz Center at MGH. The Schwartz Center is a non-profit organization dedicated to supporting and advancing com- passionate health care delivery, which provides hope to the patient, support to caregivers, and encourages the healing process. The center sponsors the

RICHARD T. P ENSON; MICHAEL V. S EIDEN; KRISTEN M. SHANNON; MARCIE L. LUBRATOVICH; MARIA ROCHE; BRUCE A. CHABNER; THOMAS J. LYNCH; Schwartz Center Rounds

372

Hester Prynne as Role Model: Pro & Con.  

ERIC Educational Resources Information Center

McWalters denies DeSalvo's previous claim (see EJ 209 302) that "The Scarlet Letter" harms students through its message of repressed sexuality; he suggests that the book does not condemn sexuality. DeSalvo replies that "The Scarlet Letter" is presented to students in a harmful way; she again calls for the use of literature that celebrates…

McWalters, John B.; DeSalvo, Louise

1980-01-01

373

The pros and cons of phytoestrogens  

PubMed Central

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.

Patisaul, Heather B.; Jefferson, Wendy

2011-01-01

374

How they put the “con” in consulting  

Microsoft Academic Search

Takes a cynical but realistic look at some of the harsher realities of management consulting. Management consultants are experts at making a good impression and at selling their own services. However, this expertise is not always matched by the same level of technical skill. All too often, management consultants make suggestion for the sake of being seen to do something.

Brian Bloch

1999-01-01

375

Incentives for organ donation: pros and cons.  

PubMed

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

Chkhotua, A

2012-01-01

376

Roofing with Urethane: Pro and Con.  

ERIC Educational Resources Information Center

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)

Kinzer, Michael; Scott, Gerald P.E.

1981-01-01

377

Los premiados con el nobel de economía, \\  

Microsoft Academic Search

Como docente en economía quiero hacer un breve y atrevido comentario. a raíz del otorgamiento del Premio Nobel de Economía 1993 a los profesores Douglas C. North y Robert W. Fogel de las Universidades de Washington (Sant Louis) y Chicago respectivamente, por sus investigaciones en el área de la Historia Económica. La primera opinión expresada por el profesor Douglas al

Hugo Silva S

1994-01-01

378

Una “discussione in rete” con Stanley Wilder  

Microsoft Academic Search

On 4th January 2005 the USA Information Literacy community is shocked by the Stanley Wilder's article “Information Literacy Makes all the Wrong Assumptions” published on The Chronicle of Higher Education. The article strongly criticises against Information Literacy and academic libraries. As a reaction, an intense debate immediately arises within the USA Information Literacy community through the ILI-L discussion list. The

Basile Carla

2005-01-01

379

Trustless Grid Computing in ConCert  

Microsoft Academic Search

We believe that fundamental to the establishment of a grid computing framework where all (not just large organizations) are able to eectiv ely tap into the resources available on the global network is the establishment of trust between grid application developers and resource donors. Resource donors must be able to trust that their security, safety, and privacy policies will be

Bor-yuh Evan Chang; Karl Crary; Margaret Delap; Robert Harper; Jason Liszka; Tom Murphy Vii; Frank Pfenning

2002-01-01

380

Functional Grid Programming with ConCert  

Microsoft Academic Search

Grid computing has become increasingly popular with the growth of the Internet, especially in large-scale scientic computation. Computational Grids are characterized by their scale, their heterogeneity, and their unreliability, mak- ing the creation of Grid software quite a challenge. Security concerns make the deployment of Grid infrastructure simi- larly daunting. We argue that functional programming techniques, both well-known and new,

Tom Murphy VII

2004-01-01

381

ML grid programming with ConCert  

Microsoft Academic Search

Grid computing has become increasingly popular with the growth of the Internet, especially in large-scale scientific computation. Computational Grids are characterized by their scale, their hetero- geneity, and their unreliability, making the creation of Grid soft- ware quite a challenge. Security concerns make the deployment of Grid infrastructure similarly daunting. We argue that functional programming techniques, both well- known and

Tom Murphy Vii

2006-01-01

382

Pros, Cons to Dissolving Lung Clots  

MedlinePLUS

... busting drugs, said Giri, an assistant professor of clinical medicine at the University of Pennsylvania in Philadelphia. A ... Giri, M.D., M.P.H., assistant professor, clinical medicine, University of Pennsylvania, Philadelphia; Joshua Beckman, M.D., ...

383

Pros and Cons of Biological Control  

Microsoft Academic Search

This chapter will briefly review the positive aspects of biological control and will highlight a few examples. It will further\\u000a review negative aspects of biological control introductions. One of the examples where biological control led to detrimental\\u000a environmental effects was the introduction of the ladybeetle Harmonia axyridis, and this case will be outlined in more detail. This example will also

Dirk Babendreier

384

MADURACIÓN ÓSEA EN NIÑOS Y ADOLESCENTES CON  

Microsoft Academic Search

Objective: To evaluate bone maturation in obese children and to compare the findings from the Venezuelan atlas of bone maturation and the international atlas of Greulich.Pyle. Methods: The data of 30 obese children aged between 1 and 12 years, including weight, height, sex, chronological age, bone age and socioeconomic level were collected, in a cross-sectional study. To evaluate the bone

OBESIDAD Nolis Camacho-Camargo; Janett Velásquez-Guillén; Mariela Paoli-Valeri; Rosanna Cicchetti-Uzcátegui; Jorge Alvarado-Colmenares; Justo Santiago-Peña

385

McLuhan: Pro and Con.  

