Synergistic Zinc(II) and Formate Doping of Perovskites: Thermal Phase Stabilization of α-FAPbI3 and Enhanced Photoluminescence Lifetime of FA0.8MA0.2PbI3 up to 3.7 µs.

Adding zinc (II) cations and formate anions improves the thermal phase stability of α-FAPbI3 materials, and the spin-coated thin films of such doped FAPbI3 (produced using MACl) show an increased emission lifetime of up to 3.7 µs on quartz (for FA0.8MA0.2PbI3). This work investigates the effects of zinc and formate on the phase stability and time-resolved photoluminescence of FAPbI3 perovskites for solar cell applications. Perovskite samples with varying concentrations of zinc and formate were made by incorporating different amounts of zinc formate and zinc iodide and were characterized with XRD. Doping levels of 1.7% Zn(II) and 1.0% formate (relative to Pb) seem optimal. The thermal phase stability of the doped perovskite powders (FAPbI3) and thin films (FA0.8MA0.2PbI3) was assessed. XRD of the thin films after 6 months shows only the alpha-phase. The time-resolved photoluminescence spectroscopy of the doped spin-coated perovskite samples (FA0.8MA0.2PbI3 produced using MACl) is reported. The results show that synergy between an anionic and a cationic dopant can take place, making the perovskite thermally more phase-stable (not converting to the yellow delta-phase) with a longer charge carrier lifetime. In order to produce good thin films by spin coating, the use of MACl was essential.

[Video-based teaching in pathology. Experience gained in the last 3 years at the RWTH Aachen University]. / Videobasierte Lehre der Pathologie. Erfahrungen der letzten drei Jahre an der RWTH Aachen.

Modern computer technology provides students with easier access to learning materials. Basic knowledge of pathological findings in organs is essential in medical education. We have produced didactic videos for teaching pathology in a clinical context in addition to regular lectures at the university. Didactic material includes macroscopic and histological findings, as well as cartoons explaining pathophysiology and clinical links. Videos can be downloaded in mv4 format as podcasts to a local hard disk or to an iPhone or iPod via iTunes University and are designed to improve classical medical literature. Analysis over 3 years of server traffic and subjective impressions by the students revealed regular use and high acceptance by users. Didactic material in clinical pathology can be successfully integrated in videos to complement lectures and practical training. Modern teaching methods in pathology make the specialty more understandable and therefore more attractive for students.

[Speech rate of compensatory articulation in patients with cleft lip and palate]. / Sprechgeschwindigkeit bei kompensatorischer Artikulation von Patienten mit Lippen-Kiefer-Gaumenspalten.

Infolge eines primären Defizits der velopharyngealen Funktion liegen bei vielen Patienten mit Lippen-Kiefer-Gaumenspalten sekundäre kompensatorische Lautbildungen vor. Mit zwei neuen Computerprogrammen werden die Auswirkungen der kompensatorischen Artikulation auf die durchschnittliche Sprechgeschwindigkeit von 146 Patienten mit Lippen-Kiefer-Gaumen-spalten untersucht. Die Patienten wurden dabei nach dem Schweregrad der artikulatorischen Auffälligkeit gruppiert. Bei der schnellen Silbenwiederholung zeigte sich, dass die durchschnittliche Silbenrate pro Sekunde bei Patienten mit deutlich auffälliger Artikulation signifikant reduziert war. Beim Nachsprechen von Sätzen war die zum Nachsprechen benötigte Gesamtzeit bei dieser Patientengruppe signifikant erhöht, und das Zielwort des Satzes wurde signifikant später begonnen. Die Ergebnisse zeigen, dass die mittlere Sprechgeschwindigkeit von Patienten mit Lippen-Kiefer-Gaumenspalten mit kompensatorischer palatolalischer Artikulation niedriger ist.

Simple chemiluminescence assays for free radicals in venous blood and serum samples: results in atopic, psoriasis, MCS and cancer patients.

