Impact of Cesium Concentration on Optoelectronic Properties of Metal Halide Perovskites

Performance of a perovskite solar cell is largely influenced by the optoelectronic properties of metal halide perovskite films. Here we study the influence of cesium concentration on morphology, crystal structure, photoluminescence and optical properties of the triple cation perovskite film. Incorporation of small amount (x = 0.1) of cesium cations into Cs_x(MA_0.17FA_0.83)_1−x Pb(I_0.83Br_0.17)₃ leads to enhanced power conversion efficiency (PCE) of the solar cell resulting mainly from significant rise of the short-current density and the fill factor value. Further increase of Cs concentration (x > 0.1) decreases the film’s phase purity, carrier lifetime and correspondingly reduces PCE of the solar cell. Higher concentration of Cs (x ≥ 0.2) causes phase segregation of the perovskite alongside with formation of Cs-rich regions impeding light absorption.     

Immobilization of Hexavalent Chromium Using Self-Compacting Soil Technology

A study of immobilization of hexavalent chromium in the form of Na₂CrO₄ salt by self-compacting soils (SCS) is presented. Carbofill E additive was used as SCS binder. The efficiency of immobilization of Cr (VI) was evaluated by washing out chromium compounds from SCS samples. The influence of the nature of the soil and the content of Carbofill E and Na₂CrO₄ in the SCS samples on the efficiency of Cr (VI) immobilization was studied. It was found that the nature of the soil and the content of Carbofill E in the SCS samples affect the immobilization of Cr (VI). Moreover, increasing the Carbofill E content in SCS samples further increases Cr (VI) immobilization. X-ray diffraction studies of the samples with immobilized hexavalent chromium showed that part of the sample transforms from a readily soluble form of salt into oxide forms of chromium and calcium-chromium, which are practically insoluble in water.     

Classification analysis of P-glycoprotein substrate specificity

Prediction of P-glycoprotein substrate specificity (S(PGP)) can be viewed as a constituent part of a compound's "pharmaceutical profiling" in drug design. This task is difficult to achieve due to several factors that raised many contradictory opinions: (i) the disparity between the S(PGP) values obtained in different assays, (ii) the confusion between Pgp substrates and inhibitors, (iii) the confusion between lipophilicity and amphiphilicity of Pgp substrates, and (iv) the dilemma of describing class-specific relationships when Pgp has no binding sites of high ligand specificity. In this work, we compiled S(PGP) data for 1000 compounds. All data were represented in a binary format, assigning S(PGP) = 1 for substrates and S(PGP) = 0 for non-substrates. Each value was ranked according to the reliability of experimental assay. Two data sets were considered. Set 1 included 220 compounds with S(PGP) from polarized transport across MDR1 transfected cell monolayers. Set 2 included the entire list of 1000 compounds, with S(PGP) values of generally lower reliability. Both sets were analysed using a stepwise classification structure-activity relationship (C-SAR) method, leading to derivation of simple rules for crude estimation of S(PGP) values. The obtained rules are based on the following factors: (i) compound's size expressed through molar weight or volume, (ii) H-accepting given by the Abraham's beta (that can be crudely approximated by the sum of O and N atoms), and (iii) ionization given by the acid and base pKa values. Very roughly, S(PGP) can be estimated by the "rule of fours". Compounds with (N + O) > or = 8, MW > 400 and acid pKa > 4 are likely to be Pgp substrates, whereas compounds with (N + O) < or = 4, MW < 400 and base pKa < 8 are likely to be non-substrates. The obtained results support the view that Pgp functioning can be compared to a complex "mini-pharmacokinetic" system with fuzzy specificity. This system can be described by a probabilistic version of Abraham's solvation equation, suggesting a certain similarity between Pgp transport and chromatographic retention. The chromatographic model does not work in the case of "marginal" compounds with properties close to the "global" physicochemical cut-offs. In the latter case various class-specific rules must be considered. These can be associated with the "amphiphilicity" and "biological similarity" of compounds. The definition of class-specific effects entails construction of the knowledge base that can be very useful in ADME profiling of new drugs.     

Innervation of pulmonary veins: Morphologic pattern and pathways of nerves in the human fetus

The aim of the study was to determine the anatomy of intrinsic nerves supplying human pulmonary veins (PVs). Twenty-two hearts of human fetuses with full sets of PVs were examined using a histochemical method for acetylcholinesterase in order to stain transmurally intrinsic neural structures on non-sectioned PVs for subsequent stereomicroscopic examination. Findings of the study demonstrate that epicardiac nerve extensions from both the dorsal right atrial and the middle dorsal subplexuses reached the right superior as well as the right inferior PVs, whereas the left superior PV was supplied by nerve extensions from the left dorsal subplexus. The left and middle dorsal subplexuses contributed nerves to the left inferior PV. The ganglia related topographically to PVs were patchy in distribution. On the left and right superior PVs, 38±6 and 31±3 ganglia were found, respectively, whereas 46±7 and 38±7 ganglia were identified on the left and right inferior PVs. The size of ganglia was similar for all four veins, ranging in area from 0.004±0.0003 to 0.007±0.0004 mm². The total area of ganglia distributed on a given PV was similar, ranging from 0.15±0.0003 to 0.25±0.0004 mm². The present findings demonstrate that the richest ganglion sites supplying intrinsic nerves to the human PVs are located on the posterior sides of both inferior and the left superior PVs and, therefore, these sites may be considered primary targets for focal pulmonary vein ablation in catheter-based therapy of atrial fibrillation.     