ERIC Educational Resources Information Center

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…

Rosenthal, Raymond, Ed.

386

The Big Con: China's Historical Sabotage  

ERIC Educational Resources Information Center

On June 4, 1989, the Chinese military, under orders from the highest levels of government, violently crushed peaceful civilian demonstrations in Beijing, most symbolically in and around Tiananmen Square. In the end, the Chinese government claimed that the death toll was approximately 200, but the Chinese Red Cross reported 2,000 to 3,000 deaths.…

Terrence Cheng

2009-01-01

387

Catálogo de galaxias con núcleo doble  

NASA Astrophysics Data System (ADS)

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.

Gimeno, G.; Díaz, R. J.; Carranza, G.

388

The Pros and Cons of Butterfly Barbells  

Microsoft Academic Search

During recent years butterfly barbells have been used actively as investment strategies. Such barbells are constructed in order to obtain a yield pick-up and at the same time to be risk neutral against a change in the slope of the yield curve and\\/or a parallel shift in the yield curve. However, empirically the yield curve may change in an unanticipated

Michael Christensen

2002-01-01

389

[Legalization of drugs--pro and con].  

PubMed

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

Marjanovi?-Cengi?, S

2001-01-01

390

[Centralization in obstetrics: pros and cons].  

PubMed

Possible advantages and disadvantages of a general centralization of German obstetric facilities are analysed in the study. The need for centralization of risk cases, especially premature births (regionalization) is pointed out. Centralization appears appropriate, since every fifth maternity unit in Germany (19.78%) has 300 or fewer deliveries per year. This one fifth of perinatal clinics accounts for 6.3% of all deliveries (N = 49450). There are appreciable differences between the old and new federal states (Bundesländer): in the recently acceded federal states, 48.7% of all perinatal clinics have deliveries of 300 and less per year. This group of perinatal clinics accounts for 29% of all deliveries in the new federal states. We have carried out a survey of the mother's attitude to centralization: out of 416 patients in the Detmold women's hospital whose mean age was 29.0 +/- 4.2 years, 90.4% were not in favor of general centralization of obstetrics. 43% were also against a centralization of risk cases (regionalization). 75% of the women surveyed objected to centralized obstetrics because of the 'possible absence of the family', the 'possible absence of students and trainees' (44.9%), the 'unfamiliarity with staff and premises' (41.8%) and 'fear of anonymity' (44.5%). The majority of all women (84.1%) did not want to have a drive more than 20 km to an obstetrics center. Fear of 'delivery in a taxi'(78.6%), the 'fear that the husband will come too late to the delivery' (65.4%) and that the 'overall course of the delivery might not be adequate for reasons of time'. The presence of a pediatrics department in conjunction with the perinatal clinic was rated very positively (93%). It is concluded from the data and further juridical considerations that centralization of risk cases (regionalization) is indispensable in the near future and that somewhat more further into the future decentralization should be carried out by closing obstetrics departments with substantially less than 350 deliveries per year. Attention is drawn to some consequences of such a structural reform which will probably have to be initiated by the German Association of Gynecologists and Obstetricians. PMID:8681127

Roemer, V M; Ramb, S

1996-01-01

391

The Pros and Cons of Petroleum Agreements.  

ERIC Educational Resources Information Center

A mineral agreements expert discusses the options open to tribes, from the most standard lease form to arrangements as yet untried by Indian Nations. Discussion covers 18 basic provisions for inclusion in agreements, tax considerations, and basic forms of petroleum agreements (leases, joint ventures, production sharing, and service contracts).…

Lipton, Charles J.

1980-01-01

392

Mujer con astenia: panarteritis nodosa microvascular  

Microsoft Academic Search

Según la Sociedad Española de Reumatología (SER) la incidencia de Panarteritis nodosa (PAN) microscópica es de 2 casos por millón de habitantes. Si hacemos cálculos en el total de la población española serían 92 casos. Es una patología no muy frecuente ni conocida. Presenta inicialmente síntomas generales inespecíficos (60-70 % de los casos), como fiebre, malestar, astenia, anorexia, pérdida de

Eva Pablos Herrero; Victòria Sabaté Cintas; Anna Fabra Noguera

2010-01-01

393

SPOTLIGHT: RON HALLDORSON, con't  

Microsoft Academic Search

band would play for shows and dances. Although Jack and the other band members promised to take good care of young Ron, the under-age musician admits to hearing lots of dirty jokes, which he thoroughly enjoyed With his father, being a fine musician himself, playing old time fiddle music, Ron was fortunate to be exposed to all the talent of

JAMES LANES

394

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 Menu Search EGRP Site: EGRP Home About the Program Mission & Vision Organizational

395

Nanoparticles: Health Effects--Pros and Cons  

PubMed Central

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.

