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  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 843-851 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The C state of Na3 has been explored in detail by the methods of resonant two-photon ionization spectroscopy and photofragmentation spectroscopy of a supercooled cluster beam. The photofragmentation spectrum, recorded by depletion of Na3 from the beam, reveals a long progression of bands that had been invisible to the two-photon ionization method, and it appears that ultrafast fragmentation occurs for all levels more than 400 cm−1 above the zero-point level. This is consistent with earlier observations of Na D-line emission following Na3 excitation in this region, assuming the responsible channel is Na2 2X and Na 2P production. The vibronic fine structure of the C band system is complex at lower energies, and yields to a detailed explanation only through consideration of the dynamical Jahn–Teller effect. This analysis demonstrates that the C state has electronic symmetry E‘, and is subject to a symmetry-lowering deformation of 180 cm−1, or 1.4 times the frequency of the e' vibrational mode of D3h Na3. The corresponding minimum energy structure is an obtuse isosceles triangle (65° apex angle), but the barrier to pseudorotation (estimated to be 40 cm−1) is small. Furthermore, the computed vibronic wave functions imply that only the lowest few states are well described within the adiabatic Born–Oppenheimer approximation; at intermediate energies the spectrum is correspondingly very irregular, while at higher energies a near harmonic regularity returns by virtue of the relatively small magnitude of the Jahn–Teller distortion. These quantitative conclusions are intermediate among those pertaining to the other known states of Na3, and, in combination with them, permit extensive comparison with the results of high quality electronic structure computations. The tentative assignment is to the 12E to 22E‘ electronic transition (united atom 1S21Px,y to 1S21Dxz,yz).
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 3100-3110 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Antimony clusters are produced by the gas aggregation method. They are found to be built from Sb4 units. The Sb+4n clusters are demonstrated to relax their excess energy by evaporation of a tetramer and the binding energy of Sb4 in the cluster is measured to be about 1.3 eV, well below the binding energy of a Sb atom in the bulk (≈2.75 eV). The ionization potentials of Sb4n clusters are studied as a function of the size and the observed evolution confirms the nonmetallic character of their structure. These results are compared with those obtained for bismuth clusters which exhibit a very different behavior. Finally the possible metastable character of Sb4n structure is discussed and illustrated by experiments performed as a function of inert gas temperature in the clusters source.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 3295-3299 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Indium clusters are produced by the inert gas condensation technique. The ionization potentials are found higher for small clusters than for the indium atom. This result is interpreted by the p character of the bonding as in aluminum. The fragmentation processes are studied and discussed. The behavior of the ionization potential explains why the evaporation of neutral monomers is an unlikely channel in the dissociation processes. Finally doubly charged indium clusters are detected for n≥15 and their ionization threshold is determined. Triply charged clusters are also observed.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 3479-3490 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The Rydberg spectrum of Na2 has been shown previously to alternate when increasing energy between "stroboscopic fringes'' which correspond to a well known separable Hund's coupling case (a), and a complex, unidentifiable intermediate coupling. We use this system as a prototypic example to test some current ideas on the correspondence between classical chaos and properties of quantum spectra. We first determine the phase space structure and transition to chaos in classical mechanics. We then determine the change in line intensities and level spacing statistics in quantum mechanics. We show that this system has the expected behavior in the semiclassical limit in the presence of classical chaos, except for a peculiarity in level spacing statistics, but that this behavior is not a signature of chaos, since the same system shows similar behavior for some values of the parameters which correspond to a nonchaotic situation in classical mechanics. We discuss also some problems related to the nonvalidity of the semiclassical limit.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 4620-4622 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The vibronic level spectrum of the ground state of the alkali trimer Na3 has been observed via stimulated emission spectroscopy of a supercooled metal cluster beam. Results reported herein use the C state as an intermediate, and reveal strong transitions to combinations of the symmetric stretch and bending modes, along with highly detailed fine structure.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 91 (1987), S. 2626-2630 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 15 (1989), S. S76 
    ISSN: 1432-1238
