Fabrication of Superhydrophilic Polyester Fabrics Using Various TiO₂ Colloidal Dispersions

The purpose of this research was to apply four stable colloidal dispersions, combining different TiO₂ core-shell nanoparticles, onto polyester fabric, according to exhaustion procedure, in order to enhance fabrics' water and moisture absorption properties. Firstly, all colloidal dispersions were analysed using transmission electron microscopy (TEM) and dynamic light scattering (DLS) and secondly, the morphologies of TiO₂ modified PES surfaces were evaluated by scanning electron microscopy (SEM). In addition, the superhydrophilic character of fibrous surfaces was investigated by water contact angle measurement. For this purpose, dynamic tensiometry was employed by measuring the changes in the net force on a surface during the repeated immersion and emersion of a solid into a probe liquid. The obtained results show excellent wettability of TiO₂ upgraded PES fabrics depending on the type of applied nano-sized TiO₂-hybride

The Role of TiO₂ Nanoparticles on the UV Protection Ability and Hydrophilicity of Polyamide Fabrics

The focus of this study was to characterize three industrially-prepared (via the sulphate synthesis process) nano-TiO₂ colloidal dispersions with the intention to elucidate their role on the hydrophilicity as well as UV shielding ability when applied onto polyamide fabric. Transmission electron microscopy (TEM) and UV spectrophotometry of the selected dispersions proved the presence of TiO₂ nanoparticles of different shapes and sizes, as well as its imposing absorption capability within the UV region. In addition, TiO₂ dispersions in three concentrations accompanied by selected chemicals and auxiliaries were applied on polyamide fabrics according to standard exhaustion procedure. Scanning electron microscopy (SEM) was adopted in order to analyse the morphological structure of nano-TiO₂-upgraded PA fabrics. Furthermore, the UV-protective ability and hydrophilic properties were evaluated. The gained results show excellent blocking properties against UV-rays (UPF 50+), as well as the (super)hydrophilicity of TiO₂-modified PA fabrics, regarding the type of employed TiO₂ colloidal dispersion

Elective, Non-urgent Procedures and Aesthetic Surgery in the Wake of SARS-COVID-19: Considerations Regarding Safety, Feasibility and Impact on Clinical Management

BACKGROUND The worldwide spread of a novel coronavirus disease (COVID-19) has led to a near total stop of non-urgent, elective surgeries across all specialties in most affected countries. In the field of aesthetic surgery, the self-imposed moratorium for all aesthetic surgery procedures recommended by most international scientific societies has been adopted by many surgeons worldwide and resulted in a huge socioeconomic impact for most private practices and clinics. An important question still unanswered in most countries is when and how should elective/aesthetic procedures be scheduled again and what kind of organizational changes are necessary to protect patients and healthcare workers when clinics and practices reopen. Defining manageable, evidence-based protocols for testing, surgical/procedural risk mitigation and clinical flow management/contamination management will be paramount for the safety of non-urgent surgical procedures. METHODS We conducted a MEDLINE/PubMed research for all available publications on COVID-19 and surgery and COVID-19 and anesthesia. Articles and referenced literature describing possible procedural impact factors leading to exacerbation of the clinical evolution of COVID-19-positive patients were identified to perform risk stratification for elective surgery. Based on these impact factors, considerations for patient selection, choice of procedural complexity, duration of procedure, type of anesthesia, etc., are discussed in this article and translated into algorithms for surgical/anesthesia risk management and clinical management. Current recommendations and published protocols on contamination control, avoidance of cross-contamination and procedural patient flow are reviewed. A COVID-19 testing guideline protocol for patients planning to undergo elective aesthetic surgery is presented and recommendations are made regarding adaptation of current patient information/informed consent forms and patient health questionnaires. CONCLUSION The COVID-19 crisis has led to unprecedented challenges in the acute management of the crisis, and the wave only recently seems to flatten out in some countries. The adaptation of surgical and procedural steps for a risk-minimizing management of potential COVID-19-positive patients seeking to undergo elective aesthetic procedures in the wake of that wave will present the next big challenge for the aesthetic surgery community. We propose a clinical algorithm to enhance patient safety in elective surgery in the context of COVID-19 and to minimize cross-contamination between healthcare workers and patients. New evidence-based guidelines regarding surgical risk stratification, testing, and clinical flow management/contamination management are proposed. We believe that only the continuous development and broad implementation of guidelines like the ones proposed in this paper will allow an early reintegration of all aesthetic procedures into the scope of surgical care currently performed and to prepare the elective surgical specialties better for a possible second wave of the pandemic. LEVEL OF EVIDENCE V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266

Influence of temperature management on neurocognitive function in biological aortic valve replacement. A prospective randomized trial

Aim of this study was to elucidate if postoperative neurocognitive function after biological aortic valve replacement (AVR) can be influenced by temperature management during cardiopulmonary bypass (CPB)

Characterization of deactivated and regenerated zeolite ZSM-5-based catalyst extrudates used in catalytic pyrolysis of biomass

A major issue in the catalytic fast pyrolysis (CFP) of biomass is the rapid deactivation of the typically employed zeolite-based catalysts. Detailed understanding of the deactivation pathways and the type and location of coke deposits are essential for the further development of improved or new catalyst materials, including appropriate regeneration protocols. Such deactivation and regeneration studies focus almost invariably on small-scale CFP reactor units employing catalyst materials in powder form. In this study, we report the in-depth characterization of deactivated and regenerated ZrO2-promoted zeolite ZSM-5 catalyst extrudates after ex-situ CFP tests carried out in a bench scale reactor. The findings support that coking is the main reason for catalyst deactivation, i.e. for the observed decreased activity in cracking and deoxygenation. Post-mortem characterization by confocal fluorescence microscopy reveals an egg-shell spatial distribution of the coke deposits within the catalyst extrudates. These deposits are heavily poly-aromatic in nature. The majority of the coke build-up occurs in the first 20 min of the reaction and is formed on the strong Brønsted acid sites, which promote deep deoxygenation and cracking. With increasing time-on-stream, the coke deposition slows down, occurring now mainly on the external surface of the zeolite to generate a softer, i.e. more hydrogen-rich, coke on the ZrO2 domains. The catalyst is readily regenerated via thermal oxidation in air, with optimal regeneration at 500 °C. This temperature removes all coke deposits, with no detrimental effect on the catalyst's structural, textural and acid (type and strength) properties