Sample records for FLUORESCENCIA DE RESONANCIA (resonance fluorescence)
from WorldWideScience.org

Sample records 1 - 18 shown.



1

Los ácidos húmicos de leonardita sobre características espectroscópicas de la materia orgánica de un suelo en la cuenca del lago de Valencia

Rivero, Carmen; Senesi, Nicola; D'Orazio, Valeria
2004-04-01

Resumen en español Los productores de bananos (Musa AAA), de la cuenca del Lago de Valencia (Venezuela), aplican al suelo soluciones de ácidos húmicos de leonardita (AHL) al 15%, cada tres meses, durante el ciclo de producción. El posible efecto de dichas aplicaciones sobre los ácidos húmicos del suelo (AHS) fue evaluado. Se obtuvieron AHS sin aplicación de AHL (T0) y suelos con un año (T1) y dos años (T2) de dicha aplicación. La caracterización de los AHS se realizó mediante an� (mas) �lisis elemental y técnicas espectroscópicas: fluorescencia, infrarrojo con transformados de Fourier (IR-TF) y resonancia de spin electrón (ESR). Los resultados indican que el efecto de la aplicación de AHL sobre la estructura de los AHS es limitado: solo se observa una tendencia al incremento en el contenido de oxígeno y la concentración de radicales libres en los AHS. Resumen en inglés Banana (Musa AAA) farmers in the Valencia lake basin, Venezuela, apply 15% of leonardite humic acid solution to the soil every three month during the banana cycles production. The possible effects of these applications on soil humic acid were evaluated. Soil humic acids were obtained from fields which received no leonardite humic acid (T0) and soils with one year (T1) and tow years (T2) of application. Soil humic acid were characterized by elemental analysis and spectrosc (mas) opic techniques: fluorescence, fourier transforms infrared and electron spin resonance. Results indicate that the effects of leonardite humic acid applications on the structure of soil humic acids are limited: only an increasing trend of oxygen contents and free radical concentration in the soil's hunmic acids was observed.

Scientific Electronic Library Online (Spanish)

2

EFECTO DEL ULTRASONIDO EN LA SÍNTESIS DE ARCILLA PILARIZADA CON ALUMINIO EN MEDIO CONCENTRADO/ EFFECTS OF ULTRASOUND IN THE SYNTHESIS OF ALUMINUM PILLARED CLAY IN CONCENTRATED MEDIA/ EFEITO DE ULTRA-SOM NA SÍNTESE DE ARGILA PILARIZADA COM ALUMÍNIO CONCENTRADA NO MEIO

Sanabria, Nancy R; Molina, Rafael A; Moreno, Sonia
2008-12-01

Resumen en portugués Este estudo foi realizado síntese de bentonite pilarizada com alumínio concentrada no meio, utilizando ultra-som na fase de intercalação. O agente pilarizante foi preparado por hidrólise de AlCl3 com NaOH, seguido de precipitação solução Na2SO4 e redisolución Ba(NO3)2. O agente pilarizante foi caracterizado por fluorescência de raios-X (FRX), difração de raios X(DRX), microscopia eletrônica de varredura (SEM) e ressonância magnética nuclear de alumínio (2 (mas) 7Al-RMN).A argila pilarizada foi caracterizado por FRX, DRX e fisiadsorción N2 a 77 K. A bentonite pilarizada com alumínio concentrada no meio e utilizando ultra-som na fase de intercalação, introduz propriedades estruturais e texturais comparável ao alterada na sequência do método convencional: suspensões e diluído intercalação tempo elevado. Adicionalmente, o uso de suspensões concentradas argila-agente pilarizante e da aplicação do ultra-som na fase de intercalação permitir uma diminuição do volume de água entre 90-95% e uma redução do tempo de intercalação entre 70-93% no que diz respeito ao método convencional de pilarización. Resumen en español En este trabajo se realizó la síntesis de bentonita pilarizada con aluminio en medio concentrado, empleando ultrasonido en la etapa de intercalación. El agente pilarizante fue preparado por hidrólisis del AlCl3 con NaOH, seguido de precipitación con disolución de Na2SO4 y redisolución en Ba(NO3)2, y fue caracterizado por fluorescencia de rayos X (FRX), difracción de rayos X (DRX), microscopía electrónica de barrido (SEM) y resonancia magnética nuclear de alumin (mas) io (27Al-RMN). La arcilla pilarizada fue caracterizada por FRX, DRX y fisiadsorción de N2 a 77 K, revelando propiedades estructurales y texturales comparables a la modificada siguiendo la metodología convencional: suspensiones diluidas y tiempos de intercalación elevados. El empleo de suspensiones concentradas de arcilla- agente pilarizante y la aplicación de ultrasonido en la etapa de intercalación permiten una disminución en el volumen de agua entre el 90-95% y una reducción en el tiempo de intercalación entre el 70–93%respecto almétodo convencional de pilarización. Resumen en inglés The synthesis of pillared bentonite with aluminum in concentrated media, using ultrasound at the intercalation step was done. The pillaring agent was prepared by hydrolysis of AlCl3 with NaOH, followed by precipitation with a Na2SO4 disolution and redisolution with a Ba(NO3)2. The pillaring agent was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance for aluminum (27Al-NMR). The pillared cl (mas) ay was characterized by XRF, XRD and N2 adsorption to 77 K. The pillared bentonite with aluminum in concentrated media using ultrasound at the intercalation step, presents structural and textural properties comparable to the sample modified by the conventional method: diluted suspensions and high intercalation time. Additionally, the use of clay-pillaring agent in concentrated suspensions and ultrasound at the intercalation step allows a 90-95% decrease in the volume of water and a reduction in the intercalation times between 70-93% with respect to the conventional synthesis.