Ionization-specific analysis of human intestinal absorption

This study presents a mechanistic QSAR analysis of human intestinal absorption of drugs and drug-like compounds using a data set of 567 %HIA values. Experimental data represent passive diffusion across intestinal membranes, and are considered to be reasonably free of carrier-mediated transport or other unwanted effects. A nonlinear model was developed relating %HIA to physicochemical properties of drugs (lipophilicity, ionization, hydrogen bonding, and molecular size). The model describes ion-specific intestinal permeability of drugs by both transcellular and paracellular routes, and also accounts for unstirred water layer effects. The obtained model was validated on two external data sets consisting of in vivo human jejunal permeability coefficients (P_eff) and absorption rate constants (K_a). Validation results demonstrate good predictive power of the model (RMSE = 0.35–0.45 log units for log K_a and log P_eff). High prediction accuracy together with clear physicochemical interpretation (log P, pK_a) makes this model particularly suitable for use in property-based drug design. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4039–4054, 2009     

A double-orifice tricuspid valve associated with a divided right atrium

Right atrioventricular valve duplication is a rare congenital anomaly with only isolated cases of a double-orifice tricuspid valve having been described. This article presents a case of the surgical repair of a double-orifice tricuspid valve associated with a divided right atrium, a ventricular septal defect, and Wolff-Parkinson-White syndrome.     

Status of occupational cancer in Lithuania

Because industrialization in Lithuania started only about 50 years ago, occupational cancer is only now becoming an important issue. This article describes the situation of occupational cancer in Lithuania: research, exposures to carcinogens, regulation, and legal practice. Epidemiologic studies of work-related cancers have shown increased risks among cement, textile, and asbestos-cement workers. In 1997, 28% of employed workers in Lithuania were exposed to carcinogens. A legislation system regulating exposures to carcinogens, harmonized with European Directives, has recently been created. In 1995-2003, there were 5,652 new cases of occupational diseases. However, occupational cancers are seriously underdiagnosed--only one case of cancer was diagnosed as occupational. Establishment of a system that would enable diagnosis, certification, and compensation of cases of occupational neoplasms is essential in Lithuania.     

Clinically equivalent bronchodilatation achieved with formoterol delivered via Easyhaler and Aerolizer

BACKGROUND: User-friendly devices for the delivery of asthma drugs are needed to enhance treatment compliance. Formoterol inhalation powder has been developed to Easyhaler multidose powder inhaler to enable the treatment of all asthma severities with the same device. OBJECTIVES: This double-blind, double-dummy, single- dose, placebo-controlled, cross-over study aimed to demonstrate the non-inferiority of the bronchodilating effect of formoterol 12 microg delivered via Easyhaler versus via Aerolizer. In addition, dose responses following placebo, 12-microg and 48-microg doses of formoterol via Easyhaler were compared. Furthermore, onset and duration of action, and safety of formoterol inhaled using the two inhalers were compared. METHODS: Sixty-seven adult asthmatic subjects showing >or=15% increase in forced expiratory volume in 1 s (FEV(1)) after short-acting sympathomimetic inhalation were enrolled and completed the study. The study comprised screening and 4 treatment days, with each subject inhaling a single 12-mug dose of formoterol via Easyhaler, a 12-microg dose via Aerolizer, a 48-microg dose via Easyhaler or placebo. Repeat spirometry and vital sign measurements were performed for 12 h during treatment days. The primary efficacy variable was the area under the flow volume curve (AUC(0-12)) of FEV(1). Secondary efficacy variables comprised maximum FEV(1 )(FEV(1max)), forced vital capacity (FVC), and the need of rescue medication during the treatment days. Safety was evaluated by determining blood pressure, heart rate and the number of adverse events (AEs). RESULTS: Results showed the non-inferiority of the bronchodilating effect of 12 microg formoterol via Easyhaler compared to Aerolizer. The Easyhaler-Aerolizer ratio for AUC(0-12) of FEV(1 )was 0.991 (95% confidence interval from 0.969 to 1.013). No statistically significant differences emerged for secondary efficacy variables. A statistically significant dose response was seen following placebo, 12- and 48-microg doses in FEV(1). No safety differences emerged for the 12-microg dose inhaled via Easyhaler or Aerolizer, but the incidence of AEs was higher following formoterol 48 microg and placebo treatments. CONCLUSIONS: Formoterol delivered via Easyhaler was therapeutically equivalent to Aerolizerat the 12-microg dose. The 48-microg dose via Easyhaler demonstrated statistically significantly greater bronchodilation but showed an increased occurrence of AEs.