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There is currently substantial interest in commercializing perovskite solar cells as they offer superior properties over silicon-based solar cells, such as ability for bandgap tuning, higher absorption coefficients, and potentially lower manufacturing costs. However, trap states originating from ionic vacancies, imperfect interfaces, and grain boundaries have hampered their performance and long-term stability during operation. Identifying and quantifying defects in perovskite solar cells becomes inevitable to address these challenges and mitigate the deteriorating effects of these defects. This Review focuses on recent developments in optical and electrical characterization techniques employed for the investigation of defects in halide perovskites and the techniques to understand ion migration in devices. We focus on sample preparation, advantages, limitations, and the nature of information obtained from each of the spectroscopic techniques. This Review will enable the researchers to understand and identify suitable characterization techniques for characterizing defect concentrations and their energetic and spatial distribution in perovskite solar cells. There is great interest in commercializing perovskite solar cells, however, the presence of defects and trap states hinder their performance. Here, recent developments in characterization techniques to investigate defects and ion migration in halide perovskites are reviewed.

Ultrafast plasma dynamics play a pivotal role in the relativistic high harmonic generation, a phenomenon that can give rise to intense light fields of attosecond duration. Controlling such plasma dynamics holds key to optimize the relevant sub-cycle processes in the high-intensity regime. Here, we demonstrate that the optimal coherent combination of two intense ultrashort pulses centered at two-colors (fundamental frequency, ω and second harmonic, 2 ω ) can lead to an optimal shape in relativistic intensity driver field that yields such an extraordinarily sensitive control. Conducting a series of two-dimensional (2D) relativistic particle-in-cell (PIC) simulations carried out for currently achievable laser parameters and realistic experimental conditions, we demonstrate that an appropriate combination of ω - 2 ω along with a precise delay control can lead to more than three times enhancement in the resulting high harmonic flux. Finally, the two-color multi-cycle field synthesized with appropriate delay and polarization can all-optically suppress several attosecond bursts while favourably allowing one burst to occur, leading to the generation of intense isolated attosecond pulses without the need of any sophisticated gating techniques.

To meet the demands of the chemical and pharmaceutical process industry for a combination of high measurement accuracy, product selectivity, and low cost of ownership, the existing measurement and evaluation methods have to be further developed. This paper demonstrates the attempt to combine future Raman photometers with promising evaluation methods. As part of the investigations presented here, a new and easy-to-use evaluation method based on a self-learning algorithm is presented. This method can be applied to various measurement methods and is carried out here using an example of a Raman spectrometer system and an alcohol-water mixture as demonstration fluid. The spectra’s chosen bands can be later transformed to low priced and even more robust Raman photometers. The evaluation method gives more precise results than the evaluation through classical methods like one primarily used in the software package Unscrambler. This technique increases the accuracy of detection and proves the concept of Raman process monitoring for determining concentrations. In the example of alcohol/water, the computation time is less, and it can be applied to continuous column monitoring.

Nematode parasites infect approximately 1.5 billion people globally and are a significant public health concern. There is an accepted need for new, more effective anthelmintic drugs. Nicotinic acetylcholine receptors on parasite nerve and somatic muscle are targets of the cholinomimetic anthelmintics, while glutamate-gated chloride channels in the pharynx of the nematode are affected by the avermectins. Here we describe a novel nicotinic acetylcholine receptor on the nematode pharynx that is a potential new drug target. This homomeric receptor is comprised of five non-α EAT-2 subunits and is not sensitive to existing cholinomimetic anthelmintics. We found that EAT-18, a novel auxiliary subunit protein, is essential for functional expression of the receptor. EAT-18 directly interacts with the mature receptor, and different homologs alter the pharmacological properties. Thus we have described not only a novel potential drug target but also a new type of obligate auxiliary protein for nAChRs.