Scientific Electronic Library Online (Spanish)

3

Tras la huella de las células madre/ On the track of stem cells

Hernández Ramírez, Porfirio; Dorticós Balea, Elvira
2010-08-01

Resumen en español En los últimos años ha surgido un gran interés en conocer la biodistribución de las células madre en el organismo después que son infundidas o inyectadas directamente en una parte del cuerpo. Para esto se han usado diferentes procederes, entre ellos, el marcaje de las células con diferentes fluorocromos, tales como la proteína con fluorescencia verde y la proteína con fluorescencia roja; o bien se les hace una transfección con plasmidos que codifican proteínas (mas) fluorescentes o se emplean sondas moleculares fluorescentes para la identificación de cromosomas. Recientemente se han introducido técnicas imagenológicas de avanzada no invasivas, entre las que tenemos la resonancia magnético nuclear, así como procederes basados en el marcaje con radionúclidos para la obtención de imágenes detectadas por tomografía por emisión de positrones (PET, del inglés positron emission tomography), o por tomografía computarizada por emisión de fotón único (SPECT, del inglés single- photon emission computed tomography). Resumen en inglés In past years there was an increasing interest by to know about the biodistribution of stem cells in organism after its perfusion or direct injection in a part of the body. Thus, we used different procedures including the cell labeling with distinct fluorochromes, such as the green fluorescence protein and the red fluorescence protein or a plasmid transfection codifying the fluorescent proteins of fluorescent molecular stents to identify the chromosomes. Recently non-inva (mas) sive leading imaging techniques have been introduced including nuclear magnetic resonance. As well as procedures based on radionuclide labeling to obtain the positron emission tomography (PET) images or by photon-emission computed tomography (SPECT).

Scientific Electronic Library Online (Spanish)

4

Understanding the role of thiol and disulfide self-assembled DNA receptor monolayers for biosensing applications

Carrascosa, Laura G.; Martinez, Lidia; Huttel, Yves; Román García, Elisa Leonor; Lechuga, Laura M.
2010-04-01

Digital.CSIC (Spain)

5

The location and properties of the Taxol binding center in microtubules: a picosecond laser study with fluorescent taxoids

Lillo, M. Pilar; Cañadas, Olga; Dale, Robert. E.; Acuña Fernandez, Alberto Ulises
2000-01-01

Digital.CSIC (Spain)

6

The association of DNA and stable catanionic amino acid-based vesicles

Rosa, Mónica; Morán, María del Carmen; Miguel, Maria da Graça; Lindman, Björn
2007-01-13

Digital.CSIC (Spain)

7

Síndrome de Williams: estudio clínico, citogenético, neurofisiológico y neuroanatómico/ Williams syndrome: Clinical, cytogenetic, neurophysiological and neuroanatomic features in 44 patients

