Sample records for ENLACES QUIMICOS (chemical bonds)
from WorldWideScience.org

Sample records 1 - 20 shown. Select sample records:



1

ALGUNOS CONCEPTOS SOBRE NITRURO DE TITANIO Y EL CARBURO DE TITANIO/ SOME CONCEPTS ABOUT TITANIUM NITRIDE AND TITANIUM CARBIDE

RESTREPO PARRA, ELISABETH; ARANGO ARANGO, PEDRO JOSE; CASANOVA TRUJILLO, SIMEÓN
2009-06-01

Resumen en español En este artículo se presentan algunas características estructurales y químicas de materiales utilizados comúnmente en aplicaciones industriales como nitruro de titanio (TiN) y carburo de titanio (TiC). El análisis inicial se llevó a cabo a partir de los diagramas de fase del TiN y el TiC. En ellos se observan propiedades importantes como punto de fusión, punto de evaporación, polimorfismo y solubilidad entre otros. La comprensión de estos diagramas de fase lleva (mas) a un mejor entendimiento de las características de estos materiales. Por otro lado se hizo una evaluación de los enlaces químicos que resultan en la formación de las moléculas del TiN y TiC, teniendo en cuenta que en estos compuestos se presenta una combinación de enlaces iónico, covalente y metálico, lo que les otorga excelentes propiedades eléctricas mecánicas y tribológicas. Además, se consideró la hibridación que se produce para conseguir compuestos estables. Resumen en inglés In this work a sumary of structural and chemical characteristics of materials commonly employed in industrial applications such as TiN and TiC was realized. The analysis was realized from the phase diagrams of TiN and TiC. This materials present, important characteristics such as melting point, boiling point, polymorphism and solubility among others, are observed. These phase diagrams carry to a best understanding to the material properties. On the other hand, an analysis (mas) of chemical bonds that result in the TiN and TiC molecules formation, having into a count that they present ionic, covalent and metallic molecular combination bonds was carried out. Moreover, the hybridization that is produced in order to get stable compounds was considered.

Scientific Electronic Library Online (Spanish)

2

Zr-metal adhesion on graphenic nanostructures

Sánchez-Paisal, Yon ; Sánchez-Portal, Daniel ; Garmendia, N. ; Muñoz, R. ; Obieta, I. ; Arbiol, J. ; Calvo-Barrio, L.

3 pages, 3 figures.-- PACS nrs.: 68.35.Np, 61.46.Fg, 61.46.Df. | Our high resolution transmission electronic microscopy studies of multiwall carbon nanotubes show, after the growth of zirconia nanoparticles by a hydrothermal route, the presence of surface Zr, forming an atomically thin layer. Using ...

DRIVER (Spanish)

3

Zr-metal adhesion on graphenic nanostructures

Sánchez-Paisal, Yon; Sánchez-Portal, Daniel; Garmendia, N.; Muñoz, R.; Obieta, I.; Arbiol, J.; Calvo-Barrio, L.; Ayuela, Andrés
2008-08-04

Digital.CSIC (Spain)

4

Vibrational fingerprint of the structural tuning in push-pull organic chromophores with quinoid or proaromatic spacers.

Casado, Juan; Moreno Oliva, María; Ruiz Delgado, M. Carmen; Lopez Navarrete, Juan T.; Sanchez, Luis; Matin, Nazario; Andreu, Raquel; Carrasquer, Laura; Garin, Javier; Orduna, Jesús
2007-02-15

Digital.CSIC (Spain)

5

Tri-[Pt2Tl]3- and polynuclear chain [Pt−Tl]∞- Complexes based on nonbridged PtII−TlI bonds: Solid state and frozen solution photophysical properties

Falvello, Larry R.; Forniés, Juan; Garde, Raquel; García, Ana; Lalinde, Elena; Moreno, M. Teresa; Steiner, Alexander; Tomás, Milagros; Usón, Isabel
2006-02-01

Digital.CSIC (Spain)

6

Tracking the effects of rigidity percolation down to the liquid state: relaxational dynamics of binary chalcogen melts

Bermejo, Francisco Javier; Cabrillo García, Carlos; Bychkov, E.; Fouquet, P.; Ehlers, G.; Häussler, W.; Price, D.L.; Saboungi, Marie Louise
2008-06-20

Digital.CSIC (Spain)

7

Thermal decomposition and X-ray diffraction of sulphate efflorescent minerals from El Jaroso Ravine, Sierra Almagrera, Spain

Frost, Ray L.; Wain, Daria; Martens, Wayde N.; Locke, Ashley C.; Martínez-Frías, Jesús; Rull, Fernando
2007-05-22

Digital.CSIC (Spain)

8

Thermal X-ray Diffraction Study of Chaorite from Russia

Matesanz, Emilio; García Guinea, Javier; Crespo Feo, Elena; López-Arce, Paula; Valle Fuentes, Francisco José; Correcher, Virgilio
2008-01-01

