Theoretical investigation of the lowest-lying electronic structure of LuI molecules.

CASSCF/MRCI calculations using Effective Core Potential (ECP) basis sets for both Lu and I atoms, have been performed for the first 22 electronic states in the representation (2s+1)Λ((±)) for the LuI molecule. This investigation included the corresponding 43 molecular states in the representation Ω((±)) when taking the spin-orbit coupling (SOC) in consideration. Calculated potential energy curves (PECs) have been displayed. Spectroscopic constants T(e), ω(e), ω(e)χ(e), B(e) and the internuclear distance R(e) have been calculated for the ground state and for the low-lying electronic states situated below 40,410 cm(-1) and for their corresponding components with SOC. The transition dipolar moments between states have been given at the minimum position R(e)=2.75 Å of the ground state X(1)Σ(+). The calculated set of singlet and triplet states provides a theoretical prediction for more than 19 yet unobserved electronic states.

Updated potential energy function of the Rb2 a(3)Σu(+) state in the attractive and repulsive regions determined from its joint analysis with the 2(3)Π0g state.

We report new experimental data for the Rb2 a(3)Σu(+) and 2(3)Π0g states obtained using the Perturbation Facilitated Infrared-Infrared Double Resonance (PFIIDR) technique. The results include ro-vibrational term values of the 2(3)Π0g state and resolved fluorescence spectra of the 2(3)Π0g→a(3)Σu(+) transitions for a wide range of rotational and vibrational quantum numbers. An analysis of these data confirms the initial assignment of the transitions to the a(3)Σu(+) state reported in our earlier work [B. Beser, V. B. Sovkov, J. Bai, E. H. Ahmed, C. C. Tsai, F. Xie, L. Li, V. S. Ivanov, and A. M. Lyyra, J. Chem. Phys. 131, 094505 (2009)]. The potential energy functions of the Rb2 a(3)Σu(+) and 2(3)Π0g states are derived from a simultaneous fit of the available experimental data. The improved potential function of the Rb2 a(3)Σu(+) state spans both the attractive and repulsive regions starting with internuclear distance R ∼ 4.5 Å.

Joint analysis of the Cs2 a3Σu+ and 1g (3(3)Π1g) states.

Sets of experimental data on the Cs(2) a(3)Σ(u)(+) and 1(g) (3(3)Π(1g)) states, including the bound-bound and bound-free fluorescence spectra, are analyzed simultaneously to produce the potential energy curves of both states in the form of the Morse long range multiparameter function. The attractive branch of the a(3)Σ(u)(+) state potential is improved relative to the one reported in our earlier work [F. Xie, V. B. Sovkov, A. M. Lyyra, D. Li, S. Ingram, J. Bai, V. S. Ivanov, S. Magnier, and L. Li, J. Chem. Phys. 130, 051102 (2009)], in which the data on this state alone were analyzed. Besides, the new potential of this state also includes the repulsive branch in the range spanned by the bound-free fluorescence spectra. We have not found experimental evidence of the double minimum character of the 3(3)Π(1g) state potential, predicted by ab initio calculations, at least up to v = 8. This fact testifies that the upper state observed is better described by the Hund coupling case (c), in which the case (a) electronic basis states are intermixed by the strong spin-orbit interaction.

Theoretical investigation of the Omega(g,u)(+/-) states of K2 dissociating adiabatically up to K(4p 2P(3/2)) + K(4p 2P(3/2)).

A theoretical investigation of the electronic structure of the K(2) molecule, including spin-orbit effects, has been performed. Potential energies have been calculated over a large range of R up to 75a(0) for the 88 Omega(g,u)(+/-) states dissociating adiabatically into the limits up to K(4p (2)P(3/2))+K(4p (2)P(3/2)). Equilibrium distances, transition energies, harmonic frequencies, as well as depths for wells and heights for barriers are reported for all of the bound Omega(g,u)(+/-) states. Present ab initio calculations are shown to be able to reproduce quite accurately the small structures (wells and barrier) displayed at very long-range (R>50a(0)) by the (2,3)1(u) and (2)0(g)(-) purely long-range states. As the present data could help experimentalists, we make available extensive tables of energy values versus internuclear distances in our database at the web address http://www-lasim.univ-lyon1.fr/spip.php?rubrique99.

