BACKGROUND: Paravalvular leakage (PVL) and conduction disorders that require permanent pacemaker implantation (PPI) remain clinically relevant challenges after transcatheter aortic valve implantation (TAVI). Computed tomography-based simulations may predict the risk of significant PVL and PPI.
OBJECTIVE: To evaluate the feasibility and accuracy of preprocedural computer simulation with FEops HEARTguide™ to predict >trace PVL and PPI after TAVI with the self-expanding supra-annular ACURATE Neo2 transcatheter heart valve.
METHODS: Prospective multicenter observational study that included consecutive patients undergoing TAVI with an ACURATE Neo2 valve. Computer simulations were performed before the TAVI procedure as part of the preprocedural planning. Follow-up period for PPI and PVL was 30 days.
RESULTS: Sixty-five patients were included (median age 81 years (25th-75th percentile 77-84.5)). New left bundle branch block occurred in five patients (7.7%) and PPI in two patients (3%). Contact pressure index (CPI) was similar for patients with vs without new conduction disorders. Patients with PPI had numerically higher CPI than those without PPI (median CPI 20.0% (25th-75th percentile 15.0-25.0) vs. 13.0% (25th-75th percentile 5.5-18), p = 0.27). More than trace PVL occurred in 30%. Median PVL was significantly lower in patients with none-trace PVL (3.2 mL/s [25th-75th percentile 2.2-5.0]), compared to mild PVL (5.2 mL/s [25th-75th percentile 3.2-10.3]) and moderate PVL (12.6 mL/s [25th-75th percentile 3.9-21.3])(p = 0.036). A simulated PVL-cutoff of 9.65 mL/s identified patients with >trace PVL (AUC 0.70 (95% CI 0.55-0.85), sensitivity 42%, specificity 95%).
CONCLUSIONS: In our study FEops HEARTguide™ simulations identified patients at risk for >trace PVL with ACURATE Neo2 TAVI but not for PPI.

Disentangling the roles of structural landscape factors and animal movement behaviour can present challenges for practitioners managing landscapes to maintain functional connectivity and achieve conservation goals. We used a landscape genetics approach to combine robust demographic, behavioural and genetic datasets with spatially explicit simulations to evaluate the effects of anthropogenic barriers (dams, culverts) and natural landscape resistance (gradient, elevation) affecting dispersal behaviour, genetic connectivity and genetic structure in a resident population of Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi). Analyses based on 10 years of sampling effort revealed a pattern of restricted dispersal, and population genetics identified discrete population clusters between distal tributaries and the mainstem stream and no structure within the mainstem stream. Demogenetic simulations demonstrated that, for this population, the effects of existing anthropogenic barriers on population structure are redundant with effects of restricted dispersal associated with the underlying environmental resistance. Our approach provides an example of how extensive field sampling combined with landscape genetics can be incorporated into spatially explicit simulation modelling to explore how, together, movement ecology and landscape resistance can be used to inform decisions around restoration and connectivity.

Cells store triacylglycerol (TAG) within lipid droplets (LDs). A dynamic model describing complete LD formation at the endoplasmic reticulum (ER) membrane does not yet exist. A biochemical-biophysical model of LD synthesis is proposed. It describes the time-dependent accumulation of TAG in the ER membrane as the formation of a potential LD (pLD) bounded by spherical caps of the inner and outer monolayers of the membrane. The expansion rate of the pLD depends on the TAG supply, the elastic properties of the ER membrane, and the recruitment of phospholipids (PLs) to the cap-covering monolayers. Model simulations provided the following insights: (a) Marginal differences in the surface tension of the cap monolayers are sufficient to fully drive the expansion of the pLD towards the cytosol or lumen. (b) Selective reduction of PL supply to the luminal monolayer ensures stable formation of cytosolic LDs, irrespective of variations in the elasto-mechanical properties of the ER membrane. (c) The rate of TAG supply to the cytosolic monolayer has a major effect on the size and maturation time of LDs but has no significant effect on the TAG export per individual LD. The recruitment of additional PLs to the cap monolayers of pLDs critically controls the budding direction, size, and maturation time of LDs. The ability of cells to acquire additional LD initiation sites appears to be key to coping with acutely high levels of potentially toxic free fatty acids.

By means of molecular dynamics computer simulation, the conformational space of polyampholyte macromolecules with various distributions of the charged groups along the chain is studied. A coarse-grained model where each monomer unit of the chain is presented as a non-charged group in the backbone of the macromolecule connected with a charged side pendant is considered. A limiting case of fully charged chains in the isoelectric point is investigated. The oppositely charged monomer units are distributed in various patterns: regular alternating, multiblock, or random sequences. It is found that the chains with random unit distribution adopt much more compacted conformations than the chains with regular distributions with comparable block lengths. Calculating the chain size and its fluctuation along with the spatial density distribution, coil, and globular conformations are distinguished and arranged on the diagrams in terms of chain length, block length, and Bjerrum length.

UNASSIGNED: Clinical and experimental data on the cardiac effects of acute hypernatremia are scarce and inconsistent. We aimed to determine and understand the effects of different levels of acute hypernatremia on the human ventricular action potential.
UNASSIGNED: We performed computer simulations using two different, very comprehensive models of the electrical activity of a single human ventricular cardiomyocyte, i.e., the Tomek-Rodriguez model following the O\'Hara-Rudy dynamic (ORd) model and the Bartolucci-Passini-Severi model as published in 2020 (known as the ToR-ORd and BPS2020 models, respectively). Mild to extreme levels of hypernatremia were introduced into each model based on experimental data on the effects of hypernatremia on cell volume and individual ion currents.
UNASSIGNED: In both models, we observed an increase in the intracellular sodium and potassium concentrations, an increase in the peak amplitude of the intracellular calcium concentration, a hyperpolarization of the resting membrane potential, a prolongation of the action potential, an increase in the maximum upstroke velocity, and an increase in the threshold stimulus current at all levels of hypernatremia and all stimulus rates tested. The magnitude of all of these effects was relatively small in the case of mild to severe hypernatremia but substantial in the case of extreme hypernatremia. The effects on the action potential were related to an increase in the sodium-potassium pump current, an increase in the sodium-calcium exchange current, a decrease in the rapid and slow delayed rectifier potassium currents, and an increase in the fast and late sodium currents.
UNASSIGNED: The effects of mild to severe hypernatremia on the electrical activity of human ventricular cardiomyocytes are relatively small. In the case of extreme hypernatremia, the effects are more pronounced, especially regarding the increase in threshold stimulus current.

