Electron paramagnetic resonance of Yb3+ ions in a concentrated YbRh2Si2 compound with heavy fermions

The EPR signal from localized ytterbium ions was observed in an undoped YbRh2Si2 compound with heavy fermions in the temperature range from 1.5 to 25 K. The exponential contribution dominating the temperature dependence of EPR line width at temperatures above 15 K was shown to be caused by the random transitions from the ground to the first excited Stark sublevel of the Yb3+(4f13) ion with the activation energy Δ = 115 K. © 2003 MAIK "Nauka/Interperiodica"

Electron spin resonance with geff ≈ 4.2 in YBa2Cu3O6.35. model of chain copper-oxygen fragments

Systematic measurements are made of ESR spectra with g ≈ 4.2 in YBa2Cu3O6+y compounds with various doping indices y. Temperature dependences of the spectrum intensity show that the ground states of the centers are singlet and the energies of the excited states MS = ±1 correspond to 8-11 K. In general, the intensity of the ESR spectra varies with time and depends on the sample preparation technology. The most probable models for the paramagnetic centers studied are considered to be chain fragments of copper ions of variable valence. General laws governing the energy structure of these centers are described. © 2000 MAIK "Nauka/Interperiodica"

Electron paramagnetic resonance of Yb3+ ions in a concentrated YbRh2Si2 compound with heavy fermions

The EPR signal from localized ytterbium ions was observed in an undoped YbRh2Si2 compound with heavy fermions in the temperature range from 1.5 to 25 K. The exponential contribution dominating the temperature dependence of EPR line width at temperatures above 15 K was shown to be caused by the random transitions from the ground to the first excited Stark sublevel of the Yb3+(4f13) ion with the activation energy Δ = 115 K. © 2003 MAIK "Nauka/Interperiodica"

Electron paramagnetic resonance of Yb3+ ions in a concentrated YbRh2Si2 compound with heavy fermions

The EPR signal from localized ytterbium ions was observed in an undoped YbRh2Si2 compound with heavy fermions in the temperature range from 1.5 to 25 K. The exponential contribution dominating the temperature dependence of EPR line width at temperatures above 15 K was shown to be caused by the random transitions from the ground to the first excited Stark sublevel of the Yb3+(4f13) ion with the activation energy Δ = 115 K. © 2003 MAIK "Nauka/Interperiodica"

Marqueurs et facteurs prédictifs de la réponse thérapeutique à la clozapine (revue de la bibliographie)

La détermination des marqueurs ou de facteurs prédictifs cliniques ou paracliniqes de la réponse thérapeutique à un traitement par la clozapine présenterait un intérêt indéniable pour le clinicien. L'objectif de ce travail est d'effectuer une revue critique des facteurs cliniques et paracliniques prédictifs de la réponse thérapeutique. Les facteurs identifiés se subdivisent en six grandes catégories : les facteurs cliniques (anamnestiques, cliniques généraux, symptomatologie schizophrénique, symptomatologie cognitive et examens électrophysiologiques), les marqueurs biologiques (taux plasmatiques de la clozapine et de ses métabolites), les marqueurs biochimiques (acide homovanilique, sérotonie, norépinéphrine), les marqueurs endocriniens, les marqueurs pharmacogénétiques, l'imagerie cérébrale. Résultats : Une symptomatologie schizophrénique globale initiale et un niveau d'autonomie antérieure plus importants ainsi qu'une faible valeur initiale du rapport des concentrations acide homovanilique/ acide 5-hydroxtindolacétique ont été identifiés chez les répondeurs. Trois marqueurs potentiellement prédictifs ont été identifiés sous traitement : l'amélioration de l'onde P 50, la diminution du métabolisme du glucose dans le cortex préfrontal et la diminution du volume du noyau caudé. Une concentration plasmatique de la clozapine supérieure à 350 ng/ml semble permettre d'obtenir une meilleure réponse thérapeutique. Conclusion : il n'existe pas à ce jour de marqueur univoque de la réponse à un traitement par la clozapine.ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Electron spin resonance with geff ≈ 4.2 in YBa2Cu3O6.35. model of chain copper-oxygen fragments

Systematic measurements are made of ESR spectra with g ≈ 4.2 in YBa2Cu3O6+y compounds with various doping indices y. Temperature dependences of the spectrum intensity show that the ground states of the centers are singlet and the energies of the excited states MS = ±1 correspond to 8-11 K. In general, the intensity of the ESR spectra varies with time and depends on the sample preparation technology. The most probable models for the paramagnetic centers studied are considered to be chain fragments of copper ions of variable valence. General laws governing the energy structure of these centers are described. © 2000 MAIK "Nauka/Interperiodica"

Electron spin resonance with geff ≈ 4.2 in YBa2Cu3O6.35. model of chain copper-oxygen fragments

Systematic measurements are made of ESR spectra with g ≈ 4.2 in YBa2Cu3O6+y compounds with various doping indices y. Temperature dependences of the spectrum intensity show that the ground states of the centers are singlet and the energies of the excited states MS = ±1 correspond to 8-11 K. In general, the intensity of the ESR spectra varies with time and depends on the sample preparation technology. The most probable models for the paramagnetic centers studied are considered to be chain fragments of copper ions of variable valence. General laws governing the energy structure of these centers are described. © 2000 MAIK "Nauka/Interperiodica"

Electron spin resonance with geff ≈ 4.2 in YBa2Cu3O6.35. model of chain copper-oxygen fragments

Systematic measurements are made of ESR spectra with g ≈ 4.2 in YBa2Cu3O6+y compounds with various doping indices y. Temperature dependences of the spectrum intensity show that the ground states of the centers are singlet and the energies of the excited states MS = ±1 correspond to 8-11 K. In general, the intensity of the ESR spectra varies with time and depends on the sample preparation technology. The most probable models for the paramagnetic centers studied are considered to be chain fragments of copper ions of variable valence. General laws governing the energy structure of these centers are described. © 2000 MAIK "Nauka/Interperiodica"