Functional Nanocomposite Films of Poly(Lactic Acid) with Well-Dispersed Chitin Nanocrystals Achieved Using a Dispersing Agent and Liquid-Assisted Extrusion Process

The development of bio-based nanocomposites is of high scientific and industrial interest, since they offer excellent advantages in creating functional materials. However, dispersion and distribution of the nanomaterials inside the polymer matrix is a key challenge to achieve high-performance functional nanocomposites. In this context, for better dispersion, biobased triethyl citrate (TEC) as a dispersing agent in a liquid-assisted extrusion process was used to prepare the nanocomposites of poly (lactic acid) (PLA) and chitin nanocrystals (ChNCs). The aim was to identify the effect of the TEC content on the dispersion of ChNCs in the PLA matrix and the manufacturing of a functional nanocomposite. The nanocomposite film’s optical properties; microstructure; migration of the additive and nanocomposites’ thermal, mechanical and rheological properties, all influenced by the ChNC dispersion, were studied. The microscopy study confirmed that the dispersion of the ChNCs was improved with the increasing TEC content, and the best dispersion was found in the nanocomposite prepared with 15 wt% TEC. Additionally, the nanocomposite with the highest TEC content (15 wt%) resembled the mechanical properties of commonly used polymers like polyethylene and polypropylene. The addition of ChNCs in PLA-TEC15 enhanced the melt viscosity, as well as melt strength, of the polymer and demonstrated antibacterial activity.

The Value of Speech-Language Pathologists in Auditory Rehabilitation for Adults With Cochlear Implants

Background Standards for auditory rehabilitation are currently lacking for adults who receive cochlear implants. Speech recognition outcomes are highly variable, and many adults with cochlear implants present with suboptimal performance. Functional real-life communication abilities are not routinely measured clinically and are not strongly linked to performance on traditional measures of speech recognition. In fact, even individuals with relatively good speech recognition outcomes often present with persistent communication difficulties. In contrast to pediatric cochlear implant users, speech-language pathologists are not routinely involved in the rehabilitation of adults who receive cochlear implants. Purpose The purpose of this article is to describe the value of including a speech-language pathologist in a comprehensive approach to auditory rehabilitation for adults with cochlear implants. Method The theoretical and clinical foundations of incorporating a speech-language pathologist into an adult auditory rehabilitation program are discussed. A description of the skills and potential roles of the speech-language pathologist for providing adult cochlear implant rehabilitation services is presented, along with potential barriers to implementation. Conclusion Person-centered management of postlingually deafened adults with cochlear implants can be augmented by a more complete approach utilizing the skill set of a speech-language pathologist. Supplemental Material https://doi.org/10.23641/asha.14669652

Overview of Silica-Polymer Nanostructures for Waterborne High-Performance Coatings

Combining organic and inorganic components at a nanoscale is an effective way to obtain high performance coating materials with excellent chemical and physical properties. This review focuses on recent approaches to prepare hybrid nanostructured waterborne coating materials combining the mechanical properties and versatility of silica as the inorganic filler, with the flexural properties and ease of processing of the polymer matrix. We cover silica-polymer coupling agents used to link the organic and inorganic components, the formation of hybrid films from these silica-polymer nanostructures, and their different applications. These hybrid nanostructures can be used to prepare high performance functional coatings with different properties from optical transparency, to resistance to temperature, hydrophobicity, anti-corrosion, resistance to scratch, and antimicrobial activity.

Effectiveness of Mobile Health–Based Exercise Interventions for Patients with Peripheral Artery Disease: Systematic Review and Meta-Analysis

Background Peripheral artery disease (PAD) affects over 236 million people worldwide, and exercise interventions are commonly used to alleviate symptoms of this condition. However, no previous systematic review has evaluated the effects of mobile health (mHealth)–based exercise interventions for patients with PAD. Objective This study aimed to assess the effect of mHealth-based exercise interventions on walking performance, functional status, and quality of life in patients with PAD. Methods A systematic review and meta-analysis were conducted. We searched in seven databases to identify randomized controlled trials of patients with PAD published in English up to December 4, 2020. Studies were included if patients participated in mHealth-based exercise interventions and were assessed for walking performance. We analyzed pooled effect size on walking performance, functional status, and quality of life based on the standardized mean differences between groups. Results A total of seven studies were selected for the systematic review, and six studies were included in the meta-analysis. The duration of interventions in the included studies was 12 to 48 weeks. In the pooled analysis, when compared with the control groups, the mHealth-based exercise intervention groups were associated with significant improvements in pain-free walking (95% CI 0.13-0.88), maximal walking (95% CI 0.03-0.87), 6-minute walk test (6MWT) distance (95% CI 0.59-1.24), and walking distance (95% CI 0.02-0.49). However, benefits of the interventions on walking speed, stair-climbing ability, and quality of life were not observed. Conclusions mHealth-based exercise interventions for patients with PAD were beneficial for improving pain-free walking, maximal walking, and 6MWT distance. We found that exercise interventions using mHealth are an important strategy for improving the exercise effectiveness and adherence rate of patients with PAD. Future studies should consider the use of various and suitable functions of mHealth that can increase the adherence rates and improve the effectiveness of exercise.