Experimental investigation of the Cs2 a 3Sigma(u)+ triplet ground state: multiparameter Morse long range potential analysis and molecular constants.

We have observed the vibrational levels v(") = 0-40 of the Cs(2) a (3)Sigma(u)(+) state by perturbation facilitated infrared-infrared double resonance excitation and spectrally resolved fluorescence measurements, and derived a multiparameter Morse long range potential and molecular constants based on these data.

Comparison of Autler-Townes splitting based absolute measurements of the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) electronic transition dipole moment with ab initio theory.

We report a comparison between experimental and theoretical electronic transition dipole moment values for the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) system. The experimental results are based on measuring the absolute magnitude of the transition dipole matrix elements from Autler-Townes splitting of rovibrational transitions for different R-centroid values. The ab initio theoretical calculations of the transition dipole moment for the (7)Li(2) A (1)Sigma(u) (+)-X (1)Sigma(g) (+) system were performed using two different quantum-mechanical models: an all-electron valence bond self-consistent-field method and a pseudopotential molecular orbital method. As expected for the smallest molecule with core electrons, the agreement between experiment and theory is very good.

The K2 2(3)Pi(g) state: new observations and analysis.

Totally 3045 transitions into the 2(3)Pi(g) v = 0-42, J = 0-103, Omega = 0, 1, 2 rovibrational levels have been observed by infrared-infrared double resonance fluorescence excitation and two-photon spectroscopy. Molecular constants including the spin-orbit interaction parameters are obtained. Although the K2 2(3)Pi(g) state dissociates to the 4s + 3d atomic limit, it is strongly mixed with the 3P ionic states in the range of the potential well. This mixing results in a relatively large equilibrium internuclear distance Re = 5.254 A and a larger spin-orbit constant A0 approximately 14.17 cm(-1) than that of the atomic limit -2.33 cm(-1). Strong perturbations of the 2(3)Pi(g) levels observed are attributed to the spin-orbit coupling with the 4(1)Sigma(g)+ state.

Measurement of the electronic transition dipole moment by Autler-Townes splitting: Comparison of three- and four-level excitation schemes for the Na2 A 1Sigma(u)+ - X 1Sigma(g)+ system.

We present a fundamentally new approach for measuring the transition dipole moment of molecular transitions, which combines the benefits of quantum interference effects, such as the Autler-Townes splitting, with the familiar R-centroid approximation. This method is superior to other experimental methods for determining the absolute value of the R-dependent electronic transition dipole moment function mu(e)(R), since it requires only an accurate measurement of the coupling laser electric field amplitude and the determination of the Rabi frequency from an Autler-Townes split fluorescence spectral line. We illustrate this method by measuring the transition dipole moment matrix element for the Na2 A 1Sigma(u)+ (v' = 25, J' = 20e)-X 1Sigma(g)+ (v" = 38, J" = 21e) rovibronic transition and compare our experimental results with our ab initio calculations. We have compared the three-level (cascade) and four-level (extended Lambda) excitation schemes and found that the latter is preferable in this case for two reasons. First, this excitation scheme takes advantage of the fact that the coupling field lower level is outside the thermal population range. As a result vibrational levels with larger wave function amplitudes at the outer turning point of vibration lead to larger transition dipole moment matrix elements and Rabi frequencies than those accessible from the equilibrium internuclear distance of the thermal population distribution. Second, the coupling laser can be "tuned" to different rovibronic transitions in order to determine the internuclear distance dependence of the electronic transition dipole moment function in the region of the R-centroid of each coupling laser transition. Thus the internuclear distance dependence of the transition moment function mu(e)(R) can be determined at several very different values of the R centroid. The measured transition dipole moment matrix element for the Na2 A 1Sigma(u)+ (v' = 25, J' = 20e)-X 1Sigma(g)+ (v" = 38, J" = 21e) transition is 5.5+/-0.2 D compared to our ab initio value of 5.9 D. By using the R-centroid approximation for this transition the corresponding experimental electronic transition dipole moment is 9.72 D at Rc = 4.81 A, in good agreement with our ab initio value of 10.55 D.