Aravena C, Teresa; Castillo T, Silvia; Carrasco C, Ximena; Mena G, Ismael; López C, Javier; Rojas O, Juan P; Rosemberg P, Carol; Schröter G, Carolina; Aboitiz D, Francisco
2002-06-01

Resumen en inglés Background: Williams syndrome (WS) is a genetically based disorder caused by deletion of elastin and contiguous genes on chromosome 7q11.23. This syndrome is characterized by multiorganic involvement with dysmorphic facial features and a distinctive cognitive profile. It is an interesting model for elucidation of relationships between brain, cognition and genes. Patients have a visual-spatial cognition impaired with relative strengths in social and language abilities. Aim (mas) : To report clinical, cytogenetic, neurophysiological and neuroanatomic features in 44 patients referred as WS. Patients and methods: Forty four patients, aged 2 to 17 years, with the clinical diagnosis of Williams syndrome were studied with fluorescence in situ hybridization (FISH). In three cases, electrophysiological and neuroimaging studies were performed. Result: The deletion was confirmed in 23 patients. In three patients with neurophysiological studies, event related potentials suggested a cognitive difficulty in detecting and processing visual stimuli. Magnetic resonance imaging showed normal brain morphology. SPECT showed hypoperfusion of the right frontal lobe and bilateral anterior cingulum hyperperfusion. Conclusions: There are functional alterations in the brains of patients with Williams, which may be related to the cognitive deficits (Rev Méd Chile 2002; 130: 631-37)

Scientific Electronic Library Online (Spanish)

8

Synthesis and physicochemical study of the laminin active sequence: SIKVAV

Almiñana, Nuria; Alsina, M. Asunción; Espina, Marta; Reig Isart, Francesca
2003-06-04

Digital.CSIC (Spain)

9

Soil health—a new challenge for microbiologists and chemists

Arias, M. Enriqueta; González-Pérez, José A.; González-Vila, Francisco J.; Ball, Andrew S.
2005-03-01

Digital.CSIC (Spain)

10

Selective photobleaching of chlorophylls and carotenoids in Photosystem I particles under high-light treatment

Andreeva, Atanaska; Abarovaа, Silvia; Stoitchkovaa, Katerina; Picorel Castaño, Rafael; Velitchkova, Maya

The definitive version is available at: www.blackwell-synergy.com | Photosystem I particles (PSI-200) isolated from spinach leaves were studied by means of absorbance, 77K fluorescence, and resonance Raman spectroscopy. The aim was to obtain better insight into the changes of in the pigment spectral...

DRIVER (Spanish)

11

Selective photobleaching of chlorophylls and carotenoids in Photosystem I particles under high-light treatment

Andreeva, Atanaska; Abarovaа, Silvia; Stoitchkovaa, Katerina; Picorel Castaño, Rafael; Velitchkova, Maya
2007-01-06

Digital.CSIC (Spain)

12

New fluorescent octadecapentaenoic acids as probes of lipid membranes and protein-lipid interactions

Mateo, C. Reyes; Souto, André A.; Amat-Guerri, Francisco; Acuña Fernandez, Alberto Ulises
1996-10-01

Digital.CSIC (Spain)

13

New Transmembrane Polyene Bolaamphiphiles as Fluorescent Probes in Lipid Bilayers

Quesada, Ernesto; Acuña Fernandez, Alberto Ulises; Amat-Guerri, Francisco
2001-05-28

Digital.CSIC (Spain)

14

Nanomechanics for specific biological detection

Álvarez, Mar; Carrascosa, Laura G.; Tamayo, Javier; Calle Martín, Ana; Lechuga, Laura M.
2003-07-28

Digital.CSIC (Spain)

15

Giannini, V.

Giannini, V.; Sánchez Gil, José Antonio
2008-05-01

Digital.CSIC (Spain)

16

Evidence for distinct antagonist-revealed functional states of 5-hydroxytryptamine(2A) receptor homodimers

Brea, José; Castro, Marián; Giraldo, Jesús; López-Giménez, Juan F.; Padín, Juan Fernando; Quintián, Fátima; Cadavid, Maria Isabel; Vilaró, Maria Teresa; Mengod Los Arcos, Guadalupe; Berg, Kelly A.; Clarke, William P.; Vilardaga, Jean-Pierre; Milligan, Graeme; Loza, Maria Isabel
2009-03-11

Digital.CSIC (Spain)