Effectiveness of a task-oriented training on occupational performance, functional independence, and fatigue in children with childhood cancer: a randomized-controlled trial

Objective The objective of the study is to explore the effectiveness of task-oriented training (TOT) on occupational performance, functional independence, and fatigue of children with cancer. Method Two hundred and thirteen children (101 females, 112 males) with cancer were randomized to experimental (n = 112; 9.53±2.23 years) or control (n = 101; 7.93±1.98 years) groups. The experimental group received a TOT together with a conventional occupational therapy (COT), while the control group received only a COT. Both groups received 20 sessions of therapy. The outcomes regarding occupational performance via the Canadian Occupational Performance Measure, functional independence via the Functional Independence Measure for Children and fatigue via the Visual Analog Scale were evaluated by the blind evaluators before and after the interventions in the hospital setting. Results The occupational performance and satisfaction (p<0.001) scores showed statistically significant differences in the experimental group compared to the control group (p<0.01). A statistically significant improvement was determined in functional independence for both groups (p< 0.001). The experimental group indicated a significant reduction in fatigue (p values for fatigue before, during, after activity, morning and evening: p< 0.001) and in the control group (P values for fatigue all situation: p< 0.05). Conclusion The TOT seems to ensure more beneficial effects in increasing occupational performance, improving functional independence in daily activities, and decreasing fatigue at the early phases of inpatient treatment of childhood cancer.

On quasi-singular controls in discrete systems with delay

Сconsider an optimal control problem described by a system of differential controls with a delaying argument and a multipoint performance functional under the assumption that the control domain is convex. A number of integral and multipoint necessary optimality conditions in the case of degeneration of the linearized maximum condition are established.

Engineering at the Nanoscale: A Strategy for Developing High-Performance Functional Polymer Nanocomposites

The talk will concentrate on various approaches being used to engineer materials at the nanoscale for various applications in future technologies. In particular, the case of clay, carbon nanostructures (e.g., nanotubes, graphene), metal oxides, bionanomaterials (cellulose, starch, and chitin) will be used to highlight the challenges and progress. Several bio-degradable polymer systems will be considered, such as rubbers, thermoplastics, thermosets, and their blends for the fabrication of functional polymer nanocomposites. The interfacial activity of nanomaterials in compatibilism binary polymer blends will also be discussed. Various self-assembled architectures of hybrid nanostructures can be made using relatively simple processes. Some of these structures offer an excellent opportunity to probe novel nanoscale behavior and can impart unusual macroscopic end properties. I will talk about various applications of these materials, taking into account their multifunctional properties. Some of the promising applications of clay, metal oxides, nano cellulose, chitin, carbon nanomaterials, and their hybrids will be reviewed.

Hybrid Spider Silk with Inorganic Nanomaterials

High-performance functional biomaterials are becoming increasingly requested. Numerous natural and artificial polymers have already demonstrated their ability to serve as a basis for bio-composites. Spider silk offers a unique combination of desirable aspects such as biocompatibility, extraordinary mechanical properties, and tunable biodegradability, which are superior to those of most natural and engineered materials. Modifying spider silk with various inorganic nanomaterials with specific properties has led to the development of the hybrid materials with improved functionality. The purpose of using these inorganic nanomaterials is primarily due to their chemical nature, enhanced by large surface areas and quantum size phenomena. Functional properties of nanoparticles can be implemented to macro-scale components to produce silk-based hybrid materials, while spider silk fibers can serve as a matrix to combine the benefits of the functional components. Therefore, it is not surprising that hybrid materials based on spider silk and inorganic nanomaterials are considered extremely promising for potentially attractive applications in various fields, from optics and photonics to tissue regeneration. This review summarizes and discusses evidence of the use of various kinds of inorganic compounds in spider silk modification intended for a multitude of applications. It also provides an insight into approaches for obtaining hybrid silk-based materials via 3D printing.