Performing conventional mechanical characterization techniques on soft materials can be challenging due to issues such as limited sample volumes and clamping difficulties. Deep indentation and puncture is a promising alternative as it is an information-rich measurement with the potential to be performed in a high-throughput manner. Despite its promise, the method lacks standardized protocols, and open questions remain about its possible limitations.
View Article and Find Full Text PDFImportance: Despite interest in therapy de-escalation for survivors of human papillomavirus-mediated oropharyngeal squamous cell carcinoma (HPV-positive OPSCC), the association of de-escalated therapy with patient-reported quality of life (QoL) outcomes and burden of depressive symptoms remains unclear.
Objective: To identify associations between clinicopathologic and therapeutic variables with patient-reported QoL outcomes and depression symptom burden in patients with HPV-positive OPSCC, who were enrolled in a therapy de-escalation trial.
Design, Setting, And Participants: In this nonrandomized controlled, open-label, curative-intent therapy de-escalation clinical trial in adults with stage I, II, and III HPV-positive OPSCC, patients were recruited from a high-volume head and neck oncology practice.
Bioinspired iron-catechol cross-links have shown remarkable success in increasing the mechanical properties of polymer networks, in part due to clustering of Fe-catechol domains which act as secondary network reinforcing sites. We report a versatile synthetic procedure to prepare modular PEG-acrylate networks with independently tunable covalent bis(acrylate) and supramolecular Fe-catechol cross-linking. Initial control of network structure is achieved through radical polymerization and cross-linking, followed by postpolymerization incorporation of catechol units via quantitative active ester chemistry and subsequent complexation with iron salts.
View Article and Find Full Text PDFThe genome content of adeno-associated virus (AAV) vectors is critical to the safety and potency of AAV-based gene therapy products. Empty capsids are considered a product-related impurity and a critical quality attribute (CQA) of the drug product, thus requiring characterization throughout the production process to demonstrate they are controlled to acceptable levels in the final drug product. Anion exchange chromatography has been used to achieve separation between empty and full capsids, but requires method development and gradient optimization for different serotypes and formulations.
View Article and Find Full Text PDFReconfigurable polymer networks are gaining interest for their potential applications as self-healing, recyclable, and stimuli-responsive smart materials. Relating the bond strength of dynamic interactions to material properties including stress relaxation time and modulus is crucial for smart material design. In this work, crosslinked transition metal-terpyridine reconfigurable networks were utilized to modulate the characteristic network stress relaxation time, .
View Article and Find Full Text PDFMaterials that utilize heterogeneous microstructures to control macroscopic mechanical response are ubiquitous in nature. Yet, translating nature's lessons to create synthetic soft solids has remained challenging. This is largely due to the limited synthetic routes available for creating soft composites, particularly with submicron features, as well as uncertainty surrounding the role of such a microstructured secondary phase in determining material behavior.
View Article and Find Full Text PDFRapid expansion of soft solids subjected to a negative hydrostatic stress can occur through cavitation or fracture. Understanding how these two mechanisms relate to a material's molecular structure is important to applications in materials characterization, adhesive design, and tissue damage. Here, a recently improved needle-induced cavitation (NIC) protocol is applied to a set of model end-linked PEG gels with quantitatively linked elastic and fracture properties.
View Article and Find Full Text PDFAn important but often overlooked feature of Diels-Alder (DA) cycloadditions is the ability for DA adducts to undergo mechanically induced cycloreversion when placed under force. Herein, we demonstrate that the commonly employed DA cycloaddition between furan and maleimide to crosslink hydrogels results in slow gelation kinetics and "mechanolabile" crosslinks that relate to reduced material strength. Through rational computational design, "mechanoresistant" DA adducts were identified by constrained geometries simulate external force models and employed to enhance failure strength of crosslinked hydrogels.
View Article and Find Full Text PDFAdvances in polymer chemistry over the last decade have enabled the synthesis of molecularly precise polymer networks that exhibit homogeneous structure. These precise polymer gels create the opportunity to establish true multiscale, molecular to macroscopic, relationships that define their elastic and failure properties. In this work, a theory of network fracture that accounts for loop defects is developed by drawing on recent advances in network elasticity.
View Article and Find Full Text PDFIntroduction: Intellectual and developmental disabilities (IDD) include conditions associated with physical, learning, language, behavioural, and/or intellectual impairment. Pain is a common and debilitating secondary condition compromising functional abilities and quality of life.
Objectives: This article addresses scientific and clinical challenges in pain assessment and management in individuals with severe IDD.
This parallel group randomized controlled trial tested effectiveness of the Let's Talk About Pain training on respite workers' (RW) pain-related knowledge and feasibility-confidence-skill ratings using between-group and within-group analyses. Fourteen children's respite organizations were randomized to pain or control training. Participants (nintervention = 66; ncontrol = 92) underwent a 3-3.