BackgroundThe Jagiellonian Positron Emission Tomograph is the 3-layer prototype of the first scanner based on plastic scintillators, consisting of 192 half-metre-long strips with readouts at both ends. Compared to crystal-based detectors, plastic scintillators are several times cheaper and could be considered as a more economical alternative to crystal scintillators in future PETs. JPET is also a first multi-photon PET prototype. For the development of multi-photon detection, with photon characterized by the continuous energy spectrum, it is important to estimate the efficiency of J-PET as a function of energy deposition. The aim of this work is to determine the registration efficiency of the J-PET tomograph as a function of energy deposition by incident photons and the intrinsic efficiency of the J-PET scanner in detecting photons of different incident energies. In this study, 3-hit events are investigated, where 2-hits are caused by 511 keV photons emitted in e+e- annihilations, while the third hit is caused by one of the scattered photons. The scattered photon is used to accurately measure the scattering angle and thus the energy deposition. Two hits by a primary and a scattered photon are sufficient to calculate the scattering angle of a photon, while the third hit ensures the precise labeling of the 511 keV photons.ResultsBy comparing experimental and simulated energy distribution spectra, the registration efficiency of the J-PET scanner was determined in the energy deposition range of 70–270 keV, where it varies between 20 and 100%. In addition, the intrinsic efficiency of the J-PET was also determined as a function of the energy of the incident photons.ConclusionA method for determining registration efficiency as a function of energy deposition and intrinsic efficiency as a function of incident photon energy of the J-PET scanner was demonstrated. This study is crucial for evaluating the performance of the scanner based on plastic scintillators and its applications as a standard and multi-photon PET systems. The method may be also used in the calibration of Compton-cameras developed for the ion−beam therapy monitoring and simultaneous multi-radionuclide imaging in nuclear medicine.

Cold-inducible RNA-binding protein (CIRP) is a versatile RNA-binding protein, pivotal in modulating cellular responses to diverse stress stimuli including cold shock, ultraviolet radiation, hypoxia, and infections, with a principal emphasis on cold stress. The temperature range of 32–34 °C is most suitable for CIRP expression. The human CIRP is an 18–21 kDa polypeptide containing 172 amino acids coded by a gene located on chromosome 19p13.3. CIRP has an RNA-recognition motif (RRM) and an arginine-rich motif (RGG), both of which have roles in coordinating numerous cellular activities. CIRP itself also undergoes conformational changes in response to diverse environmental stress. Transcription factors such as hypoxia-inducible factor 1 alpha and nuclear factor-kappa B have been implicated in coordinating CIRP transcription in response to specific stimuli. The potential of CIRP to relocate from the nucleus to the cytoplasm upon exposure to different stimuli enhances its varied functional roles across different cellular compartments. The different functions include decreasing nutritional demand, apoptosis suppression, modulation of translation, and preservation of cytoskeletal integrity at lower temperatures. This review explores the diverse functions and regulatory mechanisms of CIRP, shedding light on its involvement in various cellular processes and its implications for human health and disease.

Reported herein is a summary of the reductive amination of carbonyls as a facile strategy for the synthesis of amines. The history, applications, and chemical properties of various frequently utilized reductive amination reagents have been described providing an insight into the significance of chemoselectivity of the reducing agent in achieving an effective protocol. The key to a successful reductive amination is the ability of the reducing agent to selectively reduce imines in the presence of the carbonyl starting material. Utilizing the recent advances in synthetic methodologies for obtaining amine-boranes and their versatility for selective reductions, amine-boranes and their derivatives have been explored for developing improved reductive amination procedures. First, Ammonia-borane is described as an accessible, air-and moisture-stable, and atom-economical reducing agent which provides amines in high-to-excellent yields in the presence of sub-stoichiometric trimethyl borate as a Lewis acid promoter. This solvent-free route is environment-friendly with a low process mass intensity and has been demonstrated to perform at a mole scale. While the substrate scope of this procedure extends to the amination of aldehydes and ketones with aliphatic and aromatic amines, a two-step indirect approach is necessary in the case of challenging substrates. These include (i) aryl ketones, (ii) deactivated anilines, and (iii) aldehydes with 2°-amines due to the sluggish generation of imines and competitive reduction of carbonyl. To address these limitations, amine-boranes are modified via reaction with trifluoroacetic acid to provide novel monotrifluoroacetoxyborane-amine (TFAB-amine) complexes. This new class of reagents serves as mild and highly chemoselective agents for the direct reductive amination of aldehydes and ketones. Among these, TFAB-NEt3 is established as superior, compared to widely used reductive amination reagents, providing improved yields even for challenging substrates. The application of the monotrifluoroacetoxyborane-derivatives has been extended for the synthesis of lactams from keto-acids and amino-acids via a tandem reductive amination-amidation protocol.

