Coherent low-energy charge transport in a diffusive S-N-S junction.

We have studied the current-voltage characteristics of diffusive mesoscopic Nb-Cu-Nb Josephson junctions with highly transparent Nb-Cu interfaces. We consider the low-voltage and high-temperature regime eV < epsilon(c) < k(B)T, where epsilon(c) is the Thouless energy. The observed excess current as well as the observed subharmonic Shapiro steps under microwave irradiation suggest the occurrence of low-energy coherent multiple Andreev reflection.

Case series: catatonic syndrome in young people.

This article reviews all recent (1977-1997) reports on catatonic adolescents and summarizes the 9 consecutive cases seen at the authors' institution during the past 6 years. Catatonia occurs infrequently in adolescents (0.6% of the inpatient population), but it appears to be a severe syndrome in adolescents of both sexes. Diagnoses associated with catatonia are diverse, including in this series: schizophrenia (n = 6), psychotic depression (n = 1), mania (n = 1), and schizophreniform disorder (n = 1). Two patients had a previous history of pervasive developmental disorder. In the literature, catatonia was also reported in children with organic condition (e.g., epilepsy, encephalitis). Therapeutic management depends on the specific causes, but several points need to be stressed: (1) the frequency of neuroleptic-induced adverse effects; (2) the potential efficacy of sedative drugs on motor signs; (3) the possible use of electroconvulsive therapy; and (4) the necessity to manage family reactions and fears, which are frequent causes of noncooperation. It is concluded that catatonia is an infrequent but severe condition in young people. While symptomatology, etiologies, complications, and treatment are similar to those reported in the adult literature, findings differ with regard to the female-male ratio and the relative frequencies of associated mental disorders.

[Use of electroconvulsive therapy in the adolescent]. / Utilisation de l'électroconvulsivothérapie chez l'adolescent.

Despite the progress of pharmocotherapy, electroconvulsive therapy (ECT) is still used in a majority of countries to treat severe intractable mental disorders of the youth, yet few studies have been conducted to assess its use for individuals under 20-year-old. Efficacy, indications, side effects, technical characteristics and outcome are uncertain. A review of the 96 cases reported in the literature shows that: 1) its average frequency in adolescent psychiatric practice is similar throughout western nations and can be estimated around one ECT every year per million people; 2) intractable mood disorders, both manic and depressive episodes, are its main indications, since ECT treated more than 90% of the 66 cases reported; ECT can also offer an interesting alternative in some schizoaffective and schizophrenic episodes, in particular catatonic ones; 3) tolerance appears to be good, although secondary effects may occur. The most serious ones are infrequent spontaneous seizures and more common memory loss. Although no prospective studies are available on the evolution of cognitive side effects, they seem to disappear within a few weeks.