Carbon Threads Supercapacitors for Washable e-Textile Applications: Configurations and Electrochemical Performance.

Technological solutions for emerging e-textiles are being sought to enable e-wear technology to be self-sustaining and lightweight. A rippling 1D carbon fiber capacitor design was made with commercial carbon threads as electrodes using simulated sweat solution as the electrolyte. This is particularly relevant for potential sports textile applications in which sweat could serve as an electrochemical energy source. An electrospun cellulose acetate fiber membrane and a commercially available felt were used as separators capable of soaking the electrolyte. These were tested in braided and woven electrode configurations, respectively. Functionalizing the carbon wires with polypyrrole (PPy) enhanced the surface area and significantly increased the specific capacity by approximately an order of magnitude (0.62 F/g). Cyclic voltammetry and charge-discharge tests confirmed the washability and durability of the devices for at least 1000 cycles.

Electrospray Deposition of PEDOT:PSS on Carbon Yarn Electrodes for Solid-State Flexible Supercapacitors.

The increasing demand for flexible electronic devices has risen due to the high interest in electronic textiles (e-textiles). Consequently, the urge to power e-textiles has sparked enormous interest in flexible energy storage devices. One-dimensional (1D) configuration supercapacitors are the most promising technology for textile applications, but often their production involves complex synthesis techniques and expensive materials. This work unveils the use of the novel electrospray deposition (ESD) technique for the deposition of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS). This deposition methodology on conductive carbon yarns creates flexible electrodes with a high surface area. The deposition conditions of PEDOT:PSS were optimized, and their influence on the electrochemical performance of a 1D symmetric supercapacitor with a cellulose-based gel as an electrolyte and a separator was evaluated. The tests herein reported show that these capacitors exhibited a high specific capacitance of 72 mF g-1, an excellent cyclability of more than 85% capacitance retention after 1500 cycles, and an outstanding capability of bending.

Functionalisation of Electrospun Cellulose Acetate Membranes with PEDOT and PPy for Electronic Controlled Drug Release.

Controlled drug release via electrical stimulation from drug-impregnated fibres was studied using electrospun cellulose acetate (CA) membranes and encapsulated ibuprofen (IBU). This research outlines the influence of polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT)-functionalised CA membranes and their suitability for dermal electronic-controlled drug release. Micro Raman analysis confirmed polymer functionalisation of CA membranes and drug incorporation. Scanning electron microscopy (SEM) images evidenced the presence of PPy and PEDOT coatings. The kinetic of drug release was analysed, and the passive and active release was compared. In the proposed systems, the drug release is controlled by very low electrical potentials. A potential of -0.3 V applied to membranes showed the ibuprofen retention, and a positive potential of +0.3 V, +0.5 V, or +0.8 V, depending on the conductive polymer and membrane configuration, enhanced the drug release. A small adhesive patch was constructed to validate this system for cutaneous application and verified an "ON/OFF" ibuprofen release pattern from membranes.

Recent Advances and Challenges Toward Application of Fibers and Textiles in Integrated Photovoltaic Energy Storage Devices.

Flexible microelectronic devices have seen an increasing trend toward development of miniaturized, portable, and integrated devices as wearable electronics which have the requirement for being light weight, small in dimension, and suppleness. Traditional three-dimensional (3D) and two-dimensional (2D) electronics gadgets fail to effectively comply with these necessities owing to their stiffness and large weights. Investigations have come up with a new family of one-dimensional (1D) flexible and fiber-based electronic devices (FBEDs) comprising power storage, energy-scavenging, implantable sensing, and flexible displays gadgets. However, development and manufacturing are still a challenge owing to their small radius, flexibility, low weight, weave ability and integration in textile electronics. This paper will provide a detailed review on the importance of substrates in electronic devices, intrinsic property requirements, fabrication classification and applications in energy harvesting, energy storage and other flexible electronic devices. Fiber- and textile-based electronic devices for bulk/scalable fabrications, encapsulation, and testing are reviewed and presented future research ideas to enhance the commercialization of these fiber-based electronics devices.

Drug Delivery from PCL/Chitosan Multilayer Coatings for Metallic Implants.

