Phytoremediation: green to clean environmental heavy metal pollution

Many natural processes and anthropogenic activities lead to the persistent accumulation of non-biodegradable heavy metals in the environment. This contamination further has the potential to enter the food chain by a process called bioaccumulation and further, the concentration of heavy metal raises exponentially from lower to higher trophic levels as it is consumed called biomagnification. With the perspective of the consequences associated with heavy metal toxicity including risks to ecosystem and human health (mutagenic, carcinogenic, and teratogenic), the reclamation of toxic accumulates in soil and water is of paramount importance. Presently, clean-up technologies for heavy metals primarily concentrate on mitigating toxicity using physicochemical and mechanical methods such as soil incineration, excavation, landfilling, soil washing, solidification, and the application of electric fields. However, these are expensive, time-consuming, and also result in destructive changes to soil's physicochemical and biological properties, causing secondary pollution to the soil ecosystem. Therefore, the use of the inherent plant’s ability to absorb ionic compounds even at low concentrations near the soil-root interface can be effectively employed as a strategy to extract and remove or lower the bioavailable toxic metals and this phenomenon is called phytoremediation

Growth of CuCl thin films by magnetron sputtering for ultraviolet optoelectronic applications

Copper (I) chloride (CuCl) is a potential candidate for ultraviolet (UV) optoelectronics due to its close lattice match with Si (mismatch less than 0.4%) and a high UV excitonic emission at room temperature. CuCl thin films were deposited using radio frequency magnetron sputtering technique. The influence of target to substrate distance (dts) and sputtering pressure on the composition, microstructure, and UV emission properties of the films were analyzed. The films deposited with shorter target to substrate spacing (dts=3 cm) were found to be nonstoichiometric, and the film stoichiometry improves when the substrate is moved away from the target (dts=4.5 and 6 cm). A further increase in the spacing results in poor crystalline quality. The grain interface area increases when the sputtering pressure is increased from 1.1×10–³ to 1×10–² mbar at dts=6 cm. Room temperature cathodoluminescence spectrum shows an intense and sharp UV exciton (Z₃) emission at ~385 nm with a full width at half maximum of 16 nm for the films deposited at the optimum dts of 6 cm and a pressure of 1.1×10–³ mbar. A broad deep level emission in the green region (~515 nm) is also observed. The relative intensity of the UV to green emission peaks decreased when the sputtering pressure was increased, consistent with an increase in grain boundary area. The variation in the stoichiometry and the crystallinity are attributed to the change in the intensity and energy of the flux of materials from the target due to the interaction with the background gas molecules

Radiofrequency ablation in the treatment of paediatric microcystic lymphatic malformations

AbstractObjective:Congenital lymphatic malformations are a challenging clinical problem. There is currently no universally accepted treatment for the management of microcystic disease. We describe the novel use of an existing technology (radiofrequency ablation, also termed Coblation) for the debulking of paediatric microcystic lymphatic malformations involving the upper aerodigestive tract.Methods:Five children with microcystic or mixed-type lymphatic malformations were included in this retrospective case series.Results:Each child had a satisfactory outcome following radiofrequency debulking, with improved oral intake and airway symptoms. No serious complications were reported. These findings constitute level IV evidence.Conclusion:We recommend radiofrequency ablation as a safe, viable alternative to existing techniques for the treatment of paediatric microcystic lymphatic malformations of the upper aerodigestive tract. Radiofrequency ablation achieves effective debulking of microcysts whilst avoiding excessive bleeding and thermal damage to surrounding tissues. This paper constitutes the first report of successful treatment of airway obstruction due to paediatric laryngopharyngeal microcystic disease, using radiofrequency ablation.</jats:sec