Search

Neodymium-doped barium borate glasses are investigated for their potential as fluorescent concentrators for the near infrared spectral range. Additional doping of the glasses with silver oxide and subsequent heat treatment leads to a reduction of the doped silver ions and to the formation of metallic silver nanoparticles. The formation of the silver nanoparticles is indicated by a broad surface plasmon-related extinction band at approximately 410 nm. The influence of the silver nanoparticles on the fluorescence properties is investigated.

Thermal processing of asmade fluorozirconate glasses which were additionally doped with neodymium and chlorine ions leads to enhanced upconversion fluorescence intensities. The samples were annealed between 240 °C and 290 °C and the optimum value of upconversion intensity was found for the 270 °C sample. The development of glasses doped with Er, whose luminescence characteristics make it a better choice for application as an upconversion layer on silicon solar cells, is in progress. In addition, we present external quantum efficiency measurements of a silicon solar cell with a NaYF4:Er3upconverter. We also show a theoretical analysis where erbium transitions can be enhanced selectively to increase upconversion efficiency. © 2008 WILEYVCH Verlag GmbH & Co. KGaA, Weinheim

The suicide-related mortality among patients with affective disorders is approximately 30 times higher, and overall mortality 2 to 3 times higher, than suicide-related mortality in the general population. Lithium has demonstrated possibly specific antisuicidal effects apart from its prophylactic efficacy: it significantly reduces the high excess mortality of patients with affective disorders. To date, suicide-prevention effects have not been shown for antidepressant or anticonvulsant long-term treatment. Clozapine appears to reduce the suicide rate in schizophrenia patients. Against this background, guidelines and algorithms for selecting an appropriate prophylactic strategy for affective disorders should consider the presence of suicidality in patient history. Appropriate lithium prophylaxis prevents approximately 250 suicides yearly in Germany, although lithium salts are infrequently prescribed within the National Health Scheme (specifically, to 0.06% of the population). Rational treatment strategies most likely would demand that prescription rates be about 10 times higher.

Corticotropin-releasing hormone (CRH) and proenkephalin (PENK) are hypothalamic peptides involved in the stress response and hypothalamic-pituitary axis regulation. Previous research has implicated these peptides in the pathogenesis of affective disorders. In this study we investigated two polymorphisms located in the genes that code for CRH and PENK by means of association and linkage analyses. A total of 138 bipolar patients and 108 controls were included in the association study. In addition, 24 families were available for linkage analysis, including six families of probands with documented periodic positivity of dexamethasone suppression tests (DST) during remission. We found no association of bipolar disorder with either gene. Similarly, we did not find any evidence of linkage (P = 0.56 for CRH and 0.52 for PENK) in the entire sample or in the subsample of families of DST positive probands. In conclusion, our study does not support the hypothesis that genes coding for CRH or PENK contribute to the genetic susceptibility to bipolar disorder. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:178–181, 2000. © 2000 Wiley-Liss, Inc.

Objective Findings from a recent international multi-centre trial are compatible with the idea that long-term lithium treatment extends the survival of patients suffering from affective disorders to match the general population. A similar reduction of mortality was found in Canadian patients, although important questions remained to be answered about cardiovascular and suicide mortality, and patient selection.Method Based on data collected in a study (I) from lithium clinics in Canada, Denmark, Germany and Austria, an analysis was carried out of suicide and cardiovascular mortality in patients who received prophylactic lithium treatment.Results In patients given lithium for two years or longer (n = 641), both suicide and cardiovascular mortality were the same as, or only slightly higher than, in the general population; in patients given lithium for less than two years (n = 186), both mortalities remained high. The reduced mortality is not likely to be the result of selection because the patients who were treated briefly and those treated for a longer time did not differ in important mortality variables.Conclusions In addition to its ability to prevent recurrences, prophylactic lithium treatment appears capable of reducing both the excess suicide risk and excess cardiovascular mortality of affective illness.

In this investigation the frequency and clinical importance of suicidal behavior in patients with a primary diagnosis of personality disorder was studied. The sample was drawn from a group of over 8000 psychiatric inpatients admitted to a university psychiatric hospital. Only patients with a primary diagnosis of personality disorder were included. In the subgroup of 226 patients with this diagnosis, it was found that the rate of suicidality was almost as great as that of patients with a primary diagnosis of major affective disorder (39% as opposed to 41%), despite the absence in all but 3% of these patients of an additional diagnosis of affective disorder. Further, this figure was considerably higher than that for all psychiatric inpatients (24%). Suicidal patients had more suicide attempts in their history and had a more serious depressive syndrome, despite the fact that only 3% fulfilled the criteria for major affective disorder. The conclusion which can be drawn is that a high degree of suicidality should not be regarded as exclusively linked to a primary diagnosis of major affective disorder.