Digital.CSIC (Spain)

9

The van der Waals potential energy surfaces and structures of He–ICl and Ne–ICl clusters

Prosmiti, Rita; Cunha, Carlos; Villarreal, Pablo; Delgado Barrio, Gerardo
2002-10-15

Digital.CSIC (Spain)

10

The stereochemistry of a rearrangement and fragmentation reaction of ring D of 13-hydroxygibberellins

Collado, Isidro G.; M. Fraga, Braulio; Hanson, James R.; Hitchcock, Peter B.; García-Tellado, Fernando
1988-01-01

Digital.CSIC (Spain)

14

The chemical and microbiological preparation of 15-oxo-Gibberellin derivatives

Fraga, Braulio M.; González, Pedro; Guillermo, Ricardo; Hernández, Melchor G.; Perales, Áurea
1995-01-01

Digital.CSIC (Spain)

17

Tetralkylammonium permanganate epoxidation of an uncreactive double bond by an intramolecular oxygen-atom transfer process

Robles Caycho, Juana; García-Tellado, Fernando; De Armas, Pedro; Marrero-Tellado, José Juan
1998-01-01

Digital.CSIC (Spain)

19

Systematic investigation of the structure of the Si(553)-Au surface from first principles

Riikonen, Sampsa ; Sánchez-Portal, Daniel

15 pages, 16 figures.-- PACS nrs.: 73.20.At, 71.15.Mb, 79.60.Jv, 68.35.B-.-- ArXiv pre-print available at: http://arxiv.org/abs/0712.1735 | We present here a comprehensive search for the structure of the Si(553)-Au reconstruction. More than 200 different trial structures have been studied using firs...

DRIVER (Spanish)

21

Synthesis of phytuberin. 4-endo-tet acid-catalyzed cyclization of alpha-hydroxy epoxides

Prangé, Thierry; Rodríguez Morales, María S.; Suárez, Ernesto
2003-05-01

Digital.CSIC (Spain)

23

Synthesis and use of deuterated palmitic acids to decipher the cryptoregiochemistry of a Δ(13) desaturation

Abad, José Luis; Serra, Montserrat; Camps Díez, Francisco; Fabriàs, Gemma
2007-01-06

Digital.CSIC (Spain)

24

Synthesis and Use of Probes to Investigate the Cryptoregiochemistry of the First Animal Acetylenase

Abad, José Luis; Rodríguez Ropero, Sergio; Camps Díez, Francisco; Fabriàs, Gemma
2006-09-29

Digital.CSIC (Spain)

25

Substrate channelling in an engineered bifunctional aldolase/kinase enzyme confers catalytic advantage for C–C bond formation

Iturrate Montoya, Laura; Sánchez-Moreno, Israel; Doyagüez, Elisa G.; García-Junceda, Eduardo; RSC Publishing
2010-02-11

Digital.CSIC (Spain)

26

Strong covalent bonding between two graphene layers

Andrés Rodríguez, Pedro Luis de ; Ramirez, Rafael ; Verges, Jose A.

We show that two graphene layers stacked directly on top of each other (AA stacking) form strong chemical bonds when the distance between planes is 0.156 nm. Simultaneously, C-C in-plane bonds are considerably weakened from partial double-bond (0.141 nm) to single bond (0.154 nm). This polymorphic f...

DRIVER (Spanish)

27

Strong covalent bonding between two graphene layers

Andrés Rodríguez, Pedro Luis de; Ramírez, Rafael; Verges, Jose A.
2008-01-14

Digital.CSIC (Spain)

28

Strain effects on the surface optical transitions of GaAs

Postigo, Pablo Aitor; Armelles Reig, Gaspar; Briones Fernández-Pola, Fernando
1998-10-15

Digital.CSIC (Spain)

30

Spectral properties and isomerism of nitroenamines. Part 3

Chiara, José Luis; Gómez-Sánchez, Antonio; Bellanato, Juana
1992-01-01

Digital.CSIC (Spain)

31

Simple and Efficient Heterogeneous Copper Catalysts for Enantioselective C−H Carbene Insertion.

Fraile, José M.; García, José I.; Mayoral, José A.; Roldán, Marta
2007-01-27

Digital.CSIC (Spain)

32

Sesquiterpene lactones and other constituents from Matricaria chamomilla L.

