Blue phase liquid crystals (BPLCs) are chiral mesophases with 3D order, which makes them a promising template for doping nanoparticles (NPs), yielding tunable nanomaterials attractive for microlasers ...and numerous microsensor applications. However, doping NPs to BPLCs causes BP lattice extension, which translates to elongation of operating wavelengths of light reflection. Here, it is demonstrated that small (2.4 nm diameter) achiral gold (Au) NPs decorated with designed LC-like ligands can enhance the chiral twist of BPLCs (i.e., reduce cell size of the single BP unit up to ∼14% and ∼7% for BPI and BPII, respectively), translating to a blue-shift of Bragg reflection. Doping NPs also significantly increases the thermal stability of BPs from 5.5 °C (for undoped BPLC) up to 22.8 °C (for doped BPLC). In line with our expectations, both effects are saturated, and their magnitude depends on the concentration of investigated nanodopants as well the BP phase type. Our research highlights the critical role of functionalization of Au NPs on the phase sequence of BPLCs. We show that inappropriate selection of surface ligands can destabilize BPs. Our BPLC and Au NPs are photochemically stable and exhibit great miscibility, preventing NP aggregation in the BPLC matrix over the long term. We believe that our findings will improve the fabrication of advanced nanomaterials into 3D periodic soft photonic structures.
The paper presents 3D numerical analysis results on the effect of bulk solid on strength and stability of metal cylindrical silos with corrugated walls (without stiffeners) during filling. The ...behaviour of two bulk solids (dry sand and wheat) was described with a hypoplastic constitutive model. Non-linear FE analyses with both geometric and material non-linearity were performed. The numerical results were compared with the Eurocode formulae. The strengthening effect of the stored solid, wall thickness, solid granular hardness, initial void ratio of solid and wall friction angle on buckling strength was investigated. The major contribution of the paper is the quantitative estimation of the effect of the bulk solid stiffness on the silo stability and wall stresses.
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•We conducted buckling FE analyses for silos with corrugated sheets.•Bulk solid was described with a hypoplastic constitutive model.•Non-linear analyses with geometric and material non-linearity were performed.•The FE results were compared with the Eurocode formulae.
The properties of liquid‐crystalline (LC) hybrid systems made of inorganic nanoparticles grafted with photosensitive azo compounds are presented. For materials with a large density of azo ligands at ...the surface, the LC structure can be reversibly melted by UV light, and the return to the LC state does not require the absorption of visible light. For systems with a lower density of azo ligands, UV light causes shortening of the distance between metal sublayers in the lamellar phase. Interestingly, the azo derivatives attached to the nanoparticle surface show very different kinetics of cis/trans conformational change as compared to the free molecules. The cis form of free ligands in solution is stable for days, whereas the isomerization of molecules attached to the nanoparticle surface to the trans form takes only a few minutes. Apparently, owing to the crowded environment, azo ligands immobilized at a metal surface behave as they would in the condensed state.
Attention!…︁ At ease…︁ Liquid‐crystalline (LC) hybrid systems composed of inorganic nanoparticles grafted with photosensitive azo compounds showed reversible melting into an isotropic liquid under UV illumination (see picture). The resulting change in the interparticle distance may enable the design of LC plasmonic materials with light‐controlled optical properties.
We present a novel approach for the search of dark matter in the DarkSide-50 experiment, relying on Bayesian Networks. This method incorporates the detector response model into the likelihood ...function, explicitly maintaining the connection with the quantity of interest. No assumptions about the linearity of the problem or the shape of the probability distribution functions are required, and there is no need to morph signal and background spectra as a function of nuisance parameters. By expressing the problem in terms of Bayesian Networks, we have developed an inference algorithm based on a Markov Chain Monte Carlo to calculate the posterior probability. A clever description of the detector response model in terms of parametric matrices allows us to study the impact of systematic variations of any parameter on the final results. Our approach not only provides the desired information on the parameter of interest, but also potential constraints on the response model. Our results are consistent with recent published analyses and further refine the parameters of the detector response model.
The electroencephalographic activity of particular brain areas during the decision making process is still little known. This paper presents results of experiments on the group of 30 patients with a ...wide range of psychiatric disorders and 41 members of the control group. All subjects were performing the Iowa Gambling Task that is often used for decision process investigations. The electroencephalographical activity of participants was recorded using the dense array amplifier. The most frequently active Brodmann Areas were estimated by means of the photogrammetry techniques and source localization algorithms. The analysis was conducted in the full frequency as well as in alpha, beta, gamma, delta, and theta bands. Next the mean electric charge flowing through each of the most frequently active areas and for each frequency band was calculated. The comparison of the results obtained for the subjects and the control groups is presented. The difference in activity of the selected Brodmann Areas can be observed in all variants of the task. The hyperactivity of amygdala is found in both the patients and the control group. It is noted that the somatosensory association cortex, dorsolateral prefrontal cortex, and primary visual cortex play an important role in the decision-making process as well. Some of our results confirm the previous findings in the fMRI experiments. In addition, the results of the electroencephalographic analysis in the broadband as well as in specific frequency bands were used as inputs to several machine learning classifiers built in Azure Machine Learning environment. Comparison of classifiers' efficiency is presented to some extent and finding the most effective classifier may be important for planning research strategy toward finding decision-making biomarkers in cortical activity for both healthy people and those suffering from psychiatric disorders.
