Novel Antibacterial and Bioactive Silicate Glass Nanoparticles for Biomedical Applications

In this work, the authors propose a new quick sol–gel procedure for bioglass nanoparticles production containing 10% mol of silver (AgBGs). These new AgBGs are characterized by Zeta potential analysis, scanning electron microscopy with X‐ray microanalysis (SEM/EDS), X‐ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and microbiological tests to confirm their bioactive and antibacterial properties. SEM shows that the average particle size is less than 200 nm and EDS confirms the successful incorporation of Ag₂O in the bioglass matrix. XRD confirms the amorphous nature of the AgBGs and, after SBF immersion, reveals their bioactive behavior with the presence of crystalline phase of calcium silicate and phosphorus oxide, which are also detected by FTIR analysis. FTIR also confirms the formation of typical siloxane bonds resulting from the condensation of silicate glass. Lastly, it is found that the developed AgBGs has an antibacterial effect against two different types of bacteria, thus demonstrating their ability to reduce the bacterial infection within 16 h.

     

Orbital remote sensing of phytoplankton functional types: a new review

Phytoplankton functional types (PFTs) are groups of species that have specific roles in the biogeochemical cycles and trophic flow. These groups have been pointed out as keys to improve the knowledge on ecosystem dynamics and effects of climate and anthropogenic changes in the marine environment. Orbital remote sensing is stated as the only means capable of analysing spatio-temporal distribution of PFTs, over regional and global scales. Many research teams have focused their efforts on the development of PFT bio-optical models, presenting a great variety of approaches. Considerable advances have been achieved in a few years of research; however, challenges are still great. Further developments rely on improvements in the knowledge of PFTs' bio-optical characteristics and the possibility of integrating different bio-optical and ecological information. This article presents a new review of the state of the art of PFTs' characterization from space, with examples of the main models and a discussion of achievements, gaps and future perspectives.     

Potential Environmental Applications of Pure Zeolitic Material Synthesized from Fly Ash

A pure 4A∕X (60∕40) zeolite product was synthesized from silica extracts of the Meirama fly ash in northwestern Spain. A high cation-exchange capacity (4.7 meq∕g) was obtained for the zeolitic material. The potential application of this coal fly ash conversion product for decontamination of high heavy metal waters was evaluated using three high heavy metal waters from acid mine drainage around the pyrite Huelva belt. The results were compared with those obtained with an equivalent pure commercial synthetic zeolite. A considerable reduction in the heavy metal content was attained (Zn from 174 to <0.1 mg∕L, Cu from 36 to 0.1 mg∕L, Fe from 444 to 0.8 mg∕L, Mn from 74 to <0.1 mg∕L, Pb from 1.5 to <0.1 mg∕L, and Cd from 0.4 to <0.1 mg∕L), even in high Ca and Fe waters using zeolite doses from 5 to 30 mg∕L. Both precipitation and cation-exchange processes accounted for the reduction in the pollutant concentration in the treated waters. Leachable hazardous elements from coal fly ash, such as Mo, B, As, V, and Cr, were not fixed in the synthesis of pure zeolites from the silica extracts. Consequently, they did not restrict the potential applications of this material as an ion exchanger, unlike the zeolitic material obtained from fly ash by direct alkaline conversion.     

A middleware solution for integrating and exploring IoT and HPC capabilities

Even with the considerable advances in the development of middleware solutions, there is still a substantial gap in Internet of Things (IoT) and high-performance computing (HPC) integration. It is not possible to expose services such as processing, storage, sensing, security, context awareness, and actuating in a unified manner with the existing middleware solutions. The consequence is the utilization of several solutions with their particularities, thus requiring different skills. Besides that, the users have to solve the integration and all heterogeneity issues. To reduce the gap between IoT and HPC technologies, we present the JavaCá&Lá (JCL), a middleware used to help the implementation of distributed user-applications classified as IoT-HPC. This ubiquity is possible because JCL incorporates (1) a single application programming interface to program different device categories; (2) the support for different programming models; (3) the interoperability of sensing, processing, storage, and actuating services; (4) the integration with MQTT technology; and (5) security, context awareness, and actions services introduced through JCL application programming interface. Experimental evaluations demonstrated that JCL scales when doing the IoT-HPC services. Additionally, we identify that customized JCL deployments become an alternative when Java-Android and vice-versa code conversion is necessary. The MQTT brokers usually are faster than JCL HashMap sensing storage, but they do not perform distributed, so they cannot handle a huge amount of sensing data. Finally, a short example for monitoring moving objects exemplifies JCL facilities for IoT-HPC development.     

Critical analysis of Thailand’s past energy policies towards the development of a new energy policy

This research originated from the researchers’ participation in the Thai senate Committee on Energy. It studies energy strategies and guidelines for Thailand’s energy development in line with the country’s potential, its energy resources as well as the needs of the Thai people with the ultimate goal to help bring about sustainable energy development. The research found that continuing dependence on natural gas crisis will pose a major threat with sustainable development of energy. According to its current power development plans, Thailand will likely increase its dependence on natural gas. The country should therefore diversify the use of energy sources since over-dependence on a single fuel will create risks to energy security, especially security of the fuels used in the generation of electricity. It is imperative to increase promotion of measures for energy conservation and energy efficiency, including measures to reduce fuel consumption and switching to renewable energy.     

Enhancement of Commercial Antifungal Agents by Kojic Acid

Natural compounds that pose no significant medical or environmental side effects are potential sources of antifungal agents, either in their nascent form or as structural backbones for more effective derivatives. Kojic acid (KA) is one such compound. It is a natural by-product of fungal fermentation commonly employed by food and cosmetic industries. We show that KA greatly lowers minimum inhibitory (MIC) or fungicidal (MFC) concentrations of commercial medicinal and agricultural antifungal agents, amphotericin B (AMB) and strobilurin, respectively, against pathogenic yeasts and filamentous fungi. Assays using two mitogen-activated protein kinase (MAPK) mutants, i.e., sakAΔ, mpkCΔ, of Aspergillus fumigatus, an agent for human invasive aspergillosis, with hydrogen peroxide (H₂O₂) or AMB indicate such chemosensitizing activity of KA is most conceivably through disruption of fungal antioxidation systems. KA could be developed as a chemosensitizer to enhance efficacy of certain conventional antifungal drugs or fungicides.