Theoretical determination of highly excited states of K2 correlated adiabatically above K4p + K4p.

The electronic structure of the K(2) molecule is revisited to describe the 36 highly excited states dissociating into the three limits K(4s) + K(4f), K(4s) + K(6p), and K(4s) + K(5d), which have not yet been investigated theoretically. Potential energy curves and spectroscopic constants are (re)displayed for the 98(1,3)Lambda(g,u) ((+,-)) molecular states correlated adiabatically to the limits up to K(4s) + K(5d). For the 10 states dissociating adiabatically into K(4p) + K(4p) and limits above for which experimental data are available, averaged errors of present results are found to be Delta R(e) = 0.07a(0), Delta T(e) = 50 cm(-1), Delta omega(e) = 0.8 cm(-1) and Delta D(e) = 60 cm(-1). Full energy data are available at the following address http://lasim.univ-lyon1.fr/allouche/k2.html

[Antenatal diagnosis of congenital left ventricular aneurysm]. / Diagnostic anténatal d'un anévrisme congénital du ventricule gauche.

Congenital aneurysm of the left ventricle is a rare condition of unknown origin, the main differential diagnosis of which is the diverticulum. The natural history of this pathology is well known in adults and adolescents, contrary to those forms diagnosed by foetal echocardiography. Based on a case of congenital left ventricular aneurysm diagnosed ante-natally and a review of the literature, the authors propose echocardiographic prognostic factors useful for prenatal management. Thus, early antenatal diagnosis, size and progression of the aneurysm, signs of antenatal cardiac failure, are poor prognostic factors and should be discussed during parent counselling.

[A case of atrial flutter after umbilical venous catheterization]. / Une observation de flutter auriculaire après pose de cathéter veineux ombilical.

UNLABELLED: Isolated atrial flutter is an extremely rare form of supraventricular tachycardia in the neonatal period. It may be initiated by central venous catheterization. CASE REPORT: A male infant was born at 35 weeks by cesarean section for placenta praevia. He was eutrophic. Apgar score was 10 at 1 and 5 minutes. He secondary developed a respiratory distress syndrome. He was then ventilated by nasal CPAP. Immediately after an umbilical venous catheterization, a tachycardia appeared without preexistent cardiac dysfunction. An intravenous dose of adenosine (Striadyne) showed a characteristic sawtooth pattern of P waves on inferior leads. The cardiac-US examination was normal. This atrial flutter was converted to normal sinus rhythm by transoesophageal pacing, without adjunction of antiarrhythmic drugs. The newborn was weaned from mechanical ventilation 48 hours later and discharged from hospital at seven days post natal age. His development and clinical examination were normal two months later. CONCLUSION: The isolated atrial flutter is rare in the neonate. It may be triggered by a venous catheterization. Transoesophageal atrial pacing is safe and effective for conversion.

[Cardiogenic shock in an infant due to rupture of an aneurysm of the sinus of Valsalva into the left ventricle]. / Choc cardiogénique d'un nourrisson révélant une rupture intraventriculaire gauche d'un anévrisme du sinus de Valsalva.

