Novel Azocoumarin Derivatives—Synthesis and Characterization

The paper presents synthesis and characterization of nine new thiazolyl-(phenyldiazenyl)-2H-chromen-2-one dyes. The impact of substituent structure in thiazole ring in the synthesized azocoumarin derivatives on electrochemical properties, photoisomerization process and photovoltaic response was examined. The dyes were electrochemically active and undergo reduction and oxidation processes. They showed low electrochemically estimated energy band gap in the range of 1.71–2.13 eV. Photoisomerization process of the synthesized molecules was studied in various solvents such as ethanol, chloroform and N,N-dimethylformamide (DMF) upon the UV illumination. It was found that novel azodyes showed reversible trans-cis-trans isomerization and exhibited long thermal back to the trans form, that was even 7 days in DMF. Selected azocoumarin were molecularly dispersed in polystyrene for preparation of guest-host azopolymer systems to study the cis-trans thermal isomerization of obtained dyes in solid state. The photovoltaic activity of the azochromophores was tested in bulk-heterojunction solar cells. They acting as weak donors in device with structure ITO/PEDOT:PSS/dye:PC70BM/Al. No photovoltaic response of cells with azocoumarin derivatives bearing 4-fluorobenzene, 3,4-dichlorobenzene, or 4-(1-adamantyl) unit was found. Additionally, dye which showed the best activity was examined in three-component solar cells ITO/PEDOT:PSS/PTB7:PC70BM:dye/PFN/Al.     

Eigenschaften und thermische Reaktionen von Komplexen der Arendiazoniumsalze mit Kronenethern

Properties and Thermal Reactions from Complexes of Arene Diazonium Salts with Crown Ethers In contrast to 18-crown-6, the substituted crown ethers Benzo-18-crown-6, Dibenzo-18-crown-6, and Naphtho-18-crown-6 form in solution complexes with p-CH₃ C₆H₄ N₂⁺BF₄-characterized by a broad charge transfer absorption up to 550 nm. The formation constants lg K_c are 2,32 2,16 and 1,44 for Benzo-, Dibenzo-, and Naphtho-18-crown-6, respectively. Formation enthalpy ΔH = −7,5 kJ/mol and entropy ΔS = +18 J/K mol are measured in the case of p-Cl C₆H₄ N₂⁺BF₄⁻ and Dibenzo-18-crown-6 (20°). K_c depends on substituents in the arene ring of the diazonium salt; ϱ = +0,8. Thermal dediazoniation in the presence of Crown ethers results in high yields of the corresponding arene. This is explained by a fast radical chain reaction between the diazonium salt and the polyether (Meerwein-Reduction).     

Characterisation of Trichomonas vaginalis Isolates Collected from Patients in Vienna between 2019 and 2021

Trichomonas vaginalis (TV) is the causative agent of trichomoniasis, the most common nonviral sexually transmitted disease. TV can carry symbionts such as Trichomonas vaginalis virus (TVV) or Mycoplasma hominis. Four distinct strains of TV are known: TVV1, TVV2, TVV3, and TVV4. The aim of the current study was to characterise TV isolates from Austrian patients for the presence of symbionts, and to determine their effect on metronidazole susceptibility and cytotoxicity against HeLa cells. We collected 82 TV isolates and detected presence of TVV (TVV1, TVV2, or TVV3) in 29 of them (35%); no TVV4 was detected. M. hominis was detected in vaginal/urethral swabs by culture in 37% of the TV-positive patients; M. hominis DNA was found in 28% of the TV isolates by PCR. In 15% of the patients, M. hominis was detected in the clinical samples as well as within the respective TV isolates. In 22% of the patients, M. hominis was detected by culture only. In 11 patients, M. hominis was detected only within the respective cultured TV isolates (13%), while the swab samples were negative for M. hominis. Our results provide a first insight into the distribution of symbionts in TV isolates from Austrian patients. We did not observe significant effects of the symbionts on metronidazole susceptibility, cytotoxicity, or severity of symptoms.     

Morphology and properties of foamed high crystallinity PEEK prepared by high temperature thermally induced phase separation

Polyetheretherketone (PEEK) is a high-performance semi-crystalline thermoplastic polymer with outstanding mechanical properties, high thermal stability, resistance to most common solvents, and good biocompatibility. A high temperature thermally induced phase separation technique was used to produce PEEK foams with controlled foam density from PEEK in 4-phenylphenol (4PPH) solutions. Physical and mechanical properties, foam and bulk density, surface area, and pore morphology of foamed PEEK were characterized and the role of PEEK concentration and cooling rate was investigated. Porous PEEK with densities ranging from 110 to 360 kg/m³ with elastic moduli and crush strength ranging from 13 to 125 MPa and 0.8 to 7 MPa, respectively, was produced.     

