Non-destructive functionalisation for atomic layer deposition of metal oxides on carbon nanotubes: effect of linking agents and defects.

The hybridisation of metal oxides and nanocarbons has created a promising new class of functional materials for environmental and sustainable energy applications. The performance of such hybrids can be further improved by rationally designing interfaces and morphologies. Atomic layer deposition (ALD) is among the most powerful techniques for the controlled deposition of inorganic compounds, due to its ability to form conformal coatings on porous substrates at low temperatures with high surface sensitivity and atomic control of film thickness. The hydrophobic nature of the nanocarbon surface has so far limited the applicability of ALD on CNTs. Herein we investigate the role of structural defects in CNTs, both intrinsic and induced by acid treatment, on coverage, uniformity and crystallinity of ZnO coatings. Furthermore, we demonstrate the potential of small aromatic molecules, including benzyl alcohol (BA), naphthalene carboxylic acid (NA) and pyrene carboxylic acid (PCA), as active nucleation sites and linking agents. Importantly, only PCA exhibits sufficiently strong interactions with the pristine CNT surface to withstand desorption under reaction conditions. Thus, PCA enables a versatile and non-destructive alternative route for the deposition of highly uniform metal oxide coatings onto pristine CNTs via ALD over a wide temperature range and without the typical surface corrosion induced by covalent functionalisation. Importantly, preliminary tests demonstrated that the improved morphology obtained with PCA has indeed considerably increased the hybrid's photocatalytic activity towards hydrogen evolution via sacrificial water splitting. The concept demonstrated in this work is transferable to a wide range of other inorganic compounds including metal oxides, metal (oxy)nitrides and metal chalcogenides on a variety of nanocarbons.

Red tides in the Gulf of Mexico: Where, when, and why?

[1] Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus-rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron-rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen-poor sea water. They and the co-occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near-bottom seed populations to CDOM-rich surface waters of coastal regions, light-inhibition of the small red tide of ~1 ug chl l(-1) of ichthytoxic K. brevis is alleviated. Thence, dead fish serve as a supplementary nutrient source, yielding large, self-shaded red tides of ~10 ug chl l(-1). The source of phosphorus is mainly of fossil origin off west Florida, where past nutrient additions from the eutrophied Lake Okeechobee had minimal impact. In contrast, the P-sources are of mainly anthropogenic origin off Texas, since both the nutrient loadings of Mississippi River and the spatial extent of the downstream red tides have increased over the last 100 years. During the past century and particularly within the last decade, previously cryptic Karenia spp. have caused toxic red tides in similar coastal habitats of other western boundary currents off Japan, China, New Zealand, Australia, and South Africa, downstream of the Gobi, Simpson, Great Western, and Kalahari Deserts, in a global response to both desertification and eutrophication.

[Effectiveness and tolerance of zotepine in a double-blind comparison with perazine in schizophrenic patients]. / Wirksamkeit und Verträglichkeit von Zotepin im Doppelblindvergleich mit Perazin bei schizophrenen Patienten.

40 inpatients suffering from a schizophrenia (ICD-9) were treated with either zotepine or perazin. The study was continued for a period of 28 days. Assessment of clinical efficacy was effected via BPRS, AMDP, CGI and SANS; tolerance was assessed by means of Simpson's scale. In addition, EEG, ECG and laboratory controls were conducted. The overall therapeutic efficacy was good, and it was not possible to distinguish one group from the other, i.e. both substances were equally effective, judged by means of the psychopathometric tools that were at our disposal. In 11 patients of the zotepine group and in 9 patients of the perazin group, slight extrapyramidal symptoms were observed. No clinically relevant changes were seen in EEG, ECG and laboratory controls in both groups.

[Clinical effectiveness of zotepine in treatment of negative schizophrenic symptoms. Results of an open and a double-blind controlled trial]. / Klinische Wirksamkeit von Zotepin in der Behandlung schizophrener Minussymptomatik. Ergebnisse einer offenen und einer doppelblind-kontrollierten Studie.

The clinical action of Zotepine was examined in an open and in a randomised double-blind controlled study in in-patients displaying a productive or minus pattern of symptoms within the framework of a schizophrenic disease or schizoaffective psychosis. The present paper discusses only the results achieved in treating schizophrenic minus patterns of signs and symptoms. In Study I 20 schizophrenic patients were treated with two different Zotepine dosages. Group 2 (n = 12) showed at an average daily dose of 168 +/- 15 mg (150-190 mg) a significant improvement (p less than 0.05) of the anergy subscore in the BPRS scale as well as a significant improvement of the subscores affective flattening, anhedonia/asociality and attentional imparvement in the SANS scale, compared with Group 1 (n = 8) with an average daily dose of 270 +/- 37 mg (240-340 mg). This improvement developed already during the first two weeks of the treatment. In Study II the antipsychotic action of Zotepine compared to that of perazine was studied under double-blind conditions. The average daily dose in the Zotepine group (n = 20) was around 241 +/- 70 mg (106-396 mg), in the perazin group (n = 19) at 348 +/- 09 mg (214-575 mg). With regard to the BPRS subscore anergy and all the subscores of the SANS scale, there was a distinct improvement without significant group differences. Both substances were comparably well tolerated.

Effects of alpha 2-receptor blockade in addition to tricyclic antidepressants in therapy-resistant depression.

