Removal and toxicity evaluation of a diverse group of drugs from water by a cyclodextrin polymer/pulsed light system.

The presence of pharmaceutical compounds (PhCs) in the effluents of wastewater treatment plants (WWTPs) is an ecological concern. The issue could be alleviated by trapping those substances by cyclodextrin (CD) polymers or photolyzing them by pulsed light (PL). Consequently, a sequential CD polymer/PL system was tested for the removal of PhCs. Firstly, a survey detected the presence of recurrent PhCs in the effluents of local WWTPs. Then, pure water was spiked with 21 PhCs, 100 µg/L each one. The three-dimensional network provides amphiphilic features to the CD polymer that reduced the pollutant concentration by 77 %. Sorption involves a plead of physical and chemical mechanisms hindering the establishment of a general removal model for all compounds. The performed simulations hint that the retention capacity mainly correlates with the computed binding energies, so that theoretical models are revealed as valuable tools for further improvements. The complementary action of PL rose the elimination to 91 %. The polymer can be reused at least 10 times for ibuprofen (model compound) removal, and was able to eliminate the ecotoxicity of an ibuprofen solution. Therefore, this novel sequential CD polymer/PL process seems to be an efficient alternative to eliminate PhCs from wastewater.

Nanocomposites based on highly luminescent nanocrystals and semiconducting conjugated polymer for inkjet printing.

In this work nanocomposites based on organic-capped semiconductor nanocrystals formed of a core of CdSe coated with a shell of ZnS (CdSe@ZnS), with different sizes, and a semiconducting conjugated polymer, namely poly[(9,9-dihexylfluoren-2,7-diyl)-alt- (2,5-dimethyl-1,4-phenylene)] (PF-DMB) have been investigated. The nanocomposites are prepared by mixing the pre-synthesized components in organic solvents, thereby assisting the dispersion of the organic-coated nano-objects in the polymer host. UV-vis steady state and time-resolved spectroscopy along with (photo)electrochemical techniques have been performed to characterize the obtained materials. The study shows that the embedded nanocrystals increase the PF-DMB stability against oxidation and, at the same time, extend the light harvesting capability to the visible spectral region, thus resulting in detectable photocurrent signals. The nanocomposites have been dispensed by means of a piezo-actuated inkjet system. Such inks present viscosity and surface tension properties well suited for stable and reliable drop-on-demand printing using an inkjet printer. The fabrication of arrays of single-color pixels made of the nanocomposites and micrometers in size has been performed. Confocal and atomic force microscopy have confirmed that inkjet-printed microstructures present the intrinsic emission properties of both the embedded nanocrystals and PF-DMB, resulting in a combined luminescence. Finally, the morphology of the printed pixels is influenced by the embedded nanofillers.

[An exploratory study of a personality disorders questionnaire]. / Etude exploratoire d'un questionnaire sur les troubles de la personnalité

INTRODUCTION: This exploratory study combined a preliminary evaluation of the French version of Hyler's [Hyler S.E. Personality Questionnaire (PDQ-4 plus). New York: New York State Psychiatric Institute; 1994] Personality Diagnostics Questionnaire (PDQ-4 plus) with an investigation into whether Eysenck's personality dimensions allow us to differentiate between subjects diagnosed by the PDQ-4 plus as showing at least one personality disorder (PD) and control subjects. PARTICIPANTS: A group of 129 French undergraduate students completed the PDQ-4 plus, a self-report questionnaire designed to assess the 12 PDs of the DSM-IV (10 PDs and two additional diagnoses included in the appendix of the DSM-IV), and, at the same time, the Eysenck Personality Questionnaire Revised-Abbreviated (EPQ RA). METHODS: The PDQ-4 plus diagnoses were scored using a two-stage process in which students with questionnaire scores at or above the threshold level for at least one PD (82 students=63.56%) were asked to complete individual interviews about the PDs concerning them. In order to minimize the number of false positives generated, these interviews were scored using the Clinical Significance Scale. Following these interviews, 35 students (27.13%) were classified as showing one or more PDs. The remaining 84 students (72.87%) were classified as control subjects (no PDs). In the population as a whole, studies have shown the prevalence of any DSM-IV defined personality disorder to be between 9 and 15%; however, personality disorders are much more frequently diagnosed in younger subjects (Ekselius L., Tillfors M., Furmark T., & Fredrikson M. Personality disorders in the general population: DSM-IV and ICD-10 defined prevalence as related to sociodemographic profile. Personality and Individual Differences, 2001, 30: 311-320). The second step in the study was to compare EPQ RA scores for the control subjects, subjects showing a particular PD and subjects showing the other PDs. RESULTS: For all the PDs studied, the control subjects attained lower scores on the Neuroticism scale than the subjects showing one or more PDs. Subjects showing depressive or schizotypal PDs attained particularly high scores on the Neuroticism scale: a result that differentiates these subjects from the control subjects and from subjects showing other PDs. Scores on the Extraversion scale were similar for all the subjects with the exception of those showing depressive or schizotypal PDs. Subjects with a depressive or a schizotypal PD were generally more introverted than the control subjects and the subjects showing other PDs. Significant differences between all three groups of subjects were noted on the Psychoticism scale, at least for the PDs studied here. Psychoticism scale scores were generally higher for the subjects showing one or more PDs than for the control subjects, except in the cases of the subjects showing compulsive-obsessional and paranoiac PDs, whose Psychoticism scores were not significantly different from those of the control subjects. The Psychoticism scores for the subjects with antisocial (cluster B) or schizotypal (cluster A) PDs were statistically higher than the scores for the control subjects and for the subjects showing other PDs. In summary, Neuroticism was more prevalent among the subjects showing depressive and schizotypal PDs. In terms of extraversion, only subjects showing depressive and schizotypal PDs could be differentiated from the control subjects and from the subjects showing other PDs. Psychoticism was more prevalent amongst the subjects showing depressive and schizotypal PDs. CONCLUSION: In order to verify the results of this preliminary study, which was carried out using a relatively small group of subjects, this work must be replicated using a larger and more representative group of subjects.

