Triboiontronics with temporal control of electrical double layer formation

Abstract The nanoscale electrical double layer plays a crucial role in macroscopic ion adsorption and reaction kinetics. In this study, we achieve controllable ion migration by dynamically regulating asymmetric electrical double layer formation. This tailors the ionic-electronic coupling interface, leading to the development of triboiontronics. Controlling the charge-collecting layer coverage on dielectric substrates allows for charge collection and adjustment of the substrate-liquid contact electrification property. By dynamically managing the asymmetric electrical double layer formation between the dielectric substrate and liquids, we develop a direct-current triboiontronic nanogenerator. This nanogenerator produces a transferred charge density of 412.54 mC/m2, significantly exceeding that of current hydrovoltaic technology and conventional triboelectric nanogenerators. Additionally, incorporating redox reactions to the process enhances the peak power and transferred charge density to 38.64 W/m2 and 540.70 mC/m2, respectively

Integrated transcriptomics and metabolomics provides insights into the Nicotiana tabacum response to heat stress

Heat stress is a prevalent factor that significantly damages crops, especially with the ongoing global warming and increasing frequency of extreme weather events. Tobacco is particularly sensitive to temperature fluctuations, experiencing reduced yield and quality under high temperatures. However, the underlying molecular mechanisms of heat resistance in tobacco remain poorly understood. This study comprehensively analyzed biochemical, transcriptomic, and metabolomic responses to heat stress on the root and shoot of the tobacco cultivar K326 compared to control conditions. Heat stress significantly increased the activities of antioxidant enzymes (CAT, POD, and SOD) and levels of osmotic mediators (soluble sugars, sucrose, and proline) in the shoot. Furthermore, transcriptome analysis identified 13,176 differentially expressed genes (DEGs) in the root (6,129 up-regulated and 7,047 down-regulated) and 12,283 DEGs (6,621 up-regulated and 5,662 down-regulated) in the shoot. The root had 24 enriched KEGG pathways, including phenylpropanoid metabolism, while the shoot had 32 significant pathways, such as galactose metabolism and MAPK signaling. The metabolomic data identified 647 metabolites in the root and 932 in the shoot, with carbohydrates and amino acids being the main categories. The root had 116 differentially abundant metabolites (DAMs) (107 up-regulated and 9 down-regulated), and the shoot contained 256 DAMs (251 up-regulated and 5 down-regulated). Joint transcriptome and metabolome analysis showed that galactose metabolism and starch and sucrose metabolism were co-enriched in both tissues. In contrast, amino sugar and nucleotide sugar metabolism was enriched in the root, and purine metabolism in the shoot. The purine metabolic pathway in the shoot can modulate the expression of MYB transcription factors by influencing ABA synthesis and signaling, thereby controlling the accumulation of HSPs, raffinose, sucrose, and trehalose to enhance heat tolerance. Furthermore, NtMYB78, an MYB transcription factor, enhances tolerance for heat stress in tobacco. This research offers a foundational framework for investigating and implementing heat-resistant genes and metabolic pathways in the root and shoot of tobacco seedlings

Hypokalemia Duration in the First Year Associated with Subsequent Peritoneal Dialysis-Associated Peritonitis: A Multicenter Retrospective Cohort Study

Background: The association of hypokalemia (LK) with peritoneal dialysis-associated peritonitis (PDAP) risk remains uncertain. Here, we calculated LK duration in the first PD year and evaluated its association with PDAP. Methods: A multicenter, retrospective, incident cohort study of 1633 participants was conducted from January 2008 to October 2020 in China. The duration of LK and severe hypokalemia (SLK) was calculated as the total number of months that a patient’s serum potassium (SK) level was less than 3.5 or 3.0 mEq/L during the first PD year. The study outcome was the risk of subsequent PDAP started in the second year and later. Cox proportional hazards models and competing risk models were used to assess the association. Results: The subsequent PDAP occurred in 420 (25.7%) participants during a median of 28 months of follow-up. Overall, LK duration in the first year was positively associated with a subsequent PDAP risk (per 3-month increments, adjusted HR, 1.13; 95%CI: 1.05–1.23). After categorization, patients with LK duration longer than 6 months had the highest adjusted HR of 1.53 (p = 0.005 vs. those without LK) for subsequent PDAP risk. A similar trend was also found for SLK duration. In a competing risk model, a similar trend was also observed. None of the variables, including demographic and PD characteristics, diabetes history, and several clinical measurements, significantly modified this association. The causative organisms of PDAP were similar to those previously reported. Conclusions: PD patients with longer LK duration in the first year had a higher subsequent PDAP risk

High-frequency mechanical energy harvester with direct current output from chemical potential difference

As an energy harvester that converts mechanical power into electrical energy, a triboelectric nanogenerator (TENG) with a pair of metallic and insulating electrodes can generate only the displacement current (Idis) in the electrodes, whereas a chemical potential difference generator (CPG) with a pair of semiconducting or/and metallic electrodes can generate both Idis and conduction current (Icon). Considering the effects of motion parameters on Idis and Icon is important for harvesting different mechanical energies in practical scenarios; the output characteristics of CPGs and traditional TENGs under different external resistance (R), contact-separation frequency (f), and maximum separation distance (xm) were systematically studied for the first time in this work. More interestingly, a direct current (DC) output can be generated directly by CPGs under R > 10 Mω or f > 100 Hz. This work not only provides a guideline for collecting different mechanical energies but also promotes the development of CPGs as an energy harvester and self-powered vibration sensor in the semiconductor industry.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)This project is financially supported by National Key Research and Development Program of China for Young Scientists (2021YFF0603500), National Natural Science Foundation of China (11974266 and U21A20147), Fundamental Research Funds for the Central Universities (WUT:2022IVA061, E1E46802), A*STAR AME IRG Grant SERC A1983c0027, and MOE AcRF Tier2 (2018-T2-2-005), Singapore