Gwinn, Maureen R.; Vallyathan, Val

2006-01-01

396

Weighing the Pros and Cons of TAP  

ERIC Educational Resources Information Center

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…

Pieczura, Michelle

2012-01-01

397

Payment for donor kidneys: pros and cons.  

PubMed

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

Friedman, E A; Friedman, A L

2006-03-01

398

Polarimetría de estrellas con discos de ``escombros''  

NASA Astrophysics Data System (ADS)

We present optical polarimetric measurements of a set of ˜100 solar-type stars with and without debris disks. The selection of these objects were based on the presence of excesses in the spectral energy distributions. This sample is complemented with a group of stars from the northern hemisphere with similar characteristics. A statistical comparison of the stars with and without disk shows no significant differences in the observed polarizations. However, we identified a subset of objects (<10 % of the whole sample) with polarizations above the median that not follow the Law of Serkowsky. These polarizations might be due to the presence of disks. FULL TEXT IN SPANISH

García, L.; Gómez, M.

399

Open Admissions: The Pros and Cons.  

ERIC Educational Resources Information Center

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…

Barzun, Jacques; And Others

400

Endoscopist-Directed Propofol: Pros and Cons  

PubMed Central

Concerns about the safety of endoscopist-directed propofol (EDP) have been voiced that propofol should be given only by healthcare professionals trained in the administration of general anesthesia. Here we discuss the safety and drawbacks of EDP for routine endoscopic procedures. Currently, both diagnostic and therapeutic endoscopy are well tolerated and accepted by both patients and endoscopists due to the application of sedation in most clinics worldwide. Accordingly, propofol use is increasing in many countries. It is crucial for endoscopists to be very familiar with the use of propofol or a combination of drugs. However, the controversy regarding the administration of sedation by an endoscopist or an anesthesiologist continues. Until now, there have been no randomized control trials comparing sedation induced by propofol administered by an endoscopist or by an anesthesiologist. It might be difficult to perform this kind of study. For the convenience and safety of sedative endoscopy, it would be important that EDP be generally applied to endoscopic procedures, and for more safety, an anesthesiologist may automatically take care of particular patients at high risk of suffering from propofol side effects.

Kim, Eun Hye

2014-01-01

401

A "Con Law" Casualty or Victory?  

ERIC Educational Resources Information Center

The 11th Circuit Court upheld a Georgia district's termination of an exemplary teacher who refused an immediate drug test after a police dog sniffed out a marijuana cigarette in her unlocked car. This case illustrates application of zero-tolerance policies to teachers and other personnel despite employees' signed contracts. (MLH)

Zirkel, Perry A.

2001-01-01

402

VALUTAZIONE DEL METABOLISMO AZOTATO - UREA, ACIDO URICO ED ALLANTOINA URINARI - IN BOVINE DA LATTE ALIMENTATE CON DIETA A BASE DI INSILATO DI MAIS O FIENO (NOTA PRELIMINARE) EVALUATION OF NITROGEN METABOLISM - URINARY UREA, URIC ACID AND ALLANTOIN - ON LACTATING DAIRY COWS FED CORN SILAGE OR HAY BASED DIET (PRELIMINARY STUDY)  

Microsoft Academic Search

RIASSUNTO Scopo del lavoro è stato determinare l'effetto dell 'insilato di mais rispetto al fieno, come principal e componente della dieta, sul tenore azotato urinario. Secondo u n piano sperimentale a cross over 2x2, 14 bovine di razza Frisona (212±99 gg. lattazione e 26.7±5.9 kg latte\\/ d) sono state alimentate con due diete isoenergetic he, isoproteiche e isofibrose. Dopo tre

403

niVeLeS de ReSiStenCia a dRoGaS antitUbeRCULoSaS en PaCienteS Con CoinFeCCiÓn ViH \\/ tUbeRCULoSiS, LiMa, 1998-2001  

Microsoft Academic Search

ReSUMen Objetivos: Determinar los niveles de resistencia a drogas antituberculosas de primera línea en muestras clínicas de pacientesconcoinfecciónporelvirusdelainmunodeficienciahumanaytuberculosis?(VIH-TB)?encincohospitalesde? Lima en el periodo 1998-2000. Materiales y métodos: Estudio descriptivo que incluyó las muestras de cultivos de Mycobacterium tuberculosis de pacientes con coinfección VIH-TB, a los que se realizó las pruebas de sensibilidad por el método de las proporciones para isoniacida (H),

Luis Asencios S; Lucy Vásquez C; Elena Leo H; Neyda Quispe T; Luz Huaroto V; César Cabezas S

404

Determining the Origin of Phosphates in Lherzolitic Shergottites Through Phosphate Saturation Experiments  

NASA Astrophysics Data System (ADS)

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.

Calvin, C.; Rutherford, M.

