Azolla Pinnata: Sustainable Floating Oil Cleaner of Water Bodies.

Various plant-based materials effectively absorb oil contaminants at the water/air interface. These materials showcase unparalleled efficiency in purging oil contaminants, encompassing rivers, lakes, and boundless oceans, positioning them as integral components of environmental restoration endeavors. In addition, they are biodegradable, readily available, and eco-friendly, thus making them a preferable choice over traditional oil cleaning materials. This study explores the phenomenal properties of the floating Azolla fern (Azolla pinnata), focusing on its unique hierarchical leaf surface design at both the microscale and nanoscale levels. These intricate structures endow the fern with exceptional characteristics, including superhydrophobicity, high water adhesion, and remarkable oil or organic solvent absorption capabilities. Azolla's leaf surface exhibits a rare combination of dual wettability, where hydrophilic spots on a superhydrophobic base enable the pinning of water droplets, even when positioned upside-down. This extraordinary property, known as the parahydrophobic state, is rare in floating plants, akin to the renowned Salvinia molesta, setting Azolla apart as a natural wonder. Submerged in water, Azolla leaves excel at absorbing light oils at the air-water interface, demonstrating a notable ability to extract high-density organic solvents. Moreover, Azolla's rapid growth, doubling in the area every 4-5 days, especially in flowing waters, positions it as a sustainable alternative to traditional synthetic oil-cleaning materials with long-term environmental repercussions. This scientific lead could pave the way for more environmentally friendly approaches to mitigate the negative impacts of oil spills and promote a cleaner water ecosystem.

Synergetic Role of Nano-/Microscale Structures of the Trifolium Leaf Surface for Self-Cleaning Properties.

Wetting has an essential pertinence to surface applications. The exemplary water-repelling and self-cleaning surfaces in nature have stimulated considerable scientific exploration, given their practical leverage in cleaning window glasses, painted surfaces, fabrics, and solar cells. Here, we explored the three-tier hierarchical surface structure of the Trifolium leaf with distinguished self-cleaning characteristics. The leaf remains fresh, withstands adverse weather, thrives throughout the year, and self-cleans itself against mud or dust. Self-cleaning features are attributed to a three-tier hierarchical synergetic design. The leaf surface is explicated by an optical microscope, a scanning electron microscope, a three-dimensional profilometer, and a water contact angle measuring device. Hierarchical base roughness (i.e., nano-/microscale) comprises a fascinating arrangement, which imparts a superhydrophobic feature to the surface. As a result, the contaminants present on the leaf surface are washed with rolling water droplets. We noticed that self-cleaning is a function of impacting or rolling droplets, and the rolling mechanism is identified as efficient. The self-cleaning phenomenon is studied for contaminations of variable sizes, shapes, and compositions. The contaminations are supplied in both dry and aqueous mixtures. Furthermore, we examined the self-cleaning effect of the Trifolium leaf surface by atmospheric water harvesting. The captured water drops fuse, roll, descend, and wash away the contaminating particles. The diversity of contaminants investigated makes this study applicable to different environmental conditions. And, along with other parallel technologies, this investigation could be useful for crafting sustainable self-cleaning surfaces for regions with acute water scarcity.

Multiscale Janus Surface Structure of Trifolium Leaf with Atmospheric Water Harvesting and Dual Wettability Features.

Numerous fascinating hierarchical surfaces from nature, including cactus spines, rice leaves, Namib desert beetle, spider silks, and pitcher plants, have been thoroughly investigated to emulate and architect superior surfaces for capturing sustainable, clean, and safe freshwater from the atmosphere. Hitherto, the adaxial side of biological surfaces has been meticulously investigated for wettability and atmospheric water harvesting (AWH) applications. However, the abaxial face has not yet attracted much scientific scrutiny. Here, we revealed the multifunctional Janus surface traits of Trifolium pratense (i.e., red clover) leaf with extrusive atmospheric water fishing ability on both adaxial and abaxial faces. Water harvesting is performed by conical outgrowths (microhairs). The individual hair's intriguing topography comprises asymmetric shape and surface roughness, which plays synergetic roles in water deposition and directional transport. The water collection quantity on the leaf surface is a function of hair density, which varies significantly on two sides. Noticeably, instead of gravitational pull, the hairs perform water reaping competence under the collective impact of surface energy and Laplace pressure gradients. Consequently, both straight-up and upside-down water harvesting are presented. Furthermore, the leaf surface exhibits dual water wettability features. The upper side manifests the water-repelling and water roll-off phenomenon. In contrast, the lower surface displays a water-retaining/or pinning effect. Optical microscopy, scanning electronic microscopy, real-time optical visualization, and contact angle analysis were employed to characterize the natural and template specimens. The dorsiventral asymmetry of the Trifolium leaf examined in this work could be helpful for a plethora of applications, such as scalable AWH, rainwater collection, self-cleaning, and adhesive fixtures.