Implant-related infections, mainly caused by Staphylococcus aureus, are a major health concern. Treatment is challenging due to multi-resistant strains and the ability of S. aureus to adhere and form biofilms on bone and implant surfaces. The present work involved the preparation and evaluation of a novel dual polymeric film coating on stainless steel. Chitosan and polycaprolactone (PCL) multilayers, loaded with poly(methyl methacrylate) (PMMA) microspheres encapsulating vancomycin or daptomycin, produced by the dip-coating technique, allowed local antibiotic-controlled delivery for the treatment of implant-related infections. Enhanced adhesion of the film to the metal substrate surface was achieved by mechanical abrasion of its surface. Studies have shown that for both drugs the release occurs by diffusion, but the release profile depends on the type of drug (daptomycin or vancomycin), the pH of the solution, and whether the drug is freestanding (directly incorporated into the films) or encapsulated in PMMA microspheres. Daptomycin freestanding films reached 90% release after 1 day at pH 7.4 and 4 days at pH 5.5. In comparison, films with daptomycin encapsulated microspheres reached 90% release after 2 h at pH 5.5 and 2 days at pH 7.4. Vancomycin encapsulated and freestanding films showed a similar behavior reaching 90% release after 20 h of release at pH 5.5 and 2 and 3 days, respectively, at pH 7.4. Furthermore, daptomycin-loaded films showed activity (assessed by agar diffusion assays) against sensitive (ATCC 25923) and clinically isolated (MRSA) S. aureus strains.

Cellulose acetate fibres loaded with daptomycin for metal implant coatings.

Multifunctional polymeric coatings containing drug delivery vehicles can play a key role in preventing/reducing biofilm formation on implant surfaces. Their requirements are biocompatibility, good adhesion, and controllable drug release. Although cellulose acetate (CA) films and membranes are widely studied for scaffolding, their applications as a protective coating and drug delivery vehicle for metal implants are scarce. The reason is that adhesion to stainless steel (SS) substrates is non-trivial. Grinding SS substrates enhances the adhesion of dip-coated CA films while the adhesion of electrospun CA membranes is improved by an electrosprayed chitosan intermediate layer. PMMA microcapsules containing daptomycin have been successfully incorporated into CA films and fibres. The released drug concentration of 3 × 10-3 mg/mL after 120 min was confirmed from the peak luminescence intensity under UV radiation of simulated body fluid (SBF) after immersion of the fibres.

Electronic control of drug release from gauze or cellulose acetate fibres for dermal applications.

Electronic controlled drug release from fibres was studied using ibuprofen as a model drug, one of the most popular analgesics, to impregnate gauze and cellulose acetate (CA) membranes. Conductivity in the range of 1-10 mS cm-1 was obtained in polypyrrole (Ppy) functionalised gauze and CA fibres, providing voltage-controlled drug release in a system consisting of Ppy/Ibuprofen/Ppy membranes and an Ag electrode. SEM images evidenced the Ppy adhesion to fibres and Micro Raman spectra proved drug incorporation and release. A small wound adhesive built with these membranes retains ibuprofen at 1.5 V and quickly releases it when -0.5 V is applied.

Customized tracheal design using 3D printing of a polymer hydrogel: influence of UV laser cross-linking on mechanical properties.

BACKGROUND: The use of 3D printing of hydrogels as a cell support in bio-printing of cartilage, organs and tissue has attracted much research interest. For cartilage applications, hydrogels as soft materials must show some degree of rigidity, which can be achieved by photo- or chemical polymerization. In this work, we combined chemical and UV laser polymeric cross-linkage to control the mechanical properties of 3D printed hydrogel blends. Since there are few studies on UV laser cross-linking combined with 3D printing of hydrogels, the work here reported offered many challenges. METHODS: Polyethylene glycol diacrylate (PEGDA), sodium alginate (SA) and calcium sulphate (CaSO4) polymer paste containing riboflavin (vitamin B2) and triethanolamine (TEOHA) as a biocompatible photoinitiator was printed in an extrusion 3D plotter using a coupled UV laser. The influence of the laser power on the mechanical properties of the printed samples was then examined in unconfined compression stress-strain tests of 1 × 1 × 1 cm3 sized samples. To evaluate the adhesion of the material between printed layers, compression measurements were performed along the parallel and perpendicular directions to the printing lines. RESULTS: At a laser density of 70 mW/cm2, Young's modulus was approximately 6 MPa up to a maximum compression of 20% in the elastic regime for both the parallel and perpendicular measurements. These values were within the range of biological cartilage values. Cytotoxicity tests performed with Vero cells confirmed the cytocompatibility. CONCLUSIONS: We printed a partial tracheal model using optimized printing conditions and proved that the materials and methods developed may be useful for printing of organ models to support surgery or even to produce customized tracheal implants, after further optimization.