2007-12-01

405

IMPACTO Y DETECCIÓN DE NIÑOS CON TRASTORNO POR DÉFICIT DE ATENCIÓN CON HIPERACTIVIDAD  

Microsoft Academic Search

The Attention Deficit Hyperactivity Disorder (ADHD) is a neurologic-based polygenetic disorder affecting some 3-6% of school-age children. Both its chronic character and its basic symptomathology (the attention deficit and the binomial hyperactivity-impulsiveness) have a large influence upon behaviour, academic performance and social relationships, which might lead to the development of associated disorders such as the Oppositional Defiant Disorder, the Conduct

Isabel Orjales Villar

406

Comment on the paper "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" by P.M. Dinakaran, S. Kalainathan [Spectrochim. Acta A 111 (2013) 123-130].  

PubMed

We argue that (trans)-4-chloro-4'-nitrostilbene is not a new organic nonlinear optical material as claimed by Dinakaran and Kalainathan [P.M. Dinakaran, S. Kalainathan, 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, Spectrochim. Acta A 111 (2013) 123-130], but instead a well-known compound whose synthesis, spectral data, single crystal structure and second harmonic generation (SHG) efficiency are well documented in the literature. The title paper is completely erroneous. PMID:24152596

Srinivasan, Bikshandarkoil R; Dhuri, Sunder N; Nadkarni, V S

2014-01-01

407

Cristallisation dans les verres de silicates contenant du molybdène et du phosphore  

NASA Astrophysics Data System (ADS)

L'ajout de certains oxydes dans un verre initialement homogène peut entraîner des cristallisations plus ou moins importantes du mélange lors de son refroidissement. Parmi les oxydes connus pour induire de tels phénomènes dans des verres de silicates, se trouvent l'oxyde de molybdène MoO{3} et l'oxyde de phosphore P{2}O{5}. Les matériaux étudiés ici sont des verres silico-sodo-calciques auxquels ont été ajoutés MoO{3} et P{2}O{5} en quantité variable, ce qui provoque des cristallisations importantes. L'identification et la quantification des phases cristallines en présence par MEB et méthode Rietveld à partir des diffractogrammes permettent de comprendre les rôles respectifs du molybdène et du phosphore dans les phénomènes de cristallisation intervenant dans ces verres. Mots-clés: verres d'oxydes, cristallisation, diffraction des rayons X

Cousi, C.; Bart, F.; Phalippou, J.

2004-11-01

408

Electronic polarizability of the oxide ion and density of binary silicate, borate and phosphate oxide glasses  

NASA Astrophysics Data System (ADS)

A relationship between the polarizability of the oxide ion ?O 2-( no), determined from the refractive index, and the experimental density has been established for binary oxide glasses, such as the systems of silicate, borate and phosphate. Our present conclusions suggest that the ?O 2-( no) values increase with increasing density. The increasing rate of ?O 2-( no) versus density depends strongly on the charge of metals in glasses. For binary glass systems, such as Bi 2O 3-SiO 2, Bi 2O 3-B 2O 3, Sb 2O 3-B 2O 3, Sb 2O 3-P 2O 5 and Bi 2O 3-P 2O 5, the increasing rate of ?O 2-( no) versus density is much larger (an order of magnitude ranging from one to two) than those of binary oxide glasses containing monovalent alkali and divalent metals.

Qi, Ji; Xue, Dongfeng; Ratajczak, Henryk; Ning, Guiling

2004-06-01

409

Enhanced Nonlinear Susceptibility in TeO2-BaO-SrO-Nb2O5 Tellurite Glasses  

NASA Astrophysics Data System (ADS)

We added systematically WO3 and P2O5 in a TeO2-BaO-SrO-Nb2O5 (TBSN) glass system, which are proposed for ultra-broadband Raman amplifiers. The response in nonlinear indices to this addition was studied and reported herewith. The third-order optical susceptibility (?3) measured using Maker fringe analysis increased with an increase in WO3 content and decreased with an increase in P2O5 content. When these components were added simultaneously, we observed that their ?3 reaches a value similar to that of pure TeO2 glass. In view of their higher Raman gain coefficient and amplification bandwidth and with the present result of higher nonlinear indices, these glasses are likely to be suitable for photonics applications.

Jose, Rajan; Qin, Guanshi; Arai, Yusuke; Ohishi, Yasutake

2007-07-01

410

A model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides using optical basicity  

NASA Astrophysics Data System (ADS)

A simple model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides was developed using optical basicity only. In this model, the temperature dependence of the rate constant can be described by the Arrhenius law, and the activation energy can be expressed with a linear function of the slag's optical basicity. The model was applied to some molten slag systems, such as FeO, FeO-CaO, FeO-SiO2, FeO-Na2O, FeO-CaO-SiO2, FeO-SiO2-P2O5, FeO-SiO2-Na2O, and FeO-CaO-SiO2-P2O5. A comparison between the predicted results and measured data showed that the model worked well.

Zhang, Teng; Hu, Xiao-jun; Shu, Qi-feng; Chou, Kuo-Chih

2012-08-01

411

Dependence of the critical cooling rate for lithium-silicate glass on nucleating agents  

NASA Technical Reports Server (NTRS)

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.

Huang, W.; Ray, C. S.; Day, D. E.