The authors report the case of a 15 month-old infant admitted to the intensive care unit for cardiogenic shock due to rupture of an aneurysm of the right anterior sinus of Valsalva into the left ventricle, associated with massive aortic regurgitation. The patient underwent a Ross procedure with resection of the aneurysm. This is a very rare condition because rupture of the aneurysm into the left ventricle has not been previously reported in a young girl to the best of the authors' knowledge. Moreover, a Ross procedure has not been previously described in this indication. The case illustrates the diagnostic difficulty associated with this pathology and underlines the necessity of thinking of this diagnosis in infants with appearances of dilated cardiomyopathy and aortic regurgitation.

[Antenatal atrial tachycardia. Two case reports]. / Tachycardies atriales anténatales. A propos de 2 cas.

The authors report two cases of foetal supraventricular tachycardia in healthy hearts with 1/1 atrioventricular conduction which turned out to be atrial tachycardias in the postnatal period. The first foetus had permanent tachycardia at 190/minute at 34 weeks' amenorrhea with left ventricular dysfunction at 36 weeks. In the postnatal period, treatment with digoxine and amiodarone restored sinus rhythm and normal left ventricular function. Permanent foetal tachycardia, even at a rate of less than 200 beats/minute, should suggest an arrhythmia and may lead to left ventricular dysfunction in utero. The other foetus had an aneurysm of the foramen ovale with paroxysmal tachycardias at 220/minute without cardiac dysfunction. A Holter at 1 month showed paroxysmalatrial tachycardia. Postnatal rhythm monitoring is necessary in paroxysmal foetus tachycardia, especially with prenatal aneurysm of the foramen ovale.

Thoracic pheochromocytoma revealed by ventricular tachycardia. Clinical case and review of the literature.

A case of thoracic extra-adrenal pheochromocytoma was observed in a 13-year-old girl. The initial clinical symptoms consisted of her being unwell after effort over a period of 3 years. The diagnosis was suggested after a recorded episode of paroxysmal ventricular tachycardia with concomitant hypertension, which reproduced the characteristic symptoms. Biochemical analysis confirmed hypersecretion of catecholamines and morphological examinations showed the presence of an isolated left median thoracic tumor. One year after surgical excision, the patient remained completely asymptomatic, in spite of resuming intense sporting activity. The diagnosis of ectopic pheochromocytoma should be considered as a possible etiology of cardiac rhythm disturbances or hypertension in children. Thorough biochemical and radiological examination including MIBG radioisotope scanning should be carried out systematically before surgical excision; pheochromocytomas in children are frequently extra-adrenal (30%), multifocal (50%) or associated with multiple endocrine neoplasms (NEM).

[Bundle of His tachycardia and chronic reciprocating rhythm: rare forms of prenatal tachycardia]. / Tachycardie hissienne et rythme réciproque chronique. Formes rares de tachycardie anténatale.

In cases of permanent tachycardia, ante-natal diagnosis of chronic reciprocating rhythms with long RP' intervals or His bundle tachycardias is difficult. The authors report two cases of permanent foetal tachycardia with 1/1 atrioventricular conduction. In one case, the tachycardia rate was 170/min with anasarca treated by amiodarone in view of a family history of His bundle tachycardia. In the other case, the tachycardia rate was 200/min but with no signs of cardiac failure and was, therefore, not treated. The ECG at birth confirmed the diagnosis of His bundle tachycardia in the first case and identified a chronic reciprocating rhythm in the other.

Potential Energies, Permanent and Transition Dipole Moments for Numerous Electronic Excited States of NaK.

Recent experimental works have been devoted to the spectroscopy of highly excited states of NaK, confirming the accuracy of our previous calculations [S. Magnier and Ph. Millié, Phys. Rev. A: Gen. Phys. 54, 204 (1996)] of spectroscopic constants and potential curves. Among them, [E. Laub, I. Mazsa, S. C. Webb, J. La Civita, I. Prodan, Z. J. Zabbour, R. K. Namiotka, and J. Huennekens, J. Mol. Spectrosc. 193, 376 (1999)] have deduced from their measurements the variation of the transition dipole moment with the interatomic distance for the transition X(1)Sigma+ --> (3)(1)Pi. They have shown that a large discrepancy was observed with the previous ab initio calculations currently used as a guide for spectroscopic experiments. Upon request of several experimentalists, we have computed again potential curves for electronic states correlated up to Na(4p) + K(4s) as well as relevant permanent and transition dipole moments. We present extensive predictions for the electronic structure of NaK (potential energies, dipole moments) for which numerical data have been listed in a data base available as supplementary data. Copyright 2000 Academic Press.