Biodeterioration studies of thermoplastics in nature using indigenous bacterial consortium

Thermoplastics, poly vinyl chloride and low-density polyethylene were treated in the presence of indigenously developed bacterial consortium in laboratory and natural conditions. The consortium was developed using four bacteria, selected on the basis of utilization of PVC as primary carbon source, namely P. otitidis, B. aerius, B. cereus and A. pedis isolated from the plastic waste disposal sites in Northern India. The comparative in-vitro treatment studies as revealed by the spectral and thermal data, illustrated the relatively better biodegradation potential of developed consortium for PVC than the LDPE. Further, the progressive treatments of both the thermoplastics were conducted for three months under natural conditions. For this purpose, bioformulation of consortium was prepared and characterized for the viability up to 70 days of storage at 25±1ºC. The consortium treated polymer samples were monitored through SEM and FT-IR spectroscopy. Analytical data revealed the biodeterioration potential of the developed consortium for PVC and LDPE, which could help in disposing the plastic waste.

Heterozygotes of NOS3 polymorphisms contribute to reduced nitrogen oxides in high-altitude pulmonary edema.

STUDY OBJECTIVES: High-altitude pulmonary edema (HAPE), which develops on exertion under hypoxic conditions, aggravates due to endothelial dysfunction. Repeat events of the disorder suggests of genetic susceptibility. Endothelial nitric oxide synthase gene (NOS3), a regulator of vasodilation, has emerged as a strong candidate marker. In the present study, we investigated G894T, 27-base-pair 4b/4a (variable number of tandem repeat), -922A/G, and -786T/C polymorphisms of NOS3, individually or in combination, for an association with HAPE. DESIGN: A cross-sectional case control study. SETTINGS: Blood samples of HAPE-resistant lowlanders (HAPE-r) were obtained at sea level, and blood samples of patients with HAPE (HAPE-p) were obtained at Sonam Norboo Memorial Hospital, Leh, at 3,500 m. PARTICIPANTS: The study groups consisted of 60 HAPE-r inducted two to three times to altitudes > 3,600 m; and 72 HAPE-p, who had HAPE on their first visit to high altitude. RESULTS: Nitrogen oxides (NOx) at 77.9 +/- 28.6 micromol/L were significantly elevated in HAPE-r as compared to 42.39 +/- 12.93 micromol/L in HAPE-p (p < 0.0001). Genotype distribution of G894T and 4b/4a polymorphisms was significantly different in the two groups (p = 0.001 and 0.009, respectively). Haplotype analysis revealed -922A/G and -786T/C polymorphisms in complete linkage disequilibrium. The wild-type haplotypes G-b (G894T, 4b/4a), G-A (G894T, -922A/G), and G-b-A (G894T, 4b/4a, -922A/G) were significantly overrepresented in HAPE-r (p < 0.0001, p = 0.03, and p = 0.02, respectively). The heterozygote genotype combination GTba as compared to wild-type combination GGbb was significantly higher in HAPE-p (chi2 = 18.62, p = 0.00009; odds ratio, 7.20; 95% confidence interval, 2.82 to 18.38). The combination of four heterozygotes GTbaAGTC was overrepresented in HAPE-p (p = 0.04), whereas the wild-type genotype combination GGbbAATT was overrepresented in HAPE-r (p = 0.002). Furthermore, the GGbb combination correlated with significantly elevated NOx as compared to remaining combinations as a whole in both HAPE-r and HAPE-p (p = 0.01 and 0.004, respectively). CONCLUSIONS: Reduced NOx and combination of heterozygotes associate with the susceptibility to HAPE. The study impels another step toward application of NOx as a diagnostic marker for HAPE. The NOS3 GTba and GTbaAGTC genotype combinations may find application as genetic markers for predicting the risk for HAPE.