1986-01-01

412

A new model formulation of the SiO2-Al2O3-B2O3-MgO-CaO-Na2O-F glass-ceramics.  

PubMed

Mono-phase glass-ceramics of akermanite were successfully produced from a Ca-mica and wollastonite via low-temperature sintering and crystallization. Doping with P(2)O(5) considerably improves sintering behaviour since P(2)O(5) increases the stability of glass against crystallization at the temperature of sintering onset. The resulting glass-ceramics feature good in vitro acceptance from osteoblasts, and moderate bioactivity due to the enrichment of the glassy phase with Ca and Si. The good quality of the white colour at the surface and throughout the bulk, the matching of microhardness with tooth enamel, and the possibility to coat other biomaterials such as ZrO(2), Ti or hydroxyapatite make these materials promising for medical applications. PMID:15585227

Agathopoulos, Simeon; Tulyaganov, Dilshat U; Valério, Patricia; Ferreira, José M F

2005-05-01

413

The Structure of Germanium Niobium Oxide, an Inherently Non-Stoichiometric  

Microsoft Academic Search

Germanium niobium oxide, reported as GeO2.9Nb2O5, is inherently non-stoichiometric since it appears to be isostructural with P2O5.9Nb2O5. To fit this structure, there must be vacant oxygen sites or some sites accommodating 'interstitial' metal atoms, in relatively high concentration, and the mode of incorporating a stoichiometric excess of cations should cast some light on other niobium oxide type structures which have

J. S. Anderson; D. J. M. Bevan; A. K. Cheetham; R. B. von Dreele; J. L. Hutchison; J. Strahle

1975-01-01

414

Characterisation of antibacterial copper releasing degradable phosphate glass fibres  

Microsoft Academic Search

Phosphate-based glass fibres (PGF) of the general formula Na2O–CaO–P2O5 are degradable in an aqueous environment, and therefore can function as antibacterial delivery systems through the inclusion of ions such as copper. In this study, PGF with varying amounts of copper oxide (CuO) were developed for potential uses in wound healing applications. PGF with 0, 1, 5 and 10mol% CuO were

E. A. Abou Neel; I. Ahmed; J. Pratten; S. N. Nazhat; J. C. Knowles

2005-01-01

415

Bioactive borate glass scaffolds: in vitro and in vivo evaluation for use as a drug delivery system in the treatment of bone infection  

Microsoft Academic Search

The objective of this work was to evaluate borate bioactive glass scaffolds (with a composition in the system Na2O–K2O–MgO–CaO–B2O3–P2O5) as devices for the release of the drug Vancomycin in the treatment of bone infection. A solution of ammonium phosphate,\\u000a with or without dissolved Vancomycin, was used to bond borate glass particles into the shape of pellets. The in vitro degradation

Xin Liu; Zongping Xie; Changqing Zhang; Haobo Pan; Mohamed N. Rahaman; Xin Zhang; Qiang Fu; Wenhai Huang

2010-01-01

416

A new addition to the Phillipsite family of molecular sieves: A divalent metal-ion-framework substituted microporous aluminophosphate (DAF-8)  

NASA Astrophysics Data System (ADS)

By adding substantial amounts of either Co(II) or Zn(II) salts to a gel composed of Al 2O 3, P 2O 5 and the organic template 1,4-diaminocyclohexane, the tendency to yield layered aluminophosphates (AlPOs) is tilted in favour of the production of three-dimensional microporous MAlPOs: in particular, phase-pure samples of a novel Phillipsite structure (designated Davy-Faraday number 8, DAF-8) are formed.

Barrett, Philip A.; Sankar, Gopinathan; Stephenson, Richard; Catlow, C. Richard A.; Thomas, John Meurig; Jones, Richard H.; Teat, Simon J.

2006-03-01

417

A new addition to the Phillipsite family of molecular sieves: A divalent metal-ion-framework substituted microporous aluminophosphate (DAF-8)  

Microsoft Academic Search

By adding substantial amounts of either Co(II) or Zn(II) salts to a gel composed of Al2O3, P2O5 and the organic template 1,4-diaminocyclohexane, the tendency to yield layered aluminophosphates (AlPOs) is tilted in favour of the production of three-dimensional microporous MAlPOs: in particular, phase-pure samples of a novel Phillipsite structure (designated Davy–Faraday number 8, DAF-8) are formed.