Fluency profile: comparison between Brazilian and European Portuguese speakers / Perfil da fluência: comparação entre falantes do Português Brasileiro e do Português Europeu

The purpose of the study was to compare the speech fluency of Brazilian Portuguese speakers with that of European Portuguese speakers. The study participants were 76 individuals of any ethnicity or skin color aged 18-29 years. Of the participants, 38 lived in Brazil and 38 in Portugal. Speech samples from all participants were obtained and analyzed according to the variables of typology and frequency of speech disruptions and speech rate. Descriptive and inferential statistical analyses were performed to assess the association between the fluency profile and linguistic variant variables. We found that the speech rate of European Portuguese speakers was higher than the speech rate of Brazilian Portuguese speakers in words per minute (p=0.004). The qualitative distribution of the typology of common dysfluencies (p<0.001) also discriminated between the linguistic variants. While a speech fluency profile of European Portuguese speakers is not available, speech therapists in Portugal can use the same speech fluency assessment as has been used in Brazil to establish a diagnosis of stuttering, especially in regard to typical and stuttering dysfluencies, with care taken when evaluating the speech rate.

O objetivo do estudo foi comparar a fluência de fala de falantes do Português Brasileiro com a de falantes do Português Europeu. Participaram deste estudo 76 indivíduos, sem distinção de raça e cor, com idades entre 18 e 29 anos, sendo 38 residentes no Brasil e 38 em Portugal. Foram obtidas amostras de fala de todos os participantes e analisadas segundo as variáveis de tipologia e frequência das disfluências e velocidade de fala. Foi realizada análise estatística descritiva e inferencial para verificar a associação entre as variáveis do perfil da fluência e da variante linguística. Foi observado que a velocidade de fala dos falantes do Português Europeu em palavras por minuto (p=0,004) é maior que a dos falantes do Português Brasileiro. A distribuição qualitativa das tipologias das disfluências comuns (p<0,001) também diferencia as variantes linguísticas. Enquanto não há um perfil de fluência de fala dos falantes do Português Europeu, para se estabelecer um diagnóstico de gagueira, os fonoaudiólogos podem utilizar em Portugal a mesma avaliação de fluência de fala utilizada no Brasil, principalmente no que se refere às disfluências comuns e gagas, tendo cuidado apenas no que se refere à velocidade de fala.

Fluency profile: comparison between Brazilian and European Portuguese speakers.

The purpose of the study was to compare the speech fluency of Brazilian Portuguese speakers with that of European Portuguese speakers. The study participants were 76 individuals of any ethnicity or skin color aged 18-29 years. Of the participants, 38 lived in Brazil and 38 in Portugal. Speech samples from all participants were obtained and analyzed according to the variables of typology and frequency of speech disruptions and speech rate. Descriptive and inferential statistical analyses were performed to assess the association between the fluency profile and linguistic variant variables. We found that the speech rate of European Portuguese speakers was higher than the speech rate of Brazilian Portuguese speakers in words per minute (p=0.004). The qualitative distribution of the typology of common dysfluencies (p<0.001) also discriminated between the linguistic variants. While a speech fluency profile of European Portuguese speakers is not available, speech therapists in Portugal can use the same speech fluency assessment as has been used in Brazil to establish a diagnosis of stuttering, especially in regard to typical and stuttering dysfluencies, with care taken when evaluating the speech rate.