Microalgae-enhanced bioremediation of Cr(VI) ions using spent coffee ground-derived magnetic biochar MoS2-Ag composites.

Composites of magnetic biochar derived from spent coffee grounds were prepared using MoS2 decorated by plasmonic silver nanoparticles (MoS2-Ag), which were used for the bioremediation Cr6+ ions. The composites were characterized by electron microscopy, X-ray diffraction, Raman, and UV-VIS spectroscopy. The bioremediation of Cr6+ ions was enhanced almost two times compared to microalgae, Spirulina maxima. Such an increased activity is attributed to heterojunction formation of Biochar@MoS2-Ag composite due to the synergetic effects of surface plasmon resonance of AgNPs inducing amplified local electric field, thus simultaneously increasing the absorption of MoS2 under visible or near-infrared light. The combination of Biochar@MoS2-Ag and Spirulina maxima powder was effective for the separation (microalga-based absorption and accumulation of Cr6+ ions) of photo-induced carriers (composite-assisted to breakdown Cr6+ ions). This study offers efficient eco-friendly treatment of Cr6+ ions by reporting the first enhanced bioremediation of Cr(VI) ions by microalgae using MoS2-Ag-modified biochar obtained from consumed coffee grounds.

Effect of Vitamin D supplementation to reduce respiratory infections in children and adolescents in Vietnam: A randomized controlled trial.

BACKGROUND: It is uncertain whether vitamin D can reduce respiratory infection. OBJECTIVE: To determine whether vitamin D supplementation reduces influenza and other upper viral respiratory tract infections. METHODS: A total of 1300 healthy children and adolescents between the ages of 3 and 17 years were randomized to vitamin D (14 000 U weekly) or placebo for 8 months in Vietnam. The primary outcome was reverse transcriptase (RT)-PCR-confirmed influenza infection, and the coprimary outcome was multiplex PCR-confirmed non-influenza respiratory viruses. Participants, caregivers, and those assessing outcomes were blinded to group assignment. RESULTS: A total of 650 children and adolescents were randomly assigned to vitamin D and 650 to placebo. The mean baseline serum 25-hydroxyvitamin D levels were 65.7 nmol/L and 65.2 nmol/L in the intervention and placebo groups, respectively, with an increase to 91.8 nmol/L in the vitamin D group and no increase, 64.5 nmol/L, in the placebo group. All 1300 participants randomized contributed to the analysis. We observed RT-PCR-confirmed influenza A or B occurred in 50 children (7.7%) in the vitamin D group and in 43 (6.6%) in the placebo group (hazard ratio [HR]: 1.18, 95% CI: 0.79-1.78). RT-PCR-confirmed non-influenza respiratory virus infection occurred in 146 (22.5%) in the vitamin D group and in 185 (28.5%) in the placebo group (hazard ratio [HR]: 0.76, 95% CI: 0.61-0.94). When considering all respiratory viruses, including influenza, the effect of vitamin D in reducing infection was significant, HR: 0.81, 95% CI: 0.66-0.99. CONCLUSION: Vitamin D supplementation did not reduce the incidence of influenza but moderately reduced non-influenza respiratory viral infection.