OBJECTIVE: To investigate the generation of reactive oxygen species (ROS) in serum and venous blood as well as the serum antioxidative activity (AOA) in patients and healthy controls by means of a simplified chemiluminescence (CL) methodology. STUDY PARTICIPANTS: 48 Atopic eczema, 23 psoriasis, 15 multiple chemical sensitivity (MCS) and 35 cancer patients together with 22 healthy volunteers. METHODS: ROS generation/photon emission in blood and serum samples under basal conditions and after light exposure as well as the AOA of the serum samples was investigated at room temperature (22 degrees C) in all 143 fasted subjects. The 3-step methodology resumes in adding a constant amount of blood or serum to a constant amount of CL substrate (or to an ROS-generating mixture for the AOA test), followed by a short preincubation and registration of the photon counts over a 600-second time interval. RESULTS: In the basal and light exposure tests significantly higher photon counts (> 14, 000 counts/600 s) were registered in venous blood in all patient groups when compared to healthy controls (p < 0.001), suggesting increased amounts of activated leukocytes and light-sensitizing compounds, respectively. By contrast, most patient sera showed in all three CL tests a strongly inhibited light emission (p < 0.005), suggesting an adaptive antioxidative response to oxidant stress factors. CONCLUSIONS: Atopic, psoriasis, MCS and cancer patients are exhibiting significantly changed blood and serum CL patterns when compared to healthy controls. The described assays are simple, well reproducible and enable a fast assessment of ROS generation and AOA in biological samples at low operational costs.

[Perceptive and instrumental examination of voice quality in patients with lip-jaw-palate clefts]. / Perzeptive und apparative Untersuchung der Stimmqualität bei Patienten mit Lippen-Kiefer-Gaumenspalten.

BACKGROUND: In Anglo-American literature, prevalences as high as 41% are reported for voice disorders in cleft lip and palate (CLP) patients. Because of considerable variability in the reported findings and because no prevalence data are available for the German-speaking area, a screening study was conducted. METHOD: 154 patients with CLP were examined. Voice quality was assessed perceptively according to the rbh-system (roughness, breathiness, hoarseness). Suprasegmentals and nasal resonance were also assessed. Using a new computer programme for the apparative analysis of voice quality, data for pitch, intensity and pertubation (jitter and shimmer) were obtained for 4 sustained vowels. RESULTS: Based on perceptual analysis, we found that the prevalence of severe voice disorders in CLP patients was 6.5% which is lower than reported in most other studies. The incidence of voice disorders in CLP patients is numerically only slightly higher than in the normal population. The acoustic measurements confirm the results of perceptual analysis. Since the prevalence of severe voice disorders was low, none of the pertubation quotients differentiated between modal and disordered voices. A weak correlation was found between jitter and the ratings for hoarseness. CONCLUSIONS: 1. While it is appropriate to assume a higher potential risk for vocal dysfunction in CLP patients the actual prevalence in the patients examined is numerically only slightly higher than in normals. 2. For patients with voice disorders, apparative diagnostics of voice quality is a useful and practical adjunct to perceptual analysis which helps profiling individual patients and helps the professional to make decisions for therapy.

The role of risk perception and efficacy cognitions in the prediction of HIV-related preventive behavior and condom use.

PIP: The salience of the Protection Motivation Theory to HIV preventive behavior was investigated in a sample of 468 heterosexual men 20-45 years of age recruited in Germany and at vacation spots in Spain. This theory conceptualizes self-protective behaviors as a function of the severity of the threat, perceived personal vulnerability to this threat, the availability of coping responses, and the effectiveness of these responses. Cognitive variables measured included perceived severity of the threat of AIDS, sexual self-efficacy expectancy, self-efficacy expectations in terms of sexual communication skills, response efficacy, and attitude toward condom use. On a scale of 1 (low) to 6 (high), perceived severity of the AIDS threat averaged 5.3, individual susceptibility ratings averaged 3.5, and susceptibility of peers had a mean of 4.9. Although 33% of respondents had made behavioral changes in response to the AIDS epidemic, only 15% always used condoms while 12% used them occasionally. Self-efficacy expectancy with regard to assertiveness and use of preventive measures emerged as the most significant predictor of HIV-related behaviors. The causal analyses indicated that high communicative self-efficacy expectancy is associated with high-risk sexual behaviors, while self-efficacy expectancy regarding assertiveness and the use of preventive measures promotes risk reduction. These associations were strongest in men over 26 years of age, singles, and tourists. These findings suggest a need for interventions for couples such as assertiveness training and guidance on communicating about sex and AIDS. Also demonstrated was the need for AIDS education programs to identify where participants are in terms of perceiving the threat of and coping with the AIDS epidemic and promote conditions that will help people advance to the next stage.^ieng