View Article and Find Full Text PDFWithin a parallel-group randomized control trial, pain training's impact on Respite Workers' (RW) care approaches and training evaluations was explored. RW (n = 158) from 14 organizations received pain or control training following randomization. Researchers were blind until randomization; allocations were not shared explicitly with organizations/participants.
View Article and Find Full Text PDFDeep indentation and puncture can be used to characterize the large strain elastic and fracture properties of soft solids and biological tissues. While this characterization method is growing in application there are still open questions about deep indentation and puncture, including how the distribution of strains and stresses in the surrounding material relate to the resultant force exerted on the indenter. Direct quantification of the deformation field around a rigid indenter during penetration of a soft solid is necessary to substantiate the current qualitative understanding of these strains and increase the impact and usefulness of puncture tests.
View Article and Find Full Text PDFObjective: To characterize musculoskeletal pain intensity, duration, frequency, and interference with activities of daily living in children with cerebral palsy (CP) before and after intrathecal baclofen pump placement.
Design: Prospective cohort study.
Setting: Children's tertiary hospital.
Objectives: Neutrophil-lymphocyte ratio (NLR) has been associated with mortality in non-small cell lung cancer (NSCLC), but its association with recurrence in locally advanced NSCLC (LA-NSCLC), specifically, is less established. We hypothesized pre- and posttreatment NLR would be associated with recurrence and mortality.
Methods: We studied the association of pretreatment NLR (pre-NLR) and posttreatment NLR at 1 (post-NLR) and 3 months (post-NLR) with outcomes in patients with LA-NSCLC treated with chemoradiation.
Characterizing the high-strain-rate and high-strain mechanics of soft materials is critical to understanding the complex behavior of polymers and various dynamic injury mechanisms, including traumatic brain injury. However, their dynamic mechanical deformation under extreme conditions is technically difficult to quantify and often includes irreversible damage. To address such challenges, we investigate an experimental method, which allows quantification of the extreme mechanical properties of soft materials using ultrafast stroboscopic imaging of highly reproducible laser-induced cavitation events.
View Article and Find Full Text PDFIntroduction: Intellectual and developmental disabilities (IDD) include conditions associated with physical, learning, language, behavioural, and/or intellectual impairment. Pain is a common and debilitating secondary condition compromising functional abilities and quality of life.
Objectives: This article addresses scientific and clinical challenges in pain assessment and management in individuals with severe IDD.
Background Immobilization after hip reconstruction in children with cerebral palsy varies according to surgeon preference. The effect of postoperative immobilization on postoperative pain is unknown. Success in achieving hip stability and complications may also differ depending on the immobilization technique utilized.
View Article and Find Full Text PDFObjective: Pain is common for children with intellectual and developmental disabilities. It is critical that caregivers have adequate pain assessment and management knowledge. The program has shown promise to provide pain-related knowledge and skills to respite workers; however, more systematic evaluation of the program is needed.
View Article and Find Full Text PDFElectroadhesion provides a simple route to rapidly and reversibly control adhesion using applied electric potentials, offering promise for a variety of applications including haptics and robotics. Current electroadhesives, however, suffer from key limitations associated with the use of high operating voltages (>kV) and corresponding failure due to dielectric breakdown. Here, a new type of electroadhesion based on heterojunctions between iono-elastomer of opposite polarity is demonstrated, which can be operated at potentials as low as ≈1 V.
View Article and Find Full Text PDFObjective: Pain is common and complex for children with intellectual and developmental disabilities (I/DD). Secondary caregivers such as respite workers are lacking important pain-related information which can impact care. Here, we outline a randomized controlled trial (RCT) protocol testing the effectiveness of a pain training for respite workers supporting children with I/DD.
View Article and Find Full Text PDFCavitation is the sudden, unstable expansion of a void or bubble within a liquid or solid subjected to a negative hydrostatic stress. Cavitation rheology is a field emerging from the development of a suite of materials characterization, damage quantification, and therapeutic techniques that exploit the physical principles of cavitation. Cavitation rheology is inherently complex and broad in scope with wide-ranging applications in the biology, chemistry, materials, and mechanics communities.
View Article and Find Full Text PDFBackground: Immune dysregulation may play a role in the development of Rett syndrome (RTT), a neurodevelopmental disorder caused by mutations of the MECP2 gene. Abnormal cytokine concentrations have been documented in the serum of individuals with RTT. Measurement of salivary cytokines has been investigated as a potential alternative approach to measurement in blood and serum, but it is unclear whether salivary cytokine concentrations can provide valid information about systemic immune function in neurodevelopmental disorders.
View Article and Find Full Text PDFFor patients ineligible for cisplatin with definitive radiotherapy (CP-CRT) for locally advanced head and neck squamous cell carcinoma (LA-HNSCC), concurrent cetuximab (C225-RT) is a popular substitute. Carboplatin-based chemoradiation (CB-CRT) is another option; however, relative efficacies of CP-CRT, CB-CRT and C225-RT are unclear, particularly in the human papillomavirus (HPV)-unrelated population. We identified 316 patients with stage III-IVB cancers of the oropharynx (24.
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