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Microbial fuel cells (MFC) and microbial electrolysis cells (MEC) are developing as sustainable power source technologies that can be utilized for feasible wastewater treatment and hydrogen production. Hydrogen gas has immense potential as an ecologically adequate energy carrier for vehicles. MFC is bioelectrochemical process that utilize microorganism as the impetuses to oxidize organic and inorganic matter and create electricity, whereas MEC are a reactor for biohydrogen production by combining MFC and electrolysis. MEC and MFC have been the cleanest, eco-friendly, and efficient method for biohydrogen production. The basic mechanism and thermodynamic principles involved in the production of hydrogen have been discussed in brief. Effective factors influencing H2 production such as microbial population, electrodes, membrane, and substrate were elaborated and recent advances in the factors have been explored for the better understanding of developing MFC and MEC technology-based hydrogen generation. This review completes a brief outline of topical advances in the MFC, MEC setup, and different operational parameters which influencing hydrogen production (ionic strength, applied voltage, organic loading, and hydraulic retention time). The review describes the current challenges involved in the technology used and provides effective future perspectives for overcoming the limitations. [ABSTRACT FROM AUTHOR]

Patients with autoimmune rheumatic diseases with a previous infection by the SARS-CoV-2 virus have exaggerated responses to a single dose of COVID-19 vaccination as compared to fully vaccinated infection naive patients. The second dose is currently recommended at an extended gap after the infection, but the information available regarding response to the second dose in this subgroup is limited. Patients with AIRDs previously infected with COVID-19, who have received at least one dose of AZD1222/ChAdOx1 (n = 200) were included and stratified based on vaccine doses (V), and infection (I) into I + V, I + V + V, V + I, V + V + I. Anti-RBD (receptor binding domain) antibodies were compared across the four groups. In 49 patients of the I + V + V group (AZD12222), paired sera were compared for antibody levels and neutralization after each vaccine dose. Thirty patients with hybrid immunity after BBV152 and 25 with complete vaccination without infection were included as controls. The highest anti-RBD antibody levels were observed in the V + V + I group (18,219 ± 7702 IU/ml) with statistically similar titers in the I + V + V (10,392 ± 8514 IU/ml) and the I + V (8801 ± 8122 IU/ml). This was confirmed in the 49 paired samples that paradoxically showed a lowering of antibody titers after the second dose [9626 (IQR: 4575–18,785)–5781 (2484–11,906); p < 0.001]. Neutralization of the Delta variant was unaffected but Omicron neutralization was significantly reduced after the second dose [45.7 (5.3–86.53)–35% (7.3–70.9); p = 0.028]. Ancillary analyses showed that only the hybrid immune sera could neutralize the Omicron variant and AZD1222 hybrids performed better than BBV152 hybrids. The second dose of AZD1222 did not boost antibody titers in patients with RD who had COVID-19 previously. In the analysis of paired sera, the second dose led to a statistically significant reduction in antibody titers and also reduced neutralization of the Omicron variant. [ABSTRACT FROM AUTHOR]

Water pollution and fossil fuels are major issues in the context of climate change. Photocatalysis research is rising to develop green technologies for the remediation of pollutants and for energy production. Photocatalysis converts the light energy as photons into chemical energy using semiconducting materials. Different methods are utilised to synthesise these photocatalytic materials. Metal and coupled metal frameworks are applied for the production of photocatalytic materials. Here we review the synthesis and applications of photocatalysts for environmental decontamination and for production of biodiesel, methanol and hydrogen. Pollutants include dyes, pesticides, herbicides, phenols and antibiotics. [ABSTRACT FROM AUTHOR]

The synthesis of silver nanoparticles (AgNPs) using Annona muricata (A. muricata) leaf extract and its larvicidal, metabolic enzyme inhibitory properties was demonstrated here. The AgNPs were synthesized and analyzed by using UV-visible spectroscopy and observed a maximum absorbance peak at 420 nm which corresponds to the AgNPs. The XRD analysis showed the 2θ intense values (111, 200, 220, and 311) within the ranges of Bragg's reflection; Fourier transform infrared spectroscopy (FTIR) showed that AgNPs were capped with alkanes, amides, and alkenes functional groups which act as a reducing, capping, and stabilizing agent; and field emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM) results indicated that synthesized AgNPs were spherical in shape with the size of 20–34 nm and energy-dispersive X-ray (EDX) spectroscopy exhibited a strong signal of silver. Various concentrations of AgNPs (6, 12, 18, 24, 30 μg mL−1) and aqueous leaf extract (ALE) (30, 60, 90, 120, 150 μg mL−1) were evaluated, and in all the concentrations, AgNPs showed significant larvicidal properties against three different second instar larvae, when compared to ALE. ALE exhibited LC50 and LC90 values of (LC50 45.521 μg/mL; LC90 456.406 μg/mL) against Ae. aegypti followed by An. stephensi (LC50 61.878 μg/mL; LC90 565.309 μg/mL) and Cx. quinquefasciatus (LC50 68.952 μg/mL; LC90 444.512 μg/mL), and AgNPs were exhibited LC50 and LC90 values (LC50 3.089 μg/mL; LC90 18.467 μg/mL) against Ae. aegypti followed by An. stephensi (LC50 3.155 μg/mL; LC90 39.888 μg/mL) and Cx. quinquefasciatus (LC50 5.188 μg/mL; LC90 31.660 μg/mL), respectively. The A. muricata leaf extract-mediated AgNPs were also evaluated for the first time to identify their metabolic enzyme inhibitory activity which also showed significant results. [ABSTRACT FROM AUTHOR]