Brain fog is a kind of mental problem, similar to chronic fatigue syndrome, and appears about 3 months after the infection with COVID-19 and lasts up to 9 months. The maximum magnitude of the third ...wave of COVID-19 in Poland was in April 2021. The research referred here aimed at carrying out the investigation comprising the electrophysiological analysis of the patients who suffered from COVID-19 and had symptoms of brain fog (sub-cohort A), suffered from COVID-19 and did not have symptoms of brain fog (sub-cohort B), and the control group that had no COVID-19 and no symptoms (sub-cohort C). The aim of this article was to examine whether there are differences in the brain cortical activity of these three sub-cohorts and, if possible differentiate and classify them using the machine-learning tools. he dense array electroencephalographic amplifier with 256 electrodes was used for recordings. The event-related potentials were chosen as we expected to find the differences in the patients' responses to three different mental tasks arranged in the experiments commonly known in experimental psychology: face recognition, digit span, and task switching. These potentials were plotted for all three patients' sub-cohorts and all three experiments. The cross-correlation method was used to find differences, and, in fact, such differences manifested themselves in the shape of event-related potentials on the cognitive electrodes. The discussion of such differences will be presented; however, an explanation of such differences would require the recruitment of a much larger cohort. In the classification problem, the avalanche analysis for feature extractions from the resting state signal and linear discriminant analysis for classification were used. The differences between sub-cohorts in such signals were expected to be found. Machine-learning tools were used, as finding the differences with eyes seemed impossible. Indeed, the A&B vs. C, B&C vs. A, A vs. B, A vs. C, and B vs. C classification tasks were performed, and the efficiency of around 60-70% was achieved. In future, probably there will be pandemics again due to the imbalance in the natural environment, resulting in the decreasing number of species, temperature increase, and climate change-generated migrations. The research can help to predict brain fog after the COVID-19 recovery and prepare the patients for better convalescence. Shortening the time of brain fog recovery will be beneficial not only for the patients but also for social conditions.
The paper describes results of experimental investigations of confined granular flow in a silo with different inserts. Over 100 experiments were carried out with dry cohesionless sand in a large ...metal silo with and without inserts at Tel-Tek, dept. POSTEC, in Norway. Wall pressures and flow patterns were measured during both silo filling and emptying. Three different insert types were used in the silo: double cone, cone-in-cone and inverted cone. Different positions of inserts were also investigated. Experimental results with inserts were compared with those without inserts. Some design recommendations for silos equipped with inserts were worked out.
The results of experimental investigations on confined granular flow in a large silo with different inserts (double cone, cone-in-cone and inverted cone) are given. In addition, some design recommendations for silos equipped with inserts are listed. Display omitted
► We perform experimental investigations on sand flow in a full-size silo. ► We use 3 different silo inserts. ► We measure wall pressures and flow patterns during silo filling and emptying. ► We compare experimental results with inserts with those without inserts. ► We work out recommendations for the insert design.
The transmembrane recognition complex (TRC40) pathway mediates the insertion of tail‐anchored (TA) proteins into membranes. Here, we demonstrate that otoferlin, a TA protein essential for hair cell ...exocytosis, is inserted into the endoplasmic reticulum (ER) via the TRC40 pathway. We mutated the TRC40 receptor tryptophan‐rich basic protein (Wrb) in hair cells of zebrafish and mice and studied the impact of defective TA protein insertion. Wrb disruption reduced otoferlin levels in hair cells and impaired hearing, which could be restored in zebrafish by transgenic Wrb rescue and otoferlin overexpression. Wrb‐deficient mouse inner hair cells (IHCs) displayed normal numbers of afferent synapses, Ca2+ channels, and membrane‐proximal vesicles, but contained fewer ribbon‐associated vesicles. Patch‐clamp of IHCs revealed impaired synaptic vesicle replenishment. In vivo recordings from postsynaptic spiral ganglion neurons showed a use‐dependent reduction in sound‐evoked spiking, corroborating the notion of impaired IHC vesicle replenishment. A human mutation affecting the transmembrane domain of otoferlin impaired its ER targeting and caused an auditory synaptopathy. We conclude that the TRC40 pathway is critical for hearing and propose that otoferlin is an essential substrate of this pathway in hair cells.
Synopsis
Otoferlin, a tail‐anchored protein of sensory hair cells, uses the transmembrane recognition complex (TRC40) pathway for ER membrane insertion. Disruption of the TRC40 receptor Wrb in hair cells impaired vesicle replenishment and hearing, most likely by reducing otoferlin levels.
Hearing requires membrane insertion of tail‐anchored (TA) proteins by the TRC40 pathway in hair cells.
The TA protein otoferlin, essential for hair cell exocytosis and defective in human deafness, utilizes the TRC40 pathway.
Deletion of TRC40 receptor WRB reduces otoferlin levels and impairs synaptic structure and function.
Reduced vesicle replenishment in WRB‐deficient hair cells impairs sound encoding.
ER membrane insertion of the sensory hair cell component otoferlin depends on the tail‐anchored protein insertion TRC40 pathway, whose disruption impairs synaptic vesicle replenishment and hearing.
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