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Tumor suppressor protein p53 is regulated in a number of ways, including during initiation of TP53 mRNA translation. The 50 end of TP53 mRNA contains regulatory structures that enable noncanonical initiation using mechanisms that remain poorly described. Here we analyze per-nucleotide reactivity changes in the 50 end secondary structure of TP53 mRNA under in-cell conditions using A549 human lung carcinoma cells. We first construct a cell-free secondary structure model using SHAPE reagent 5-nitroisatoic anhydride on gently extracted and deproteinated RNA. We observe previously described regulatory features of the TP53 mRNA 50 end including two motifs which we refer to as long stem-loop (LSL) and short stem-loop (SSL), respectively. We observe a domain-forming helix that groups LSL and SSL, forming a three-helix junction. Applying in-cell selective 20 hydroxyl acylation analyzed by primer extension and mutational profiling, we assess reactivity profiles with unstressed cells and with chemically induced stress conditions expected to stimulate TP53 cap-independent translation. We analyze the effects of etoposide-induced DNA damage, CoCl2-induced hypoxia, and 50 cap inhibition with 4EGI-1 treatment. Identifying stress-associated changes in the TP53 50 end may help elucidate therole of regulatory RNA structure in cap-independent translation. Using DSHAPE, we identify in-cell protection sites that correspond with previously described RNA–protein binding sites on the apical loops of LSL and SSL. Furthermore, we identify several other potential interaction sites, some associated with specific types of stress. Some noteworthy changes include DeltaSHAPE sites proximal to the start codons, at the three-helix junction and on the domain-forming helix. We summarize potential interactions on the cell-free secondary structure model. 

Background:Peripheral intravenous catheter (PIVC) insertion is an essential skill for nursing professionals. Nursing students face significant challenges in learning PIVC insertion due in part to limited opportunities for hands-on practice with real patients. Traditional training methods with low-fidelity task trainers lack variability and depend on costly consumable products. Purpose:To address this gap, a bimodal haptic feedback interface integrated into mixed reality was developed to simulate IV needle insertion under diverse conditions, creating a simulated learning environment to master tactile skills, hand-eye coordination, and anatomically accurate procedures. Guided by the New Theory of Disuse, the simulator was designed to promote repeated practice and retrieval, strengthening both the accessibility and accuracy of skill performance through targeted, interactive learning. Results:Students reported an improvement in confidence levels and success rate after using the bimanual haptic feedback mixed reality IV simulator. Conclusions:By integrating features such as patient-specific anatomical variability, realistic resistance feedback, and adaptive difficulty levels, virtual reality and haptic simulations can closely replicate the nuances of IV insertion in diverse clinical scenarios. 

Abstract Various metastable ice phases and their complicated transition pathways have been found by pressurization at low temperatures at which slow kinetics and high metastability are easily achieved. By contrast, such diversity is less expected at room or elevated temperatures. Here, using a combination of a dynamic diamond anvil cell and X-ray free electron laser techniques, we demonstrate that supercompressed water transforms into ice VI through multiple freezing–melting pathways at room temperature, hidden within the pressure region of ice VI. These multiple transition pathways occur via a metastable ice (more specifically, ice XXI with body-centred tetragonal structure ($$I\bar{4}2d$$ $I\overline{4}2d$)) discovered in this study and a metastable ice VII that exists within the pressure range of ice VI. We find that supercompressed water structurally evolves from high-density water to very-high-density water, causing multiple transition pathways. These findings provide an insight to find more metastable ice phases and their transition pathways at elevated temperatures. 

The design of organic–peptide hybrids has the potential to combine our vast knowledge of protein design with small molecule engineering to create hybrid structures with complex functions. Here, we describe the computational design of a photoswitchable Ca²⁺-binding organic–peptide hybrid. The designed molecule, designated Ca²⁺-binding switch (CaBS), combines an EF-hand motif from classical Ca²⁺-binding proteins such as calmodulin with a photoswitchable group that can be reversibly isomerized between a spiropyran (SP) and merocyanine (MC) state in response to different wavelengths of light. The MC/SP group acts both as a photoswitch as well as an optical sensor of Ca²⁺binding. Photoconversion of the SP to the corresponding MC unmasks an acidic phenol, which CaBS uses as an integral part of both its Ca²⁺-binding site as well as its tertiary and quaternary structure. By design, the SP state of CaBS is monomeric, while the Ca²⁺-bound form of the MC state is an obligate dimer, with two Ca²⁺-binding sites formed at the interface of a domain-swapped dimer. Thus, light and Ca²⁺were expected to serve as an “AND gate” that powers a change in backbone structure/dynamics, oligomerization state, and fluorescence properties of the designed molecule. CaBS was designed using Rosetta and molecular dynamics simulations, and experimentally characterized by nuclear magnetic resonance, isothermal titration calorimetry, and optical titrations. These data illustrate the potential of combining small molecule engineering with de novo protein design to develop sensors whose conformation, association state, and optical properties respond to multiple environmental cues. 

Like many parents, visually impaired parents (VIPs) read books with their children. However, research on accessible reading technologies predominantly focuses on blind adults reading alone or sighted adults reading with blind children, such that the motivations, strategies, and needs of blind parents reading with their sighted children are still largely undocumented. To address this gap, we interviewed 13 VIPs with young children. We found that VIPs (1) sought familial intimacy through reading with their child, often prioritizing intimacy over their own access needs, (2) took on many types of access labor to read with their children, and (3) desired novel assistive technologies (ATs) for reading that prioritize intimacy while reducing access labor. We contribute the notion of Intimate AT, along with a demonstrative design space, which together constitute a new design paradigm that draws attention to intimacy as a facet of both independently and collaboratively accessible ATs.