Diphenylamine‐Substituted Carbazole‐Based Hole Transporting Materials for Perovskite Solar Cells: Influence of Isomeric Derivatives

A series of new branched hole transporting materials (HTMs) containing two diphenylamine‐substituted carbazole fragments linked by a nonconjugated methylenebenzene unit is synthesized and tested in perovskite solar cells. Synthesis of the investigated materials is performed by a simple two‐step synthetic procedure providing a target product in high yield. The isolated materials demonstrate good thermal stability and majority of the investigated compounds exist in an amorphous state, which is advantageous as there is no risk of crystallization directly in the film. The highest charge drift mobility of µ₀ = 4 × 10^?4 cm² V^?1 s^?1, measured at weak electric fields, is by ca. one order of magnitude higher than that of Spiro‐OMeTAD under identical conditions. From the perovskite solar cell testing results, it can be seen that performance of two new HTMs ( V885 and V911 ) is on a par with Spiro‐OMeTAD. Due to the ease of synthesis, good thermal, optical and photophysical properties, this type of molecules hold great promise for practical application in commercial perovskite solar cells.     

In situ UV–VIS spectroelectrochemical study of polyaniline degradation

The degradation of polyaniline at anodic potentials was studied with in situ UV–Vis spectroscopy of polymer‐coated ITO glass electrodes. Spectral changes at high potential values were observed and discussed. Degradation follows first‐order kinetics, with rate constants ranging from 8.40 × 10⁻⁶ to 2.93 × 10⁻³ s⁻¹ at electrode potentials of E_NHE = +0.85 to +1.20 V. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 287–294, 1999     

A novel enzymatic method for the measurement of lactose in lactose-free products

The cover image is based on the Research Article A novel enzymatic method for the measurement of lactose in lactose-free products by David Mangan et al., DOI: 10.1002/jsfa.9317 . This cover was supported by Megazyme.

     

Cardiomyogenic Differentiation Potential of Human Dilated Myocardium-Derived Mesenchymal Stem/Stromal Cells: The Impact of HDAC Inhibitor SAHA and Biomimetic Matrices

Dilated cardiomyopathy (DCM) is the most common type of nonischemic cardiomyopathy characterized by left ventricular or biventricular dilation and impaired contraction leading to heart failure and even patients’ death. Therefore, it is important to search for new cardiac tissue regenerating tools. Human mesenchymal stem/stromal cells (hmMSCs) were isolated from post-surgery healthy and DCM myocardial biopsies and their differentiation to the cardiomyogenic direction has been investigated in vitro. Dilated hmMSCs were slightly bigger in size, grew slower, but had almost the same levels of MSC-typical surface markers as healthy hmMSCs. Histone deacetylase (HDAC) activity in dilated hmMSCs was 1.5-fold higher than in healthy ones, which was suppressed by class I and II HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) showing activation of cardiomyogenic differentiation-related genes alpha-cardiac actin (ACTC1) and cardiac troponin T (TNNT2). Both types of hmMSCs cultivated on collagen I hydrogels with hyaluronic acid (HA) or 2-methacryloyloxyethyl phosphorylcholine (MPC) and exposed to SAHA significantly downregulated focal adhesion kinase (PTK2) and activated ACTC1 and TNNT2. Longitudinal cultivation of dilated hmMSC also upregulated alpha-cardiac actin. Thus, HDAC inhibitor SAHA, in combination with collagen I-based hydrogels, can tilt the dilated myocardium hmMSC toward cardiomyogenic direction in vitro with further possible therapeutic application in vivo.     

PAHs in Indoor and Outdoor Air from Decentralized Heating Energy Production: Comparison of Active and Passive Sampling

Spatial and temporal variation of vapor- and particle-phase polycyclic aromatic hydrocarbons (PAHs) was determined in six urban and sub-urban locations in Kaunas, Lithuania during heating and non heating seasons. Two different sampling methodologies were used: passive (based on semipermeable membrane device, SPMD) and active (based on collection on filter and sorption). Sixteen priority PAHs as well as methylated PAHs were quantified in the collected samples. The sampled total amount of 16 PAHs investigated in SPMDs ranged from 10–138 ng/day outdoors, from 5–59 ng/day indoors during the winter sampling campaign. In summer these amounts varied from 11–19 ng/day outdoors and from 19–27 ng/day indoors. The total concentrations of vapor and particle-phase PAH in winter in actively taken samples varied from 49–286 ng/m³ outdoors and from 28–83 ng/m³ indoors. Seasonal differences as well as the influence of the fuel burning for domestic heating purposes on the PAH concentration outdoors were well reflected by the data obtained using the SPMD methodology.     