Cyclodextrin/chlorophyll a complexes as supramolecular photosensitizers.

The interactions between chlorophyll a, and three cyclodextrins, hydroxypropyl-beta-cyclodextrin heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin and hydroxypropyl-gamma-cyclodextrin, were studied in aqueous solutions by means of absorption, emission and circular dichroism spectroscopy. Nanosecond laser flash photolysis and steady-state singlet oxygen generation experiments were performed to clarify the photoactivity of chlorophyll a in these systems. Moreover the photosensitizing activity of these complexes towards human leukemia T-lymphocytes (Jurkat cells) was tested and compared with that of the free sensitizer, chlorophyll a. The results obtained indicate that each cyclodextrin is able to carry the pigment in monomeric form inside of cells producing singlet oxygen.

Photoelectrochemical study on photosynthetic pigments-sensitized nanocrystalline ZnO films.

Hetero-structures formed by quantum-sized ZnO nanocrystals and photosynthetic pigments were prepared by adsorbing either chlorophyll a, carotenoids or their mixture onto a film of organic-capped ZnO nanoparticles. Photoelectrochemical measurements were comparatively performed on both bulk and nanocrystalline ZnO films after dye-covering in order to probe the photosensitization process occurring at the hetero-junction. The photoconversion process was found to be greatly enhanced at the nanocrystalline electrodes upon sensitization with a dye mixture. The sensitization process is discussed on the basis of the aggregation state of chlorophyll a, and of the specific photoprotective action played by carotenoids.

Spectroscopic and electrochemical study of Rose Bengal in aqueous solutions of cyclodextrins.

The interaction of Rose Bengal (RB) in aqueous solution of LiClO4 0.1 M with alpha-cyclodextrin (alpha-CD), hydroxypropyl-beta-cyclodextrins (HP-beta-CD) and hydroxypropyl-gamma-cyclodextrins (HP-gamma-CD) were studied by spectrophotometric measurements. The presence of Induced Circular Signals and the results of the analysis of the modifications in the absorbance spectra of RB produced by the presence of CDs in solution indicate that RB forms inclusion complexes only with HP-beta-CD and with HP-gamma-CD.

Methotrexate in the treatment of systemic glucocorticoid-dependent severe persistent asthma: a word of caution.

Methotrexate should not be prescribed to every systemic glucocorticoid-dependent asthmatic. In fact, while methotrexate may be advantageous in selected patients, every attempt to control asthma with regular anti-asthma agents should be made. Most studies on the effects of methotrexate in the treatment of systemic glucocorticoid-dependent asthmatics include small numbers of patients and are all of relatively short duration. Thus, large long-term multicentre trials are urgently needed. In these studies, a uniform accepted definition of systemic glucocorticoid-dependent asthmatics should be used. For the time being, we reinforce the recommendation of the NHLBI/ WHO panel that methotrexate and other systemic glucocorticoid sparing drugs should be considered experimental medications, and used only in selected patients under the supervision of an asthma specialist with previous experimental experience.