Glutamate-gated chloride channels (GluCls) are unique to invertebrates and are targeted by macrocyclic lactones. In this study, we cloned an AVR-14B GluCl subunit from adult Brugia malayi, a causative agent of lymphatic filariasis in humans. To elucidate this channel’s pharmacological properties, we used Xenopus laevis oocytes for expression and performed two-electrode voltage-clamp electrophysiology. The receptor was gated by the natural ligand L-glutamate (effective concentration, 50% [EC50 ] = 0.4 mM) and ivermectin (IVM; EC50 = 1.8 nM). We also characterized the effects of nodulisporic acid (NA) on Bma-AVR-14B and NA-produced dual effects on the receptor as an agonist and a type II positive allosteric modulator. Here we report characterization of the complex activity of NA on a nematode GluCl. Bma-AVR-14B demonstrated some unique pharmacological characteristics. IVM did not produce potentiation of L-glutamate–mediated responses but instead, reduced the channel’s sensitivity for the ligand. Further electrophysiological exploration showed that IVM (at a moderate concentration of 0.1 nM) functioned as an inhibitor of both agonist and positive allosteric modulatory effects of NA. This suggests that IVM and NA share a complex interaction. The pharmacological properties of Bma-AVR-14B indicate that the channel is an important target of IVM and NA. In addition, the unique electrophysiological characteristics of Bma-AVR-14B could explain the observed variation in drug sensitivities of various nematode parasites. We have also shown the inhibitory effects of IVM and NA on adult worm motility using Worminator. RNA interference (RNAi) knockdown suggests that AVR-14 plays a role in influencing locomotion in B. malayi.

Diabetic complications are associated with the glycation and formation of advanced glycation end products (AGEs) which leads to structural modifications of biomolecules further affecting cells. Carbonyl compounds such as methylglyoxal and glyceraldehyde-3-phosphate are highly reactive and form an elevated amount of AGEs as compared to glucose and fructose. The investigation of glycation modifications by different compounds may be important to assess the specific pattern of biomolecular and cellular modifications and compare their glycation potential. The present work aims to comprehensively and comparatively examine the effect of glycating agents (glucose, fructose, ribose, methylglyoxal, and glyceraldehyde) on plasma, erythrocytes, platelets, and blood DNA. Glycation of plasma, cells, and DNA was initiated by incubating them with glycating agents for 24–48 h at 37 °C. Negative control samples (without glycating agents) were maintained simultaneously. After treatment, plasma and DNA samples were dialyzed and cell lysate was prepared. Markers of glycation (fructosamine), structural modifications (free amino, β-amyloid, absorption spectra), antioxidant indices (catalase activity, glutathione) and erythrocyte hemolysis were estimated. In the presence of glycating agents, there was a significant increase in the formation of fructosamine, structural modification markers and depletion in antioxidant indices. Overall results suggest that among all glycating agents; methylglyoxal and glyceraldehyde have more potency of glycation induced structural modifications in plasma and vascular cells. This indicates the specific glycation modifications in plasma and vascular cells by various glycating agents may be investigated further for controlling diabetic pathological changes.

Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of 10 −4 signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation. Positronium decay events can be used to test violation of fundamental symmetries. Here, the authors use events in the J-PET to improve existing limits on P, T and CP invariance in positronium decays, thanks to a method that does not require to measure the positronium spin but determining polarization of the annihilation photons instead.