Zaiter, Lahcene; Bouheroum, Mohamed; Benayache, Samir; Benayache, Fadila; León, Francisco; Brouard, Ignacio; Quintana, José; Estévez, Francisco; Bermejo, Jaime
2007-05-07

Digital.CSIC (Spain)

34

Role of vibrational anharmonicity in atmospheric radical hydrogen-bonded complexes

Torrent-Sucarrat, Miquel; Anglada Rull, Josep; Luis, J. M.
2009-08-14

Digital.CSIC (Spain)

35

Role of the Molecular Conformation in the Two- and Three-Dimensional Supramolecular Structure of 10 Hydroxyl-N-alkylamides

Foces-Foces, Concepción; López Rodríguez, Matías; Pérez, Cirilo; Martín, Julio D.; Pérez-Hernández, Natalia
2007-04-03

Digital.CSIC (Spain)

36

Role of geometrical relaxation in solution of simple molecules exhibiting anomeric effects

Sánchez Marcos, Enrique; Pappalardo, Rafael R.; Chiara, José Luis; Domene, M. Carmen; Martínez, José M.; Parrondo, Ramón M.
1996-11-18

Digital.CSIC (Spain)

37

Resolidificación con láser de barreras térmicas de circona depositadas por proyección térmica plasma (APS)

Díez Moñux, Juan Carlos; Peña Torre, José Ignacio; Orera Clemente, Víctor Manuel; Sierra, M.
2004-11-01

Digital.CSIC (Spain)

38

Remote plasma chemical vapor deposition silicon oxynitride thin films: Dielectric properties

Hernández Vélez, M.; Sánchez Garrido, Olga; Fernández Gutiérrez, F.; Falcony, C.; Martínez Duart, J. M.
1998-05-01

Digital.CSIC (Spain)

39

Rebuilding gluten network of damaged wheat by means of glucose oxidase treatment

Bonet, Arturo; Rosell, Cristina M.; Pérez Munuera, Isabel; Hernando, Isabel
2007-05-01

Digital.CSIC (Spain)

41

Propiedades , aplicaciones y producción de biotensoactivos: una revisión/ Biosurfactant properties, applications and production: a review

JIMÉNEZ ISLAS, Donaji; MEDINA MORENO, Sergio A.; GRACIDA RODRÍGUEZ, Jorge Noel
2010-02-01

Resumen en español Los tensoactivos son moléculas anfifílicas con una porción hidrofílica y otra hidrofóbica; se localizan preferentemente en la interfase de fluidos con diferentes grados de polaridad como son la de aceite-agua o aire-agua. Las propiedades de un tensoactivo son caracterizadas principalmente por cuatro parámetros: concentración micelar crítica (CMC), número de agregación (n a), balance hidrofílico-lipofilico (HLB) y punto de nube (PN). Estos parámetros indican el (mas) potencial del tensoactivo como agente emulsificante y de superficie, determinando su aplicación en diversas áreas, principalmente a nivel industrial y ambiental. Los tensoactivos son sintetizados vía química o biológica, denominando a los últimos biotensoactivos. Aunque una amplia gama de microorganismos son capaces de sintetizar biotensoactivos, las bacterias son las principales productoras. Los biotensoactivos integran una serie de compuestos cuya estructura puede ser simple -como los ramnolípidos, formados por mono y disacáridos unidos por enlaces glicosídicos a ácidos grasos hidroxilados-, o compleja, como el emulsán, biotensoactivo polimérico complejo que contiene unidades monoméricas de heteropolisacáridos enlazados a lípidos. Los biotensoactivos muestran ventajas sobre los de síntesis química debido a su compatibilidad con el ambiente, baja toxicidad y biodegradabilidad. Sin embargo, su principal desventaja son los elevados costos asociados a su producción. En la presente revisión se describen las propiedades químicas y microbiológicas de tensoactivos y biotensoactivos, así como las diferentes aplicaciones de los últimos, principalmente en el campo de la biorremediación. Además, se analiza la influencia de las principales variables de proceso sobre la producción de biotenso-activos, en particular de los ramnolípidos provenientes de Pseudomonas aeruginosa. Resumen en inglés Surfactants are amphiphilic molecules containing both hydrophilic and hydrophobic parts; these substances are located at the fluid-fluid interface with different degrees of polarity from oil-water or air-water interfaces. The properties of surfactants are characterized principally by four parameters: critical micelle concentration (CMC), aggregation number (n a), hydrophilic-lipophilic balance (HLB) and cloud point (CP). These parameters are indicative of the potential of (mas) the surfactant as an emulsifier and surface-active agent and determine their application, mainly in industry and the environment. Surfactants are synthesized chemically or biologically, in which case they are called biosurfactants. Although an extensive number of microorganisms are capable of synthesizing biosurfactants, they are mainly produced by bacteria. Biosurfactants make up a series of compounds whose structure may be relatively simple such as rhamnolipids, whose structures have mono- and disaccharides joined by glycosidic bonds to hydroxylated carboxylic acids, or more complex such as emulsán, a polymeric biosurfactant with monomeric units of heteropolysaccharides bound to lipids. Biosurfactants have advantages over chemical surfactants due to their compatibility with the environment, low toxicity and biodegradability. However, the principal disadvantage is their high production cost in some cases. In this paper the chemical and microbiological properties of surfactants and biosurfactants are described as well as biosurfactant applications, principally in the bioremediation field. The effect of the main process variables on the production of biosurfactants is also discussed, particularly of rhamnolipids from Pseudomonas aeruginosa.