Assessment of Tailor-Made HPMC-Based Matrix Minitablets Comprising a Weakly Basic Drug Compound

Tailor-made, pH-controlled matrix minitablets based on different HPMC types were developed comprising the weakly basic drug dipyridamole. The incorporation of pH modifiers, i.e., fumaric and succinic acid, enhanced the drug release at pH 6.8. Assessing the drug release, acid release, and the microenvironmental pH (pH_M) provided detailed understanding of pH-controlled mini-matrices.

The extent and duration of pH_M alteration was more pronounced in presence of fumaric acid. Minitablets based on the fast dissolving Methocel K100LV (≤ 100 cps) showed simultaneous release rates of dipyridamole and fumaric acid with a constant low average pH_M.     

Session and intersession experience related to treatment outcome in bulimia nervosa.

Treatment in bulimia nervosa is challenging, with rates of successful treatments for only about 50% of all patients. This study aimed to identify predictors of outcome through secondary analysis of data from a randomized clinical trial that compared inpatient and day hospital treatment for bulimia. Process measures included assessments of patients' in-session experiences, therapeutic alliance, and therapy-related intersession experiences (ISE). ISE measures were better predictors of outcome than pretreatment variables (e.g., social adjustment) or global therapeutic alliance. Outcome at 3 month follow-up was strongly related to the ISE dimension Recreating Therapeutic Dialogue with Negative Emotions, indicating a heightened risk of failure. Prediction of outcome by these variables showed a sensitivity of 0.86 and a specificity of 0.78, and 83% of patients could be correctly classified. These results show that certain aspects of ISE may serve as early and reliable indicators of long term treatment failure, prompting alternate treatment approaches and opening new directions of research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of civil war: scientific cooperation in the republics of the former Yugoslavia and the province of Kosovo

In this study we investigate the scientific output of Yugoslavia and its successor republics viz. Serbia, Croatia, Slovenia, Bosnia & Herzegovina, Macedonia and Montenegro. Additionally, Kosovo was included as a separate entity, since it recently declared its independence. The publications and cooperation between the republics are analyzed for the years from 1970 until 2007. In contrast to similar studies, we examine a larger time window and take into consideration not only the three big republics (Serbia, Croatia, and Slovenia) but also include the smaller ones, namely Bosnia & Herzegovina, Macedonia and Montenegro. For our analysis we introduce two new indicators: the normalized cooperation score (R^(cs)_iR^{\rm (cs)}_{i}) and the dominance factor (D^(c)_iD^{\rm (c)}_{i}), a measure of dominance within a weighted network. Furthermore, we develop and assess the reliability of various techniques for visualizing our findings. We found that the civil wars had a severe impact on the inner-Yugoslav cooperation network. Additionally it seems, as if with the ending of the conflicts a process of recovery started.     

State-of-the art comparability of corrected emission spectra. 1. Spectral correction with physical transfer standards and spectral fluorescence standards by expert laboratories

The development of fluorescence applications in the life and material sciences has proceeded largely without sufficient concern for the measurement uncertainties related to the characterization of fluorescence instruments. In this first part of a two-part series on the state-of-the-art comparability of corrected emission spectra, four National Metrology Institutes active in high-precision steady-state fluorometry performed a first comparison of fluorescence measurement capabilities by evaluating physical transfer standard (PTS)-based and reference material (RM)-based calibration methods. To identify achievable comparability and sources of error in instrument calibration, the emission spectra of three test dyes in the wavelength region from 300 to 770 nm were corrected and compared using both calibration methods. The results, obtained for typical spectrofluorometric (0°/90° transmitting) and colorimetric (45°/0° front-face) measurement geometries, demonstrated a comparability of corrected emission spectra within a relative standard uncertainty of 4.2% for PTS- and 2.4% for RM-based spectral correction when measurements and calibrations were performed under identical conditions. Moreover, the emission spectra of RMs F001 to F005, certified by BAM, Federal Institute for Materials Research and Testing, were confirmed. These RMs were subsequently used for the assessment of the comparability of RM-based corrected emission spectra of field laboratories using common commercial spectrofluorometers and routine measurement conditions in part 2 of this series (subsequent paper in this issue).