    Keywords: Organ transplantation ; Kidney transplantation ; Heart transplantation ; Heart and lung transplantation ; Liver transplantation ; Small intestine transplantation ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Organ transplantations have opened a new field in medicine and particularly in pediatrics. The kidney was the first organ to be regularly transplanted and there are now more than 2000 children who have received a kidney graft. Cadaver kidneys or living-related donor (LRD) kidneys can be used since an adult kidney may be grafted in a young child. Cadaver graft survival exceeds 85% at 1 year in recent single centre reports and patient survival is above 95%, the results being even better with LRD. Some complications may be observed in the long term, such as bone osteonecrosis, hypertension or infections. Rehabilitation is generally remarkable and growth which remained abnormal in 1/3 of cases under conventional treatment seems to improve markedly with cyclosporin. In the future, the development of kidney transplantation could lead hopefully to a drastic decrease in the number of children on dialysis. Liver transplantation is now performed in children with biliary atresia and metabolic diseases. There is no age limit for grafting a liver, the only problem being to find a pediatric cadaver donor of similar size. It is also possible to use an adult liver after hepatectomy. There were 170 liver grafts recorded in children in Europe in December 1986, and the long-term survival thanks to cyclosporin is exceeding 80% in some units. Thanks to cyclosporin, programs of cardiac transplantation for children are rapidly developing. The main indications are gross-congenital cardiac malformations or severe functional abnormality not compatible with life. Newborns have been grafted with success. The only problem is also to find a suitable pediatric donor. At the end of 1984, there were 88 cadaver transplantations reported in children, and this number is growing rapidly. Survival is estimated above 70% at 1 year. Indications for heart and lung transplantation are more numerous than for the heart alone, including severe cardiac malformations with abnormality of pulmonary circulation and a number of pulmonary diseases. A close similarity in the size of donor and recipient is mandatory. The immediate results are generally good, but the final outcome remains under evaluation. First investigated in animals, small intestine transplantation has been added recently to the list of possible organ transplantations in children. Indications are extensive intestinal resections, or malformations. The initial results are encouraging, but the long-term outcome remains under evaluation.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 1 (1987), S. 245-247 
    ISSN: 1432-198X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 1 (1987), S. 525-530 
    ISSN: 1432-198X
    Keywords: Cystinosis ; Nephronophthisis ; Alport's syndrome ; Corneal deposits ; Tapeto-retinal degeneration ; Senior-Löken Syndrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ocular involvement is a common feature of three herediatary nephropathies: cystinosis, nephronophthisis and Alport's syndrome. The follow-up of 25 cases of infantile cystinosis over a period of 26 years demonstrated that the corneal and retinal epithelium were affected in the same way as the kidney epithelium. Corneal involvement induced photophobia and discomfort, but actual blindness was mainly due to retinal involvement, and therefore no corneal graft was performed. The use of topical cysteamine appears to be promising, but its production raises many questions so no definitive conclusions may be made. Since 1965, 51 patients with nephronophthisis have had ocular examinations; all patients had characteristic clinical symptoms and histological findings. The first group, which consisted of 18 children, all under 10 years of age, was found to have obvious chorioretinal degeneration. The second group, which consisted of 11 children, had a normal ocular examination and normal electroretinogram (ERG). The third group, consisting of 22 children, had a normal clinical examination but ERG tracings with variable alterations. In 28 instances of Alport's syndrome, two types of ocular abnormalities have been observed. In six cases, an anterior lenticonus was noted, which caused a major decline in visual acuity. Retinopathy, which did not affect vision, was observed in 13 cases.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-198X
    Keywords: Chronic renal failure ; End-stage kidney disease ; Children ; Pancreatitis ; Haemodialysis ; Peritoneal dialysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ten clinical episodes of acute pancreatitis (AP) occurred in six patients (mean age 10 years, range 3–15 years) with chronic renal failure (CRF) during a 9-year period (1977–1986). The underlying cause of CRF was vesicoureteral reflux (2); urethral valves (1); ureterohydronephrosis (1); nephronopthisis (1) and a haemolytic uraemic syndrome which occurred 12 years before (1). In all patients a diagnosis of AP was established both on clinical grounds and with a serum amylase level of 〉600 IU/1. In 3 patients laparotomy was performed because of suspected appendicitis. All patients required exclusive parentenral feeding (mean duration 25 days) and 2 patients had a partial pancreatectomy. No patient developed pancreatic pseudocysts, 2 patients experienced one relapse (3 and 21 months later) and 1 patient had two relapses and died. Mean duration of follow up was 3 years (range 1–10 years). Possible aetiological factors were: choledochal cyst (1); parotitis without a rise in mumps antibodies (1); familial dyslipidaemia but without AP in other family members (1), and aluminium intoxication with hypercalcaemia and convulsive encephalopathy treated with valproic acid in 1 patient. Severe hyperparathyroidism with radiological signs was absent in all patients. Transplantation had been performed either before AP in 2 patients (1 and 3 years before AP) or had followed AP in 1 patient (7 years after) without occurrence or relapse of AP.
    Type of Medium: Electronic Resource
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