Scientific Electronic Library Online (Spanish)

42

Propeller-like hydrogen-bonded banana - melamine complexes inducing helical supramolecular organizations

Barberá, Joaquín; Puig, Laura; Romero, Pilar; Serrano, José Luis; Sierra, Teresa
2006-03-15

Digital.CSIC (Spain)

43

Producción y caracterización de cuerpos porosos de hidroxiapatita sintética/ Production and characterization of porous bodies of synthetic hydroxyapatite

González, Jazmín; Escobar, Diana Marcela; Ossa, Claudia Patricia
2008-03-01

Resumen en español El proceso gel-casting se ha usado para preparar materiales cerámicos y metálicos haciendo posible obtener formas con microestructura y propiedades mecánicas controladas. La hidroxiapatita (HA) es un cerámico bioactivo, debido a su capacidad de enlazarse directamente al tejido óseo, sin embargo, presenta muy baja resistencia mecánica. En este trabajo se prepararon espumas de hidroxiapatita usando el proceso gel-casting con porcentajes de sólidos de 40 y 50%. Las es (mas) pumas obtenidas se caracterizaron usando Difracción de Rayos X (XRD), Microscopía Electrónica de Barrido (SEM) y ensayos mecánicos de compresión. Los resultados mostraron que las espumas obtenidas presentan poros abiertos e interconectados con un tamaño alrededor de 100 µm. Las pruebas mecánicas mostraron que a mayor porcentaje de sólidos se incrementa la resistencia a la compresión. Se demuestra que este es un proceso con alto potencial para la fabricación de cuerpos porosos, útiles en cirugía reconstructiva. Resumen en inglés The gel-casting process has been used for the preparation of ceramic and metallic materials making it possible to obtain shapes with controlled microstructure and mechanical properties. Hydroxyapatite (HA) is a bioactive ceramic, due to its capacity to form chemical bonds with the bone tissue but, it has low mechanical resistance. In this work HA foams were prepared using gel-casting, with two solid percentages, 40 and 50%. The obtained foams were characterized by X Ray D (mas) iffraction (XRD), Scanning Electronic Microscopy (SEM) and compression tests. Results show that the foams have open and interconnected pores with sizes close to 100 µm. Mechanical tests indicate that the compressive strength increases by increasing solid percentage. The high potential of this process is demonstrated for the fabrication of porous bodies to be used in reconstructive surgery.

Scientific Electronic Library Online (Spanish)

44

Preparation of half-sandwich osmium-allyl complexes by consecutive c-c bond formation and c-h bond activation reactions

Esteruelas, Miguel A.; González, Ana I.; López, Ana M.; Oliván, Montserrat; Oñate, Enrique
2005-12-21

Digital.CSIC (Spain)

46

Polymeric mechanical sensors with strain gauge readout in a microfluidic system

Calleja, Montserrat; Rasmussen, P.; Johansson, A.; Boisen, Anja
2003-10-01

Digital.CSIC (Spain)

47

Palladium complexes of a phosphorus ylide with two stabilizing groups: Synthesis, structure, and DFT study of the bonding modes

Falvello, Larry R.; Ginés, Juan Carlos; Carbó, Jorge J.; Lledós, Agustí; Navarro, Rafael; Soler, Tatiana; Urriolabeitia, Esteban P.
2006-07-01

Digital.CSIC (Spain)

48

On-line application of visible and near infrared reflectance spectroscopy to predict physical and sensory characteristics of beef quality

Prieto, Nuria; Ross, D. W.; Navajas, E. A.; Nute, G. R.; Richardson, R. I.; Hyslop, J. J.; Simm, G.; Roehe, R.
2009-01-01

Digital.CSIC (Spain)

49

On the nature of the unusually long OO bond in HO3 and HO4 radicals

Mansergas, Alex; Anglada Rull, Josep M.; Olivella, Santiago; Ruiz-López, Manuel F; Martins-Costa, Marilia
2007-09-18

Digital.CSIC (Spain)

50

On the Gas Phase Hydrogen Bond Complexes between Formic Acid and Hydroperoxyl Radical. A Theoretical Study

Torrent-Sucarrat, M. ; Anglada Rull, Josep M

9 pages, 5 tables, 4 figures. | We present a systematic study on the gas-phase hydrogen-bonded complexes formed between formic acid and hydroperoxyl radical, which has been carried out by using B3LYP and CCSD(T) theoretical approaches in connection with the 6-311+G(2df,2p) basis set. For all complex...

