Researchers assessed the morphophysiological, biochemical and antioxidant responses of purslane grown in an outdoor green wall. The nanoparticle treatments were designated N1 for silver, N2 for titanium dioxide and N3 for the combined application. Magnetic-pellet treatments comprised Level 1, designated M1, and Level 2, designated M2, while M3 was the control pellet condition.

The significant nanoparticle-by-pellet interaction showed that performance depended on the particular pairing rather than only on whether nanoparticles or pellets were present independently. The N1M1 pairing, combining silver nanoparticles with Level 1 magnetic pellets, produced the highest growth index at 25,000 cm³. This was 595% greater than the lowest-performing combination, N3M3, which registered 3,598 cm³.

N3M1, consisting of the combined nanoparticle treatment and Level 1 magnetic pellets, produced the maximum root surface area of 99.27 cm² and the maximum root dry weight of 1.96 g. These were measured outcomes from the outdoor experiment and add an underground component to the comparison among treatment pairs. Proline accumulation provided a contrasting biochemical result.

Silver nanoparticles without magnetic pellets, N1M3, produced the highest proline concentration at 1.60 mg g⁻¹ fresh weight. The authors interpreted this as an emergency adaptive response to nanoparticle-induced stress. When Level 1 magnetic pellets were added to the silver treatment, creating N1M1, proline decreased to 1.40 mg g⁻¹ fresh weight.

The authors associated this change with metabolic energy being redirected toward vegetative growth. TiO₂ nanoparticles paired with Level 1 magnetic pellets produced the most balanced overall vegetative performance. The N2M1 treatment achieved the highest total chlorophyll content at 9.73 μg mg⁻¹, the maximum total biomass of 22.96 g and the highest total soluble-protein content.

It also had the lowest reported malondialdehyde concentration, 0.17 μmol g⁻¹ fresh weight, which the researchers used as an indicator of lipid peroxidation. Thus, N2M1 combined high biomass and chlorophyll measurements with low measured lipid peroxidation, while N1M1 achieved the largest growth index. Other physiological indicators were associated with magnetic-pellet application.

The study reports improved relative water content, reduced electrolyte leakage and optimized activities of superoxide dismutase and guaiacol peroxidase. This result shows that the most prominent biochemical outcome varied among specific treatment pairings. At the plant-canopy level, combined applications markedly improved canopy coverage, survival duration and visual quality compared with the control.

The investigators identified high biomass production, prolonged leaf greenness and delayed cellular senescence as important characteristics in green-wall engineering. Within the conditions tested, the evidence points to N2M1 as the most balanced treatment, combining titanium dioxide nanoparticles with Level 1 magnetic pellets, and N1M1 as the treatment with the highest growth index. The findings are specific to the reported outdoor experiment on purslane and do not by themselves establish how the treatments would perform in other green-wall systems.

The authors nevertheless identified synergistic nanoparticle and magnetic-pellet application as an effective strategy for improving plant health, durability and visual quality in urban vertical green infrastructure.

Subject of Research: Effects of metallic nanoparticles and magnetic pellets on purslane grown in outdoor vertical green walls.

Article Title: Metallic nanoparticles and magnetic pellets synergistically optimize growth, antioxidant defense, and visual quality of Portulaca oleracea L. in urban vertical green walls

Article References: Jozay, M., Tehranifar, A., Berahmand, A., & Feizi, H. (2026). Metallic nanoparticles and magnetic pellets synergistically optimize growth, antioxidant defense, and visual quality of Portulaca oleracea L. in urban vertical green walls. BMC Plant Biology. https://doi.org/10.1186/s12870-026-09794-y

Image Credits: AI Generated

DOI: 10.1186/s12870-026-09794-y

Keywords: purslane, vertical green walls, titanium dioxide nanoparticles, silver nanoparticles, magnetic pellets, plant growth, chlorophyll, antioxidant defense, lipid peroxidation, urban greening, Metallic, nanoparticles

The researchers analyzed daily pediatric respiratory outpatient visits alongside daily concentrations of 12 PM₂.₅-bound metals and meteorological variables in Shijiazhuang. A generalized additive model was used to estimate short-term lagged associations for each metal, and a quantile g-computation model assessed the joint association of metal mixtures with outpatient visits. The models were also used to examine whether associations differed by sex and age.

The individual-metal analysis considered exposure over lags from zero to seven days, allowing the researchers to assess associations across the days surrounding changes in measured concentrations. Several metal elements were significantly associated with increased pediatric respiratory outpatient visits. For the total number of visits, an interquartile-range increase in lead concentration corresponded to a 13.188% increase, with a 95% confidence interval of 9.157% to 17.369%.

Zinc had the next-largest reported association: an interquartile-range increase corresponded to a 9.685% increase in total visits, with a 95% confidence interval of 5.612% to 13.915%. Lead showed the strongest association with acute upper respiratory infections, with an estimated excess risk of 24.510%. These estimates describe statistical associations in the study data and include uncertainty expressed through the reported confidence intervals; the study did not test whether the associations were causal.

The mixture analysis found that combined exposure to eight metals was associated with a 1.041-fold increase in outpatient risk for each decile increase in combined exposure, corresponding to an estimated 4.1% increase. The 95% confidence interval for the fold estimate was 1.023 to 1.059. Lead and chromium contributed the highest weights to this combined association.

The researchers found no statistically significant differences in metal associations between boys and girls. Zinc, however, differed significantly between the two age groups examined, with a stronger association among children aged 7 to 14 years. Thus, the age-stratified results suggest that the relationship between zinc and outpatient visits may differ across age groups, whereas the sex-stratified analysis did not detect statistically significant modification.

Because the study was observational and focused on daily ambient PM₂.₅ exposure and pediatric respiratory outpatient visits in one city over four years, its estimates are subject to the limitations of this design. The findings therefore support the conclusion that metallic components of PM₂.₅ are associated with increased pediatric respiratory outpatient visits in Shijiazhuang, with lead, zinc and chromium emerging as particularly relevant components. The authors’ conclusion calls for priority to be given to reducing lead and chromium emissions and for differentiated health-protection strategies for school-aged children and girls, while the reported evidence itself concerns short-term associations rather than proof of causal effects.

Subject of Research: Short-term associations between PM₂.₅-bound metals and pediatric respiratory outpatient visits in Shijiazhuang

Article Title: Effects of metallic components in ambient PM₂.₅ on pediatric respiratory diseases in Shijiazhuang

Article References: Du, X., Xu, N., Guan, M., Zhang, X., Chen, S., Tian, Z., Wu, L., Xu, M., & Chen, F. (2026). Effects of metallic components in ambient PM₂.₅ on pediatric respiratory diseases in Shijiazhuang. BMC Public Health. https://doi.org/10.1186/s12889-026-29760-5

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29760-5

Keywords: PM₂.₅, metallic components, pediatric respiratory health, outpatient visits, lead exposure, zinc exposure, chromium, air pollution, Shijiazhuang, Effects, metallic, components