Fabrication of Antibacterial and Antioxidant ZnO-Impregnated Amine-Functionalized Chitosan Bio-Nanocomposite Membrane for Advanced Biomedical Applications.

Developing a variety of safe and effective functioning wound dressings is a never-ending objective. Due to their exceptional antibacterial activity, biocompatibility, biodegradability, and healing-promoting properties, functionalized chitosan nanocomposites have attracted considerable attention in wound dressing applications. Herein, a novel bio-nanocomposite membrane with a variety of bio-characteristics was created through the incorporation of zinc oxide nanoparticles (ZnONPs) into amine-functionalized chitosan membrane (Am-CS). The developed ZnO@Am-CS bio-nanocomposite membrane was characterized by various analysis tools. Compared to pristine Am-CS, the developed ZnO@Am-CS membrane revealed higher water uptake and adequate mechanical properties. Moreover, increasing the ZnONP content from 0.025 to 0.1% had a positive impact on antibacterial activity against Gram-positive and Gram-negative bacteria. A maximum inhibition of 89.4% was recorded against Escherichia coli, with a maximum inhibition zone of 38 ± 0.17 mm, and was achieved by the ZnO (0.1%)@Am-CS membrane compared to 72.5% and 28 ± 0.23 mm achieved by the native Am-CS membrane. Furthermore, the bio-nanocomposite membrane demonstrated acceptable antioxidant activity, with a maximum radical scavenging value of 46%. In addition, the bio-nanocomposite membrane showed better biocompatibility and reliable biodegradability, while the cytotoxicity assessment emphasized its safety towards normal cells, with the cell viability reaching 95.7%, suggesting its potential use for advanced wound dressing applications.

ZnO@ activated carbon derived from wood sawdust as adsorbent for removal of methyl red and methyl orange from aqueous solutions.

Activated carbon (AC) and ZnO@AC composite derived from wood sawdust were prepared to be utilized as adsorbents for methyl red (MR) and methyl orange (MO) anionic dyes from the aqueous solutions. The maximum adsorption capacity of the AC and ZnO@AC composite toward both dyes was achieved in the strong acidic medium (pH = 3), and under stirring for 60 min. The kinetic studies revealed that the adsorption of MR and MO dyes onto the AC and ZnO@AC composite fitted well with the pseudo-second-order model. Furthermore, the intraparticle diffusion and Elovich kinetic models confirmed the adsorption is controlled by external surfaces, and the adsorption is chemisorption process. The isotherm results indicated that the MR and MO dye adsorption occurred via monolayer adsorption, and the estimated maximum adsorption capacities of both dyes onto the ZnO@AC composite were higher than those achieved by AC. Thermodynamic analysis suggested that the adsorption is endothermic and spontaneous. The mechanism for MR, and MO dyes adsorption onto the AC and ZnO@AC composite is proposed to be controlled by electrostatic bonding, π-π interactions, and ion exchange, while H-bonding and n-π interactions were minor contributors. This study reveals the potential use of carbon-based adsorbents derived from wood sawdust for the removal of anionic dyes from wastewater.

Position Statement on In-hospital/Clinic Point-of-care Coagulation Testing for Anticoagulation Monitoring in Saudi Arabia.

Objectives: Hospital overload is a persistent occurrence in daily practice. Interventions such as point-of-care testing (POCT) are needed to alleviate the pressure faced by healthcare providers and administrators. Methods: An invited panel of experts from Saudi Arabia was formed under the auspices of the Saudi Heart Association in order to discuss local treatment gaps in the management of patients receiving anticoagulation therapy. This was done in a series of meetings, which resulted in the development of official recommendations for the implementation of POCT for anticoagulation monitoring in the country. Recommendations were based on a comprehensive literature review and international guidelines taking into consideration local clinical practice, clinical gaps, and treatment/testing availabilities. Results: Vitamin K antagonist (VKA)-based anticoagulation therapy requires routine monitoring. POCT is a promising model of care for the monitoring of International Normalized Ratio (INR) in patients receiving oral anticoagulation in terms efficacy, safety and convenience. The availability of POC INR testing should not replace the use of standard laboratory anticoagulation monitoring. However, there are several indications for implementing POCTINR monitoring that was agreed upon by the expert panel. POCT for anticoagulation monitoring should primarily be used in the warfarin (or other VKA) monitoring clinic in order to ensure treatment efficiency, cost-effectiveness of care, patient satisfaction, and quality of life improvement. The expert panel detailed the requirements for the establishment of a warfarin (or other VKA) monitoring clinic in terms of organization, safety, quality control, and other logistic and technical considerations. The limitations of POCT should be recognized and recommendations on best practices should be strictly followed. Core laboratory confirmation should be sought for patients with higher INR results (>4.7) on POCT. Proper training, quality control, and regulatory oversight are also critical for preserving the accuracy and reliability of POCT results. Conclusions: POCT enables more rapid clinical decision-making in the process of diagnosis (rule-in or rule-out), treatment choice and monitoring, and prognosis, as well as operational decision-making and resource utilization. POCT thus can fulfill an important role in clinical practice, particularly for patients receiving VKAs.

Modified natural kaolin clay as an active, selective, and stable catalyst for methanol dehydration to dimethyl ether.

In this work, the production of dimethyl ether (DME) from methanol over natural kaolin clay modified through impregnation with various percentages of H2SO4, WO3, or ZrO2 catalysts was investigated. The prepared catalysts were characterized via X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and N2-sorption analysis. The acidity of these catalysts was determined through the dehydration of isopropyl alcohol and the chemisorption of pyridine. The catalytic activity performance revealed that the addition of modifiers into kaolin enhanced the latter's activity toward DME production. In addition, the kaolin clay modified with 10 wt% ZrO2 exhibited excellent activity of 98% conversion with 100% selectivity at 275 °C. Moreover, this catalyst could proceed the reaction for a long time (6 days) without any noticeable deactivation. The remarkable improvement in the catalytic performance achievement was well correlated with the acidity and the structure of the catalysts.