DRIVER (Spanish)

52

New selective haloform-type reaction yielding 3-hydroxy-2,2-difluoroacids: theoretical study of the mechanism

Olivella, Santiago; Solé, Albert; Jiménez, Óscar; Bosch, María Pilar; Guerrero, Ángel
2005-02-04

Digital.CSIC (Spain)

53

New arrangement of proteins and lipids in the stratum corneum cornified envelope

López Serrano, Olga; Cócera, Mercè; Wertz, P. W.; López-Iglesias, Carmen; Maza, Alfons de la
2007-03-01

Digital.CSIC (Spain)

54

New Selective Haloform-type Reaction Yielding 3-Hydroxy-2,2-difluoroacids: Theoretical Study of the Mechanism

Olivella, Santiago; Solé, Albert; Jiménez, Óscar; Bosch, María Pilar; Guerrero, Ángel
2005-02-04

Digital.CSIC (Spain)

55

Nanostructural origin of the spin and orbital contribution to the magnetic moment in Fe3−xO4 magnetite nanoparticles

Pérez, N.; Bartolomé, Fernando; García, L. M.; Bartolomé, Juan; Morales Herrero, María del Puerto; Serna Pereda, Carlos J.; Labarta, Amílcar; Batlle, Xavier
2009-03-05

Digital.CSIC (Spain)

56

Multienzyme system for dihydroxyacetone phosphate-dependent aldolase catalyzed C-C bond formation from dihydroxyacetone

Sánchez-Moreno, Israel; García-García, Juan Francisco; García-Junceda, Eduardo; Bastida, Ágatha
2004-01-01

Digital.CSIC (Spain)

57

Microscopic structure and dynamics of molten Se50Te50 alloys

Katcho, N. A.; Zetterström, P.; Lomba, Enrique; Otero Díaz, L. C.
2007-10-10

Digital.CSIC (Spain)

58

Microbial transformation of 18-hydroxy-9,13-epi-ent-pimara-7,15-diene by Gibberella fujikuroi

Fraga, Braulio M.; González, Pedro; Hernández, Melchor G.; Chamy, María C.; Garbarino, Juan A.
2003-01-01

Digital.CSIC (Spain)

59

Mesitylgold(I) and silver(I) perfluorocarboxylates as precursors of supramolecular Au/Ag systems

Fernández, Eduardo J.; Laguna, Antonio; López-de-Luzuriaga, José M.; Montiel, Manuel; Olmos, M. Elena; Pérez, Javier; Puelles, Raquel C.
2006-07-26

Digital.CSIC (Spain)

61

Mechanism of molecular hydrogen dissociation on gold chains and clusters as model prototypes of nanostructures

Zanchet, Alexander; Dorta-Urra, A.; Roncero, Octavio; Flores, F.; Tablero, C.; Paniagua, Miguel; Aguado, Alfredo
2009-01-01

Digital.CSIC (Spain)

62

Macromolecular polyradicals with cyclic triphosphazene as a core. Spectral and electrochemical properties

Carriedo, Gabino A.; García Alonso, Francisco J.; Gómez Elipe, P.; Brillas, Enric; Labarta, Amílcar; Juliá, Lluís
2004-01-09

Digital.CSIC (Spain)

63

MNDO/H and AM1 studies of nitro enamines with intramolecular hydrogen bonds

Sánchez Marcos, Enrique; Maraver, José Joaquín; Chiara, José Luis; Gómez-Sánchez, Antonio
1988-01-01

Digital.CSIC (Spain)

67

In situ optical spectroscopy of Ga dimers on GaP, GaAs and GaSb by surface chemical modulation

Postigo, Pablo Aitor; Armelles Reig, Gaspar; Utzmeier, T.; Briones Fernández-Pola, Fernando
1998-01-01

Digital.CSIC (Spain)

68

Imaging transient species in the femtosecond A-band photodissociation of CH3I

Durá, J.; Nalda, R. de; Amaral, G. A.; Bañares, Luis
2009-10-07

Digital.CSIC (Spain)

69

Glucomanano: propiedades y aplicaciones terapéuticas/ Glucomannan: properties and therapeutic applications

González Canga, A.; Fernández Martínez, N.; Sahagún, A. M.ª; García Vieitez, J. J.; Díez Liébana, M.ª J.; Calle Pardo, Á. P.; Castro Robles, L. J.; Sierra Vega, M.
2004-02-01