Philip A. Barrett; Gopinathan Sankar; Richard Stephenson; C. Richard A. Catlow; John Meurig Thomas; Richard H. Jones; Simon J. Teat

2006-01-01

418

Electrochemical evaluation of multilayer silica–metacrylate hybrid sol–gel coatings containing bioactive particles on surgical grade stainless steel  

Microsoft Academic Search

Metallic materials are the most used materials as orthopaedic or dental implants because of their excellent mechanical properties. However they are not able to create a natural bonding with the mineralized bone and occasionally suffer localized corrosion. This work describes the electrochemical behaviour of a system of coatings with the addition of bioactive particles of the system SiO2–CaO–P2O5, that enhance

Josefina Ballarre; Damián A. López; Nataly C. Rosero; Alicia Durán; Mario Aparicio; Silvia M. Ceré

2008-01-01

419

Key factors controlling the size, biomass, and sprouting of Japanese alder swamp forest in Kushiro Mire, Hokkaido, Japan  

Microsoft Academic Search

The interrelation among size, biomass, and sprouting of alder trees was studied to extract the most important hydrochemistrical\\u000a factors controlling the growth of alder forest in Kushiro Mire, northern Japan. The gradient was mostly explained by chemical\\u000a variables such as pH, ash content, and P2O5, which showed strong positive correlation with each other, and secondarily by fluctuation of the water

Tomoko Negishi

2008-01-01

420

Sulfate content influencing methane production and emission from incubated soil and rice-planted soil in Northeast Thailand  

Microsoft Academic Search

This study was conducted using four soil treatments (0, 22.5, 45 and 90?mg??kg) with balanced amounts of nitrogen (N), phosphorus pentoxide (P2O5) and potassium oxide (K2O) for each treatment, provided using ammonium phosphate sulfate (42% of sulfate), rock phosphate, potassium chloride and urea. These treatments were employed in incubation and jar experiments to investigate methane (CH4) production, redox potential (Eh)

Sophoanrith Ro; Patcharee Seanjan; Thepparit Tulaphitak; Kazuyuki Inubushi

2011-01-01

421

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components  

NASA Technical Reports Server (NTRS)

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.

Campbell, J. E.

1973-01-01

422

Ternary and quaternary mixed electrolytes for lithium cells  

Microsoft Academic Search

This paper reports the influence of composition of mixed solvent electrolyte composition on the discharge capacity and charge–discharge cycle life of lithium metal\\/amorphous V2O5–P2O5 (95:5 in molar ratio) cells. The solvents used were ethylene carbonate (EC), propylene carbonate (PC), 2-methyltetrahydrofuran (2MeTHF) and THF. LiAsF6 was used as the solute. The electrolyte solutions examined here contain ternary and quaternary mixed systems.

S. I. Tobishima; K. Hayashi; Y. Nemoto; S. Sugihara; J. I. Yamaki

1999-01-01

423

Cycling performance and safety of rechargeable lithium cells with binary and ternary mixed solvent electrolytes  

Microsoft Academic Search

The influence of electrolyte composition on the cycling performance and safety of AA rechargeable cells with a lithium metal anode, and an amorphous (a-) V2O5-P2O5 cathode was examined. The cells were cycled at a discharge current of 1000 mA and a charging current of 200 mA. The electrolytes were composed of ethylene carbonate (EC)\\/2-methyltetrahydrofuran (2MeTHF) binary and EC\\/propylene carbonate (PC)\\/2MeTHF

S.-I. Tobishima; K. Hayashi; Y. Nemoto; J.-I. Yamaki

1999-01-01

424

Irradiation Resistance of Novel Scintillating Glass with SNO2 as Emission Center  

Microsoft Academic Search

In this paper, irradiation resistance of the novel scintillating phosphate glasses using SnO2 as emission center are reported for the first time. Host glass composition is 75P2O5-25SrO and different SnO2 concentrations are included. Irradiation treatments on glasses were carried out under the 60Co gamma-ray radiation with different dose. Results show that the transmittance of the glass samples decreased with the

Ce Shen; S. Baccaro; Yuwen Ou; Shufen Wang; Guorong Chen

2010-01-01

425

Temperature programmed reduction of the oxide form ofPNiMo\\/Al 2O 3 catalysts before and after water extraction  

Microsoft Academic Search

A series of co-impregnatedPNiMo\\/Al2O3 catalysts with phosphorus concentration varying from 0 to 13.6 wt% P2O5 was studied by temperature programmed reduction (TPR) in their oxidic state before and after water extraction. Diffuse reflectance (DRS) and infrared spectra (IR) of the samples after the water extraction procedure were also analyzed. The TPR data showed that the introduction of phosphorus in the

P. Atanasova; R. López Cordero; L. Mintchev; T. Halachev; A. López Agudo

1997-01-01

426

Effect of glass composition on the degradation properties and ion release characteristics of phosphate glass—polycaprolactone composites  

Microsoft Academic Search

A series of polycaprolactone and ternary-based (Na2O)0.55?x(CaO)x(P2O5)0.45 glass composites were created, each containing 20% volume percentage of glass with various calcium compositions. A short-term degradation study was carried out to investigate the physical and ion release behaviour of these composites, utilising analytical techniques such as dynamical mechanical analysis, and ion chromatography.All the composites experienced significant loss of weight and stiffness

Roopa L. Prabhakar; Steve Brocchini; Jonathan C. Knowles

2005-01-01

427

Ageing of pulsed-laser-deposited bioactive glass films  

Microsoft Academic Search

Bioactive glasses are osteoinductive biomaterials of great interest for medical applications as filler material in bone defects and as coating of implants.Bioactive glass thin films have been deposited on silicon plates by ArF laser ablation of silica-based glass targets (53% SiO2, 23% Na2O, 20% CaO, 4% P2O5). Ablation experiments have been carried out in vacuum (10?4mbar) and in a reactive