Adsorption of surfactants to fluid interfaces occurs in numerous technological and daily-life contexts. The coverage at the interface and other properties of the formed adsorption layers determine the performance of a surfactant with regard to the desired application. Given the importance of these applications, there is a great demand for the comprehensive characterization and understanding of surfactant adsorption layers. In this review, we provide an overview of suitable experimental and simulation-based techniques and review the literature in which they were used for the investigation of surfactant adsorption layers. We come to the conclusion that, while these techniques have been successfully applied to investigate Langmuir monolayers of water-insoluble surfactants, their application to the study of Gibbs adsorption layers of water-soluble surfactants has not been fully exploited. Finally, we emphasize the great potential of these methods in providing a deeper understanding of the behavior of soluble surfactants at interfaces, which is crucial for optimizing their performance in various applications.

UNASSIGNED: The aim of this study was to assess the completeness and readability of generative pre-trained transformer-4 (GPT-4)-generated discharge instructions at prespecified reading levels for common pediatric emergency room complaints.
UNASSIGNED: The outputs for 6 discharge scenarios stratified by reading level (fifth or eighth grade) and language (English, Spanish) were generated fivefold using GPT-4. Specifically, 120 discharge instructions were produced and analyzed (6 scenarios: 60 in English, 60 in Spanish; 60 at a fifth-grade reading level, 60 at an eighth-grade reading level) and compared for completeness and readability (between language, between reading level, and stratified by group and reading level). Completeness was defined as the proportion of literature-derived key points included in discharge instructions. Readability was quantified using Flesch-Kincaid (English) and Fernandez-Huerta (Spanish) readability scores.
UNASSIGNED: English-language GPT-generated discharge instructions contained a significantly higher proportion of must-include discharge instructions than those in Spanish (English: mean (standard error of the mean) = 62% (3%), Spanish: 53% (3%), P = .02). In the fifth-grade and eighth-grade level conditions, there was no significant difference between English and Spanish outputs in completeness. Readability did not differ across languages.
UNASSIGNED: GPT-4 produced readable discharge instructions in English and Spanish while modulating document reading level. Discharge instructions in English tended to have higher completeness than those in Spanish.
UNASSIGNED: Future research in prompt engineering and GPT-4 performance, both generally and in multiple languages, is needed to reduce potential for health disparities by language and reading level.

This study investigates how varying cell size affects the mechanical behaviour of photopolymer Triply Periodic Minimal Surfaces (TPMS) under different deformation rates. Diamond, Gyroid, and Primitive TPMS structures with spatially graded cell sizes were tested. Quasi-static experiments measured boundary forces, representing material behaviour, inertia, and deformation mechanisms. Separate studies explored the base material\'s behaviour and its response to strain rate, revealing a strength increase with rising strain rate. Ten compression tests identified a critical strain rate of 0.7 s-1 for \"Grey Pro\" material, indicating a shift in failure susceptibility. X-ray tomography, camera recording, and image correlation techniques observed cell connectivity and non-uniform deformation in TPMS structures. Regions exceeding the critical rate fractured earlier. In Primitive structures, stiffness differences caused collapse after densification of smaller cells at lower rates. The study found increasing collapse initiation stress, plateau stress, densification strain, and specific energy absorption with higher deformation rates below the critical rate for all TPMS structures. However, cell-size graded Primitive structures showed a significant reduction in plateau and specific energy absorption at a 500 mm/min rate.

This work introduces X-Ray Calc (XRC), an open-source software package designed to simulate X-ray reflectivity (XRR) and address the inverse problem of reconstructing film structures on the basis of measured XRR curves. XRC features a user-friendly graphical interface that facilitates interactive simulation and reconstruction. The software employs a recursive approach based on the Fresnel equations to calculate XRR and incorporates specialized tools for modeling periodic multilayer structures. This article presents the latest version of the X-Ray Calc software (XRC3), with notable improvements. These enhancements encompass an automatic fitting capability for XRR curves utilizing a modified flight particle swarm optimization algorithm. A novel cost function was also developed specifically for fitting XRR curves of periodic structures. Furthermore, the overall user experience has been enhanced by developing a new single-window interface.

Cyclic dinucleotides (CDNs) are cyclic molecules consisting of two nucleoside monophosphates linked by two phosphodiester bonds, which act as a second messenger and bind to the interferon gene stimulating factor (STING) to activate the downstream signaling pathway and ultimately induce interferon secretion, initiating an anti-infective immune response. Cyclic dinucleotides and their analogs are lead compounds in the immunotherapy of infectious diseases and tumors, as well as immune adjuvants with promising applications. Many agonists of pathogen recognition receptors have been developed as effective adjuvants to optimize vaccine immunogenicity and efficacy. In this work, the binding mechanism of human-derived interferon gene-stimulating protein and its isoforms with cyclic dinucleotides and their analogs was theoretically investigated using computer simulations and combined with experimental results in the hope of providing guidance for the subsequent synthesis of cyclic dinucleotide analogs.