Resumen en español La fibra dietética glucomanano se utiliza con cierta frecuencia en Occidente desde hace dos décadas, dadas sus demostradas acciones beneficiosas para la salud, si bien su uso se remonta, en las civilizaciones orientales, a más de mil años. Esta fibra es el principal polisacárido obtenido de los tubérculos de la planta originaria del este asiático Amorphophallus konjac y que pertenece a la familia Araceae. La estructura química del glucomanano incluye Dmanosa y D-g (mas) lucosa (en una proporción 8:5, respectivamente), unidas por enlace ß (1→ 4). El glucomanano es una fibra muy soluble, que posee una excepcional capacidad de captar agua, formando soluciones muy viscosas. Posee un peso molecular y una viscosidad más elevados que cualquier fibra conocida. Se ha demostrado que es eficaz en la obesidad, por la sensación de saciedad que produce; en el estreñimiento debido a que aumenta el volumen fecal; como hipocolesterolemiante interfiriendo en el transporte de colesterol y ácidos biliares; y también disminuye los niveles de glucosa e insulina, probablemente debido a que retrasa el vaciado gástrico y, por tanto, dificulta el acceso de la glucosa a la mucosa intestinal. A estas propiedades beneficiosas, podemos añadir algunos inconvenientes como la producción de flatulencia, molestias abdominales, obstrucciones esofágicas o del tracto gastrointestinal, o incluso puede modificar la biodisponibilidad de otros fármacos que se administren al mismo tiempo que la fibra. Esta revisión recoge las principales características del glucomanano, así como sus propiedades, efectos fisiológicos y aplicaciones terapéuticas. Resumen en inglés Glucomannan is a dietary fiber employed quite frequently in the western countries since two decades now, as its ingestion plays an important role in human health. However, eastern people have used this fiber for more than a thousand years. This dietary fiber is the main polysaccharide obtain from the tubers of the Amorphophallus konjac plant, a member of the family Araceae found in east Asia. The chemical structure of glucomannan consists, mainly, in mannose and glucose i (mas) n the ratio 8:5 linked by ß (1→ 4). glycosidic bonds. This soluble fiber has a extraordinarily high waterholding capacity, forming highly viscous solutions when dissolved in water. It has the highest molecular weight and viscosity of any known dietary fiber. It has been demonstrated that this product is highly effective in the treatment of obesity due to the satiety sensation that it produces; as a remedy for constipation, because it increases the faeces volume; as hypocholesterolemic agent, interfering in the transport of cholesterol and of bile acids and as hypoglycemic and hypoinsulinemic agent, probably, by delaying gastric emptying and slowering glucose delivery to the intestinal mucosa. To the beneficial properties of this fiber, several di sadvantages can be added as the production of flatulence, abdominal pain, esophageal obstruction, lower gastrointestinal obstruction or even the possible modification of the bioavailability of other drugs. This paper reviews the main characteristics of glucomannan, as well as its properties, physiologic effects and therapeutic uses.

Scientific Electronic Library Online (Spanish)

70

Getting specificity from simplicity in putative proteins from the prebiotic Earth

López de la Osa, Jaime; Bateman, David A.; Ho, Sylvia; González, Carlos; Chakrabartty, Avijit; Laurents, Douglas V.
2007-09-12

Digital.CSIC (Spain)

71

From a trinuclear platinum(III) phosphido derivative to a platinum(II) cluster: Formation of a P−C bond

Forniés, Juan; Fortuño, Consuelo; Ibáñez, Susana; Martín, Antonio
2006-04-01

Digital.CSIC (Spain)

72

Fragmentation of carbohydrate anomeric alkoxyl radicals: a new synthesis of 1,1-difluoro-1-iodo alditols

Francisco, Cosme G.; González Martín, Concepción C.; Rodríguez Paz, Nieves; Suárez, Ernesto
2003-10-04

Digital.CSIC (Spain)

74

First-principles calculation of the effect of stress on the chemical activity of graphene

Andrés Rodríguez, Pedro Luis de ; Verges, Jose A.

Graphene layers are stable, hard, and relatively inert. We study how tensile stress affects sigma and pi bonds and the resulting change in the chemical activity. Stress affects more strongly pi bonds that can become chemically active and bind to adsorbed species more strongly. Upon stretch, single C...

DRIVER (Spanish)

77

Evolution of the microstructure, chemical composition and magnetic behaviour during the synthesis of alkanethiol-capped gold nanoparticles

Guerrero, Estefanía; Rojas, T. Cristina; Fernández Camacho, Asunción; Multigner, M.; Crespo, Patricia; Muñoz-Márquez, Miguel Ángel; García, M. A.; Hernando, Antonio
2006-12-21

Digital.CSIC (Spain)

78

Enhancement of the magnetic anisotropy of Co clusters by Au capping.

