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We investigate the growth of crystals in Zr50Ti50 melts by classical molecular-dynamics simulations with an embedded atom method and a Stillinger–Weber potential model. Both models display fast solidification rates that can be captured by the transition state theory or the Ginzburg–Landau theory at small undercoolings. Fast crystal-growth rates are found to be affected by the pre-existing ordering in liquids, such as the body-centered cubic-like and icosahedral-like structures. The interface-induced ordering unveiled by the crystal-freezing method can explain the rate difference between these two models. However, these orderings fail to rationalize the temperature evolution of the growth rate at deep undercoolings. We correlate the growth kinetics with the detailed dynamical processes in liquids, finding the decoupling of hierarchic relaxation processes when collective motion emerges in supercooled liquids. We find that the growth kinetics is nondiffusive, but with a lower activation barrier corresponding to the structural relaxation or the cage-relative motion in ZrTi melts. These results explore a new relaxation mechanism for the fast growth rate in deeply undercooled liquids. [ABSTRACT FROM AUTHOR]

Previous studies have shown that students learn better from an online lesson when a gesturing pedagogical agent is added (Mayer & DaPra, 2012; Wang, Li, Mayer, & Liu, 2018). The goal of this study is to pinpoint which aspect of a gesturing pedagogical agent causes an improvement in learning from an online lesson. College students learned about neural transmission in an online multimedia lesson that included a pedagogical agent who displayed specific pointing gestures (i.e., pointing to the specific component in the diagram being mentioned in the narration), general pointing gestures (i.e., pointing in the general direction of the diagram), nonpointing gestures (moving hands as beats, moving an arm up or down, or crossing two hands), or no gestures. An analysis of students' eye movements during learning showed that students in the specific-pointing group paid more attention to task-related elements than did students in the other groups (as indicated by fixation time and fixation count on the target area of interest). Students in the specific-pointing group also performed better than the other groups on retention and transfer tests administered immediately after the lesson and after a 1-week delay. The results show that an active ingredient in effective pedagogical agents is the use of specific pointing gestures. This work helps clarify the embodiment principle and image principle by isolating specific pointing (or deictic gestures) as a key feature that makes gesturing effective in multimedia lessons. Educational Impact and Implications Statement: When students learn from multimedia lessons with onscreen pedagogical agents, does the type of gesturing by the agent affect student learning? In this study, students learned better and paid more attention to relevant material on the screen when the onscreen agent used specific pointing gestures during instruction rather than general pointing gestures, nonpointing gestures, or no gestures. Specifically pointing to relevant parts of the onscreen graphic while talking guides the learner's attention and leads to better learning.

The goal of the present study is to determine how to incorporate social cues such as gesturing in animated pedagogical agents (PAs) for online multimedia lessons in ways that promote student learning. In 3 experiments, college students learned about synaptic transmission from a multimedia narrated presentation while their eye movements were tracked and subsequently took learning outcome tests. In Experiments 1 and 2, students who had a gesturing PA added to the screen performed significantly better on learning outcome tests of transfer ("ds" = 0.77 and 0.80) and retention ("ds" = 1.16 and 1.00) and spent more time attending to target material based on eye-tracking measures including fixation time ("ds" = 1.53 and 2.27) and number of fixations ("ds" = 1.54 and 1.70). In Experiments 2 and 3, students who learned with a gesturing PA outperformed those who learned with a static PA on transfer ("ds" = 0.72 and 1.02), retention ("ds" = 0.96 and 0.93), fixation time ("ds" = 2.07 and 1.82), and number of fixations ("ds" = 1.64 and 2.99). In Experiment 2, adding a static PA to the screen did not improve performance. In Experiment 3, adding signaling such as color coding did not improve performance for students who received a gesturing PA. Results support the embodiment principle that people learn better from onscreen multimedia lessons when a gesturing PA is added to the screen, and social agency theory, which posits that social cues can prime learners to process the material more actively and develop better learning outcomes.

Surface induces many fascinating physical phenomena, such as dynamic acceleration, surface anchoring, and orientational wetting, and, thus, is of great interest to study. Here, we report classic molecular dynamics simulations on the free-standing surface of imidazolium-based ionic liquids (ILs) [C4mim][PF6] and [C10mim][PF6]. On [C10mim][PF6] surface, a significant orientational wetting is observed, with the wetting strength showing a diverging tendency. Depth of the wetting was captured from the density and orientational order profile by a static length, which remarkably increases below the temperature Tstat upon cooling down. The dynamical correlation length that measures the distance of surface-dynamics acceleration into the bulk was characterized via the spatial-dependent mobility. The translational correlation exhibits a similar drastic increment at Tstat, while the rotational correlation drastically increases at a lower temperature Trot. We connect these results to the dynamics in bulk liquids, by finding Tstat and Trot that correspond to the onset temperatures where the liquids become cooperative for translational and rotational relaxation, respectively. This signifies the importance of collective dynamics in the bulk on the orientational wetting and surface dynamics in the ILs. [ABSTRACT FROM AUTHOR]

Bevacizumab plays an important role in the first and second line treatment for metastatic colorectal cancer (CRC). And induction of hypoxia and the tumors response to it plays an important role in determining the efficacy of antiangiogenic therapy while the connection between them remains unclear. Here, we found that lactate accumulated in the tumor environment of CRC and acted as substrates for histone lactylation, and this process was further induced by cellular enhanced glycolysis in hypoxia. We determined that CRC patients resistant to bevacizumab treatment presented with elevated levels of histone lactylation and inhibition of histone lactylation efficiently suppressed CRC tumorigenesis, progression and survival in hypoxia. Histone lactylation promoted the transcription of RUBCNL/Pacer, facilitating autophagosome maturation through interacting with BECN1 (beclin 1) and mediating the recruitment and function of the class III phosphatidylinositol 3-kinase complex, which had a crucial role in hypoxic cancer cells proliferation and survival. Moreover, combining inhibition of histone lactylation and macroautophagy/autophagy with bevacizumab treatment demonstrated remarkable treatment efficacy in bevacizumab-resistance patients-derived pre-clinical models. These findings delivered a new exploration and important supplement of metabolic reprogramming-epigenetic regulation, and provided a new strategy for improving clinical efficacy of bevacizumab in CRC by inhibition of histone lactylation. Abbreviations: 2-DG: 2-deoxy-D-glucose; BECN1: beclin 1; CQ: chloroquine; CRC: colorectal cancer; DMOG: dimethyloxalylglycine; H3K18la: histone H3 lysine 18 lactylation; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; Nala: sodium lactate; PDO: patient-derived orgnoid; PDX: patient-derived xenograft; RUBCNL/Pacer: rubicon like autophagy enhancer; SQSTM1/p62: sequestosome 1. [ABSTRACT FROM AUTHOR]