P González; J Serra; S Liste; S Chiussi; B León; M Pérez-Amor

2002-01-01

428

Effect of continuous application of manures and fertilizers on rhizosphere microflora in arecanut palm  

Microsoft Academic Search

Summary  The rhizosphere microflora of arecanut palm under continuous application of organic manures and inorganic fertilizers was\\u000a studied. The nutrients applied are 100 g N, 40 g P2O5 and 140 g K2O\\/palm\\/year in the form of organics and inorganics. The application of organic manure increased the microbial population.\\u000a The increase in microbial population was observed between the rhizosphere samples collected at

B. M. Bopaiah; N. T. Bhat

1981-01-01

429

Agricultural potential of anaerobically digested industrial orange waste with and without aerobic post-treatment  

Microsoft Academic Search

The potential of anaerobically digested orange waste with (AAD) and without (AD) aerobic post-treatment for use in agriculture was evaluated through chemical analyses, short-term phytotoxicity and long-term plant assays. Chemical analyses showed that AD contained ammonia and organic acids, and aerobic post-treatment did not significantly remove these phytotoxins. The N:P2O5:K2O ratio in AD was 1:0.26:0.96 and aerobic post-treatment did not

Prasad Kaparaju; Jukka Rintala; Aimo Oikari

2012-01-01

430

Bioactivity in glass\\/PMMA composites used as drug delivery system  

Microsoft Academic Search

Gentamicin sulfate has been incorporated in composites prepared from a SiO2–CaO–P2O5 bioactive glass and polymethylmethacrylate. Data showed that these materials could be used as drug delivery system, keeping the bioactive behavior of the glass. The composites supply high doses of the antibiotic during the first hours when they are soaked in simulated body fluid (SBF). Thereafter, a slower drug release

D. Arcos; C. V. Ragel; M. Vallet-Reg??

2001-01-01

431

Effect of melting temperature and time on iron valence and crystallization of iron phosphate glasses  

Microsoft Academic Search

The effect of melting temperature and time on iron valence, dissolution rate (DR) in deionized water, and crystallization of iron phosphate glasses was investigated using a 40Fe2O3–60P2O5, mol%, batch composition. The concentration of Fe2+ ions in these glasses increased from 17% to 57% as melting temperature increased from 1150°C to 1450°C, but remained nearly constant at about 20% for melting

C. S Ray; X Fang; M Karabulut; G. K Marasinghe; D. E Day

1999-01-01

432

Structural-electrical-optical properties relationship of sodium superionic conductor sputter-deposited coatings  

Microsoft Academic Search

Thin films of various compositions in the Na2O–SiO2–P2O5–ZrO2 system were deposited in glassy form by reactive magnetron sputtering. An analysis by spectrophotometry showed an increase of the extinction coefficient (k) with the amount of Fe contamination. This contamination, originating from parasitic plasmas, was suppressed when convenient protections were used. Therefore, it was possible to produce optical clear films. A structural

D. Horwat; J. F. Pierson; A. Billard

2008-01-01

433

Interaction of salinity, nitrogen, and phosphorus fertilization on wheat  

Microsoft Academic Search

This study determined whether the application of nitrogen (N) and phosphorus (P) could ameliorate salt?induced reduction in wheat production. Saline irrigation water (0.5, 4.0, 8.2, and 12.5 dS\\/m) and N and P fertilizers (150 kg N\\/ha and 37.5 kg P2O5\\/ha) were applied to wheat (Triticum aestivum L. ‘Saka 92') grown on a calcareous soil in a greenhouse experiment. Plants received

M. S. Soliman; H. G. Shalabi; W. F. Campbell

1994-01-01

434

A Sodium-Nitrate-Based, Water-Soluble, Granular Fertilizer for Sport Fish Ponds  

Microsoft Academic Search

We tested a granular, water-soluble, sodium-nitrate-based fertilizer (8% N, 24% P2O5, 15% K2O, and trace elements; per application rates of 8 and 16 kg\\/ha) for potential use in freshwater sport fish ponds and compared it with a liquid fertilization program commonly used in the United States. At 16 kg\\/ha application, the sodium-nitrate-based fertilizer was as effective as the liquid fertilizer

Yalcin Tepe; Claude E. Boyd

2001-01-01

435

Production of high-quality liquid fertilizers from wet-process acid via urea phosphate  

Microsoft Academic Search

A pilot-plant process is described that purifies wet-process phosphoric acid for the production of a high-quality urea-ammonium polyphosphate base solution. An intermediate product, crystalline urea phosphate, is produced from urea and merchant-grade (54% P2O5) wet-process phosphoric acid. The urea phosphate crystals contain only about 15 to 20% of the objectionable impurities (iron, aluminum, and magnesium) originally contained in the feed