Luis, F.; Bartolomé, Juan; Bartolomé, Fernando; Martínez, M. J.; García, L. M.; Petroff, F.; Deranlot, C.; Wilhelm, F.; Rogalev, A.
2006-04-26

Digital.CSIC (Spain)

79

Electronic structure, magnetic properties, and microstructural analysis of thiol-functionalized Au nanoparticles: role of chemical and structural parameters in the ferromagnetic behaviour

Guerrero, Estefanía; Muñoz-Márquez, Miguel Ángel; Fernández-Pinel, Enrique; Crespo, Patricia; Hernando, Antonio; Fernández Camacho, Asunción
2008-07-31

Digital.CSIC (Spain)

80

Electronic Structure of Layered Oxides Containing M2O7 (M = V, Nb) Double Octahedral Slabs

Rousseau, Roger; Palacín, M. R.; Gómez-Romero, P.; Canadell, Enric
1996-02-18

Digital.CSIC (Spain)

82

Divergent Behavior in the Cyclopalladation of Phosphorus Ylides and Iminophosphoranes.

Aguilar, David; Aragüés, Miguel Angel; Bielsa, Raquel; Serrano, Elena; Navarro, Rafael; Urriolabeitia, Esteban P.
2007-06-01

Digital.CSIC (Spain)

84

Dihydrogen bond cooperativity in (HCCBeH)n clusters

Alkorta, Ibon; Elguero, José; Solimannejad, Mohammad
2008-08-14

Digital.CSIC (Spain)

86

Coordination and rupture of Methyl C(sp3)−H bonds in osmium−polyhydride complexes with δ agostic interaction

Baya, Miguel; Eguillor, Beatriz; Esteruelas, Miguel A.; Lledós, Agustí; Oliván, Montserrat; Oñate, Enrique
2007-09-01

Digital.CSIC (Spain)

88

Cleavage of N−O Bonds Promoted by Samarium Diiodide: Reduction of Free or N-Acylated O-Alkylhydroxylamines

Chiara, José Luis; Destabel, Christine; Gallego, Pilar; Marco Contelles, José Luis
1996-01-12

Digital.CSIC (Spain)

89

Chemical-structural characterization of solvent and thermal extractable material from perhydrous vitrinites

Iglesias, María José; Río Andrade, José Carlos del; Laggoun-Défarge, Fatima; Cuesta, María José; Suárez Ruiz, Isabel
2003-01-01

Digital.CSIC (Spain)

90
91
92

CARACTERIZACIÓN TEXTURAL Y QUÍMICA DE CATALIZADORES TI-SIO2 CRISTALINOS USADOS EN LA EPOXIDACIÓN DE ÉSTERES GRASOS/ TEXTURAL AND CHEMICAL CHARACTERIZATION OF CRYSTALLINE Ti-SiO2 CATALYSTS USED IN THE EPOXIDATION OF FATTY ESTERS

RIOS, LUIS; RESTREPO, GLORIA; SUÁREZ, RICARDO; CAICEDO, ROSARIO; MAZO, PAULA; FRANCO, ALEXANDER; ECHEVERRI, DAVID
2006-03-01

Resumen en español Centros discretos de TiIV dispersos en una matriz de SiO2 actúan como fuertes aceptores de electrones por lo cual son útiles para la activación de moléculas o funciones químicas densas en electrones. La cantidad de estos centros, su dispersión, accesibilidad y coordinación, determinan su eficiencia química; para determinar estas propiedades, varios materiales Ti-MCM-41 se caracterizaron mediante DRX, FTIR, UV-Vis e isotermas de adsorción de N2; también se determ (mas) inaron la cristalinidad, porosidad y superficie específica de la matriz SiO2 permitiendo correlacionar el ambiente fisicoquímico del titanio y las propiedades texturales del catalizador, con su efectividad en la activación de enlaces O-O presentes en moléculas tipo peróxidos, usados en la epoxidación de aceites vegetales. Los resultados sugieren que la presencia de poros cristalinos, en la epoxidación del metiléster del ácido oleico con TBHP y catalizada con Ti-MCM-41, no es necesaria, puesto que la reacción ocurre principalmente en el área externa a los poros. Lo realmente importante es tener centros de Ti finamente dispersos sobre una área superficial alta y accesible. Por otro lado, la temperatura de reacción deber estar por debajo de 70°C para minimizar la formación de subproductos (cetona). Resumen en inglés Discrete TiIV centers dispersed in a SiO2 matrix acts as strong electron acceptors, therefore, they are useful in activating molecules or moieties which are electron-rich. The amount, dispersion, accessibility and coordination of these centers determine their chemical efficiency. Several Ti-MCM-41 materials where characterized using DRX, FT-IR, UV-Vis and nitrogen adsorption to evaluate the dispersion, coordination and accessibility of Ti centers as well as the crystallin (mas) ity, porosity and surface area of the SiO2 matrix. This study allows a correlation between the chemical environment of titanium, textural properties of the catalyst and its performance in the activation of O-O bonds present in peroxides, used for the epoxidation of plant oils. Results suggest that the presence of crystalline pores, in the epoxidation of oleic acid methylester with TBHP catalyzed by Ti-MCM-41, is not necessary, because the reaction occurs in large extension on the external surface area. The important issue is to have the titanium centers finely dispersed on a relatively high surface area. Temperature should be below 70°C to minimize the ketone formation.