It was investigated whether yohimbine, a primarily alpha 2-receptor blocking agent, may have an antidepressant effect when given in addition to tricyclic antidepressants. After at least two unsuccessful preliminary antidepressant treatments for a minimum of 4 weeks each, patients received, in addition to tricyclics, yohimbine in increasing doses for 7 days. None of the five patients investigated demonstrated any improvement in depressive symptomatology and four of the five suffered from such side effects as severe anxiety, inner restlessness, psychomotor agitation, and tremor. During intravenous administration of 2.5 and 20 mg yohimbine, significant increases in norepinephrine values and systolic blood pressure were observed. It was concluded that a combination of yohimbine and tricyclic antidepressants seems to have little indication due to yohimbine's lack of efficacy and the high incidence of side effects in the treatment of severely depressed inpatients.

Zotepine, a neuroleptic drug with a bipolar therapeutic profile.

Zotepine, a new tricyclic compound, was investigated in 20 schizophrenic patients in two different dosage groups. Group I (n = 8) received Zotepine in a high dosage of 270 mg +/- 37 mg/die. The other group (group II; n = 12) received a low dosage of 168 mg +/- 15 mg/die. In both groups 2 patients dropped out before the end of the treatment period because of clinical deterioration. In both groups, Zotepine manifested a rapid antipsychotic effect, good tolerability, and sedative properties during the initial days. Additionally there was a stronger positive influence on negative symptoms in the group with low dosage treatment.

Preliminary experiences and results with the Munich version of the Andreasen Scale. Assessment of productive and negative symptoms in chronic schizophrenic patients.

The Andreasen Scale (SANS), an instrument for evaluating negative symptoms in schizophrenic patients, was translated at the Psychiatric Hospital of Munich and tested on 35 chronic schizophrenic inpatients at the Regensburg State Mental Hospital. In addition, psychopathology was evaluated with the BPRS, sociodemographic data were collected, and cognitive performance was evaluated by the MMS. Also, VBR was determined on the basis of CAT scans. Our results suggest that the SANS is a reliable instrument for measuring negative symptoms; however, the symptom complexes are affected by age, duration of illness and hospitalization, thus making a clear distinction between negative symptoms per se and the effects of hospitalization questionable.

Oxaprotiline in the treatment of endogenous depressed inpatients an early clinical trial.

Oxaprotiline (C 49/802 BA), a further development and structural analogue of maprotiline, is characterized by a very potent and extremely specific inhibitory effect on the re-uptake of norepinephrine. In an open early phase II study oxaprotiline was investigated in 10 inpatients with endogenous depression with regard to its antidepressive efficacy and occurrence of adverse effects. Oxaprotiline was given in a dosage up to 225 mg over a period of 28 days. 9 out of 10 patients completed the study, and, of these, 5 were found to be either very much improved or much improved. Standardized rating scales (HAMD, Bf-S, EWL-K) indicated significant improvement after 4 weeks of treatment. Except dry mouth, generally mild, there were no remarkable side effects; there was no influence of oxaprotiline on heart, cardiovascular and routine laboratory parameters. The results of this study indicate that oxaprotiline is an effective antidepressant without significant adverse effects.

The effect of fluperlapine in acute psychotic patients.

Fluperlapine (NB 106 689), a dibenzazepine chemically and pharmacologically similar to clozapine, was investigated in 28 patients with regard to antipsychotic efficacy and occurrence of adverse effects. In an open early phase II study patients were given fluperlapine over a period of 26 days. The average daily dosage was 300 mg. Five patients had to be withdrawn from the trial during the first week due to side effects or therapeutic inefficacy, 23 patients were examined during the period planned. The substance proved to have fast-acting antipsychotic effect with few adverse effects and no extrapyramidal motor disturbances.

Detoxification treatment for chronic schizophrenic patients: experimental results and data from a survey.

Blood detoxification as a treatment of schizophrenia has been studied intensively since 1977 by a number of research centers. Results of an open study on 10 chronic schizophrenic patients--two showing improvement--were less favorable than those reported in the initial publications. In order to possibly identify a subgroup of responders to this treatment, a survey was undertaken in which 95 centers were invited to participate. Of the 95 centers which originally treated schizophrenic patients with detoxification and which were asked to send data on these patients to the Registry of the European Dialysis and Transplant Association, 39 centers replied (35 from Europe and four from the United States). From the 100 patients reported on in Europe, 17 were reported to be very much improved and 22 to be improved. Of the patients from the United States, 86% were reported as improved. No subgroup of responders could be identified, and differences between centers concerning nosological subgroups, treatment methods, and results were so great that no real comparison was possible. Although data from this survey are not totally conclusive, in connection with the updated literature they do not encourage further research in this treatment of schizophrenia.

Blood purification treatment of schizophrenia.

In order to gather information about the usefulness of blood purification methods as a treatment for chronic schizophrenic patients, "mini-questionnaires" were sent to all European centers working with this method. The questionnaires consisted of two parts, one asking the psychiatrist about the disease itself and the evaluation of treatment, the other one asking the nephrologist about the specific method used. --A preliminary report, based on the evaluation of 53 questionnaires indicated--although far from offering conclusive results--that all schizophrenic patients did not profit equally from the therapy and that patients treated for less than 6 hours per week were not likely to improve. Implications for further research are discussed.

Hemoperfusion in chronic schizophrenics: a critical report.

Ten chronic schizophrenic patients were treated with hemoperfusion on a weekly or twice weekly basis for 6 to 10 weeks. Two of the patients improved markedly, while the condition of three of them deteriorated. These findings indicate that this method might not be of general usefulness in the treatment of chronic schizophrenic patients.