Decreased hemodialysis circuit pressures indicating postpump tubing kinks: a retrospective investigation of hemolysis in five patients

The source of hemolysis during hemodialysis must be quickly identified to avoid life-threatening complications. At a single clinic, over a 10-day period in which 550 treatments were performed, 5 case-patients were retrospectively identified for experiencing acute hemolysis (4 deaths) from an unknown origin. The investigation focused on the postpump arterial tubing as the pressure was not monitored in this region, and the segment was shorter than required and could kink if overly stressed at bend points (i.e., tubing support clips, dialyzer inlet). To determine whether the circuit pressures indicated kinked tubing, a relative comparison between each case-patient's recorded arterial (prepump) and venous circuit pressures throughout their adverse event treatment and their immediately preceding treatment was conducted. Treatment pressure-time traces showed that sustained, significant decreases (>25 mmHg) in both of the circuit pressures occurred only on the hemolytic event dates. While direct observations of kinked tubing were not reported, the circuit pressure decreases could only be explained by severe postpump tube kinking causing a decrease in the blood flow rate. While postpump obstructions and hemolysis can occur without causing noticeable changes to the prepump arterial and venous blood line pressures (due to the highly occlusive setting of the roller blood pump), recognizing sudden and/or sustained decreases in the circuit pressures during treatment may help to prevent adverse patient events. This analysis reinforces the importance of regularly checking the blood tubing set for kinks and for monitoring the circuit pressures for atypical trends within and between treatments.     

Dieting practices, weight perceptions, and body composition: A comparison of normal weight, overweight, and obese college females

Background  

Of concern to health educators is the suggestion that college females practice diet and health behaviors that contradict the 2005 dietary guidelines for Americans. In this regard, there remain gaps in the research related to dieting among college females. Namely, do normal weight individuals diet differently from those who are overweight or obese, and are there dieting practices used by females that can be adapted to promote a healthy body weight? Since it is well recognized that females diet, this study seeks to determine the dieting practices used among normal, overweight, and obese college females (do they diet differently) and identify dieting practices that could be pursued to help these females more appropriately achieve and maintain a healthy body weight.     

Part 1: A study on the properties of synthetic hydroxyledgrewite

In this work, for the first time chemical and physical properties of hydroxyledgrewite synthesized under hydrothermal conditions were examined. Hydroxyledgrewite was synthesized in the primary mixture consisted of CaO and amorphous SiO₂·nH₂O, when the molar ratio of CaO/SiO₂ was equal to 2.25. The synthesis has been carried out in unstirred suspensions under saturated steam pressure at 200°C temperature for 48 hours. It was proved that synthetic hydroxyledgrewite is stable till 675°C and at higher temperature recrystallized to γ‐C₂S, ‐C₂S, while upon subsequent cooling transformed into β‐C₂S. In addition to this, it was also determined that the density and specific heat capacity at 25°C are equal to 2.668 ± 5 g/cm³ and 0.928 J/(g·K), respectively. Synthetic hydroxyledgrewite showed disordered aggregates of plate‐like particles, while calculated S_BET value is equal to 13.961 m²/g. According gas adsorption results, it was obtained that hydroxyledgrewite is a mesoporous material. Also, it was obtained that after 72 hours of activated hydroxyledgrewite hydration, the amount of released heat was equal to 74.34 J/g. The product of synthesis and calcination were characterized by XRD, STA, DSC, SEM, TEM, FT‐IR analyses, and BET method.     

Two-Photon Polymerization Lithography for Optics and Photonics: Fundamentals,Materials, Technologies,and Applications

The rapid development of additive manufacturing has fueled a revolution in various research fields and industrial applications. Among the myriad of advanced 3D printing techniques, two-photon polymerization lithography (TPL) uniquely offers a significant advantage in nanoscale print resolution, and has been widely employed in diverse fields, for example, life sciences, materials sciences, mechanics, and microfluidics. More recently, by virtue of the optical transparency of most of the resins used, TPL is finding new applications in optics and photonics, with nanometer to millimeter feature dimensions. It enables the minimization of optical elements and systems, and exploration of light-matter interactions with new degrees of freedom, never possible before. To review the recent progress in the TPL related optical research, it starts with the fundamentals of TPL and material formulation, then discusses novel fabrication methods, and a wide range of optical applications. These applications notably include diffractive, topological, quantum, and color optics. With a panoramic view of the development, it is concluded with insights and perspectives of the future development of TPL and related potential optical applications.     

Fabrication of Glass-Ceramic 3D Micro-Optics by Combining Laser Lithography and Calcination

This perspective is an overview of a recent direction in optical 3D printing, where polymerization of crosslinkable materials and nanomaterial fillers can be guided to the final structures and new composites via high temperature annealing (HTA). Defining 3D nano/micro-structures by ultrafast laser direct writing and tailoring their precursor composition with subsequent tunability of the final properties during 750–1500 °C HTA step takes place at the large surface-to-volume ratio conditions favoring efficient pyrolysis and calcination, which are required for exchange of chemical materials/gases between glass/ceramic phase and surrounding. Previously, unexplored inorganic material formation conditions in terms of fast thermal quenching, composition mixing and surface tension guided formation can be harnessed by glass making for creation of new materials endowed with preferable technical properties. An immediate application perspective for a high durability, integrated, and active 3D micro-optics is foreseen.