Transcatheter closure of apical ventricular muscular septal defect combined with arterial switch operation in a newborn infant.

This report describes a case of transposition of the great arteries and apical muscular ventricular septal defect in a newborn infant successfully treated by transcatheter closure of the septal defect with the Amplatzer duct occluder device followed by an arterial-switch operation within the first 2 weeks of life. Cathet. Cardiovasc. Intervent. 49:173-176, 2000.

Prenatal diagnosis of a familial form of junctional ectopic tachycardia.

Junctional ectopic tachycardia (JET) is a rare cardiac arrhythmia characterized by atrio-ventricular dissociation, a high rate junctional escape rhythm and poor clinical tolerance in neonates and infants. Sudden infant death has been reported. The intra-uterine presentation of this arrhythmia is unknown. We report a familial form of JET with antenatal diagnosis. A sustained tachycardia at a rate of 170 beats/min with a 1:1 conduction was diagnosed in a hydropic fetus at a gestational age of 32 weeks. The older brother had presented with prenatal hydrops and junctional ectopic tachycardia was diagnosed at birth. Assuming that this arrhythmia was a JET, amiodarone was given to the mother in order to control the fetal tachycardia. The arrhythmia persisted with a 1/1 pattern but at a slower ventricular rate (140 beats/min). The ECG performed at birth revealed a narrow QRS tachycardia with a ventricular rate of 180 beats/min and a 1/1 retrograde conduction. Amiodarone therapy was continued with the addition of propanolol. Postnatal echocardiography revealed normal chambers and left ventricular dysfunction with a left ventricular shortening fraction of 17 per cent. Subsequent ECGs and Holter monitoring demonstrated typical electrocardiographic features of JET. Both parents had a normal ECG and Holter monitoring. A fetal tachycardia of moderately high rate with a 1/1 retrograde conduction and poor cardiac tolerance can be due to JET. In such cases, the use of amiodarone can be considered as a first line drug.

[Role of right-to-left atrial shunt in exercise tolerance of patients with Ebstein anomaly]. / Rôle du shunt droit-gauche atrial dans la diminution de la tolérance à l'effort de la maladie d'Ebstein asymptomatique.

The aim of this study was to assess cardiorespiratory tolerance to exercise in children with non-operated, paucisymptomatic and untreated froms of Ebstein's anomaly. The authors undertook a prospective study in 11 children, mean age 9.6 years, who had lung function tests, cardiorespiratory exercise stress tests (bicycle ergometry N = 8, treadmill N = 3) and contrast echocardiography. All parameters of spirometry were normal. Contrast echocardiography showed a right-to-left interatrial shunt in 7 children (group 1) whereas the remaining 4 children had no shunt (group 2). The resting oxygen saturation was 97.4 +/- 2%, with no difference between the two groups. On the other hand, oxygen saturation at peak VO2 (VO2 max) was 90 +/- 9.5%, significantly lower in group 1 than in group 2 (85.7 +/- 2.2% vs 98.2 +/- 1.2%; p = 0.03). In group 1, the VO2 max was correlated to oxygen saturation (r = 0.98; p < 0.001, N = 6). The oxygen desaturation was correlated with presence of a right-to-left interatrial shunt (p = 0.01). The reduced exercise tolerance of non-operated, paucisymptomatic children with Ebstein's anomaly is due to a right-to-left interatrial shunt. In patients with poor exercise tolerance, contrast echocardiography is advised for the detection of these atrial shunts.