C. A. Hodge; T. W. Motes

1994-01-01

436

Synthesis of Calcium Phosphates by PO(OH) x (OBut) 3?x and CaO 2 C 2 H 4  

Microsoft Academic Search

In this work, an alkoxide solution route to synthesize Ca phosphates was developed. For the precursors, a CaO2C2H4 solution was prepared by dissolving Ca metal powder into ethylene glycol, and a PO(OH)x(OBut)3-x solution was prepared by dissolving P2O5 inton -butanol under reflux conditions. In order to obtain a mixed solution of the two precursors, acetic acid was used as an

Wenjian Weng; J. L. Baptista

1997-01-01

437

Comparative Responses of Borago officinalis and Echium vulgare to Different Nitrogen and Phosphorus Sources  

Microsoft Academic Search

The effect of organic and mineral nitrogen, phosphorus, and bio-fertilizers on growth, yield, and fixed oil content of borage (Borago officinalis L.) and viper's bugloss (Echium vulgare L.) plants were studied in two field experiments. Nitrogen as ammonium nitrate at 0.75 and 110 kg N hectare; phosphorus as calcium super-phosphate at 50 and 75 kg P2O5 hectare; compost at 1.32

S. F. Hendawy; S. El-Gengaihi

2010-01-01

438

Evaluation of the Capacity of Phosphate Solubilizing Bacteria and Fungi on Different Forms of Phosphorus in Liquid Culture  

Microsoft Academic Search

In the present study, the capacity of phosphate solubilizing bacterial strain, Bacillus (FS3) and fungal isolates, Aspergillus FS9 and FS11 have been tested in National Botanical Research Institutes Phosphate nutrient medium (NBRIP) broths containing two different phosphate sources, Ca3(PO4)2 and rock phosphate (18% of total P2O5 and CaO 42.2%, of which 27 of P was soluble in 2% citric acid)

Metin Turan; Nizamettin Atao?lu; Fikrettin ?ah?n

2006-01-01

439

PHOSPHORUS PENTOXIDE-MONTMORILLONITE K-10 AS CATALYST FOR THE PREPARATION OF 1,1-DIACETATES UNDER SOLVENT-FREE CONDITIONS  

Microsoft Academic Search

A facile and efficient method for the preparation of 1,1-diacetates of aldehydes is improved. P2O5\\/montmorillonite K10 catalyzed 1,1-diacetates formation from aldehydes in dry media. Both aromatic and aliphatic aldehydes gave high yields (70–95%) of the corresponding 1,1-diacetates. Advantages of this method are the use of an inexpensive and selective catalyst, with high yields in simple operation and short reaction time

Hossein Eshghi; Zinat Gordi

2004-01-01

440

Multinuclear and multi-dimensional nuclear magnetic resonance investigation of silver iodide-silver phosphate fast ion conducting glasses  

Microsoft Academic Search

The results of a multi-nuclear nuclear magnetic resonance (NMR) study of (AgI)x(Ag2O)y(P2O5)1 ? x ? y glasses are reported. Using the two-dimensional variable-angle correlation spectroscopy experiment, the isotropic and anisotropic chemical shift interactions of phosphorus were determined as a function of silver iodide and silver oxide composition. From these measurements we determine the average conformation of the phosphate groups. In

K. K. Olsen; J. W. Zwanziger

1995-01-01

441

Preparation and bioactivity of sol-gel macroporous bioactive glass  

Microsoft Academic Search

Bioactive glass is well known for its ability of bone regeneration, and sol-gel bioactive glass has many advantages compared with melt-derived bioactive glass. 3-D scaffold prepared by the sol-gel method is a promising substrate material for bone tissue engineering and large-scale bone repair. Porous sol-gel glass in the CaO-SiO2-P2O5 system with macropores larger than 100 ?m was prepared by the

Zhihua Zhou; Jianming Ruan; Jianpeng Zou; Zhongcheng Zhou

2008-01-01

442

Biomimetic formation of apatite on the surface of porous gelatin\\/bioactive glass nanocomposite scaffolds  

Microsoft Academic Search

There have been several attempts to combine bioactive glasses (BaGs) with biodegradable polymers to create a scaffold material with excellent biocompatibility, bioactivity, biodegradability and toughness. In the present study, the nanocomposite scaffolds with compositions based on gelatin (Gel) and BaG nanoparticles in the ternary SiO2–CaO–P2O5 system were prepared. In vitro evaluations of the nanocomposite scaffolds were performed, and for investigating

Masoud Mozafari; Mohammad Rabiee; Mahmoud Azami; Saied Maleknia

2010-01-01

443

Preliminary Assessment of the Philips PW 1270 Multi-Channel X-Ray Spectrometer for the Analysis of Oxide Materials.  

National Technical Information Service (NTIS)

The performance of the Philips PW 1270 for the analysis of Fe (sub T), MnO, V2O5, TiO2, CaO, P2O5, SiO2, Al2O3 and MgO in oxide materials at different flux: sample ratios has been assessed. It has been established that, using a chromium target X-ray tube,...

A. Tunney

1974-01-01

444

High Temperature - High Energy Cell with a Solid Electrolyte.  

National Technical Information Service (NTIS)

High temperature energy cells for peak load equalizing stations and electric driven vehicles are studied. In the phase diagram with the end compounds Na2O, ZrO2, SiO2, P2O