Scientific Electronic Library Online (Spanish)

93

C-H bond activation and subsequent C-C bond formation promoted by osmium: 2-vinylpyridine-acetylene couplings

Esteruelas, Miguel A.; Fernández-Alvarez, Francisco J.; Oliván, Montserrat; Oñate, Enrique
2006-03-18

Digital.CSIC (Spain)

94

Bonding structure and mechanical properties of Ti-B-C coatings

Abad Roldán, Manuel David; Cáceres, Daniel; Pogozhev, Yury S.; Shtansky, Dmitry V.; Sánchez López, Juan Carlos
2009-01-01

Digital.CSIC (Spain)

95

Biosynthesis of 10,12-dienoic fatty acids by a bifunctional Delta11 desaturase in Spodoptera littoralis

Serra, Montserrat; Piña, Benjamín; Bujons Vilàs, Jordi; Camps Díez, Francisco; Fabriàs, Gemma
2006-05-20

Digital.CSIC (Spain)

96

Antifeedant and Phytotoxic Activity of the Sesquiterpene p-Benzoquinone Perezone and Some of its Derivatives

Burgueño-Tapia, Eleuterio; Castillo, Lucía; González-Coloma, Azucena; Joseph-Nathan, Pedro
2008-01-01

Digital.CSIC (Spain)

97

Anions in metallic matrices model: application to the aluminium crystal chemistry

Vegas, Ángel; Santamaría Pérez, David; Marqués, M.; Flórez, M.; García Baonza, V.; Recio, J. M.
2006-04-01

Digital.CSIC (Spain)

98

Anharmonic effects on the structural and vibrational properties of the ethyl radical: A path integral Monte Carlo study

López Ciudad, Telesforo; Ramírez, Rafael; Schulte, Joachim; Böhm, Michael C.
2003-08-22

Digital.CSIC (Spain)

99

Aluminium depletion in NiCrAlY bond coatings by hot corrosion as a function

Mayoral Gastón, María del Carmen; Andrés Gimeno, José Manuel; Bona, M. T.; Higuera, V.; Belzunce, F. J.
2008-02-01

Digital.CSIC (Spain)

100

Alkynoates as a source of reactive alkylinides for aldehyde addition reactions

Armas, Pedro de; García-Tellado, Fernando; Marrero-Tellado, José Juan; Tejedor, David; Maestro, Miguel A.; González-Platas, Javier
2001-05-15

Digital.CSIC (Spain)

101

Activation of the aryl hydrocarbon receptor by carbaryl: Computational evidence of the ability of carbaryl to assume a planar conformation

Casado, Susana; Alonso Giner, Mercedes; Herradón García, Bernardo; Tarazona, José V.; Navas, José M.
2006-12-01

Digital.CSIC (Spain)

102

Achiral bent-core liquid crystals with azo and azoxy linkages: structural and nonlinear optical properties and photoisomerization

Folcia, César L.; Alonso, I.; Ortega, Josu; Etxebarria, Jesús; Pintre, Inmaculada C.; Ros, M. Blanca
2006-08-26

Digital.CSIC (Spain)

103

Ab initio ground state potential energy surfaces for Rg–Br2 (Rg = He, Ne, Ar) complexes

Prosmiti, Rita; Cunha, Carlos; Villarreal, Pablo; Delgado Barrio, Gerardo
2002-06-01

Digital.CSIC (Spain)

104

A uniquely selective inhibitor of the mammalian fetal neuromuscular nicotinic acetylcholine receptor

Teichert, Russell W.; Rivier, Jean; Torres, Josep Lluís; Dykert, John; Miller, Charleen; Olivera, Baldomero M.
2005-01-19

Digital.CSIC (Spain)

105

A theoretical approach to the vibrational analysis of the nitroenamine system

Chiara, José Luis; Gómez-Sánchez, Antonio; Sánchez Marcos, Enrique
1990-01-01

Digital.CSIC (Spain)

107

A helical, aromatic, peptide nanotube

Marco Crisma, Marco; Toniolo, Claudio; Royo, Soledad; Jiménez, Ana I.; Cativiela, Carlos
2006-11-18

Digital.CSIC (Spain)

109

A diversity-oriented strategy for the construction of tetrasubstituted pyrroles via coupled domino processes

Tejedor, David; González-Cruz, David; Marrero-Tellado, José Juan; García-Tellado, Fernando; López Rodríguez, Matías
2004-06-19

Digital.CSIC (Spain)

110

A density functional theory study of the dissociation of H2 on gold clusters: Importance of fluxionality and ensemble effects

Barrio, Laura; Liu, P.; Rodríguez, José A.; Campos Martín, Jose Miguel; Fierro, Jose L. G.
2006-10-27

Digital.CSIC (Spain)