A Dual-Mode Triboelectric Nanogenerator for Efficiently Harvesting Droplet Energy.

Triboelectric nanogenerator (TENG) is a promising solution to harvest the low-frequency, low-actuation-force, and high-entropy droplet energy. Conventional attempts mainly focus on maximizing electrostatic energy harvest on the liquid-solid surface, but enormous kinetic energy of droplet hitting the substrate is directly dissipated, limiting the output performance. Here, a dual-mode TENG (DM-TENG) is proposed to efficiently harvest both electrostatic energy at liquid-solid surface from a droplet TENG (D-TENG) and elastic potential energy of the vibrated cantilever from a contact-separation TENG (CS-TENG). Triggered by small droplets, the flexible cantilever beam, rather than conventional stiff ones, can easily vibrate multiple times with large amplitude, enabling frequency multiplication of CS-TENG and producing amplified output charges. Combining with the top electrode design to sufficiently utilize charges at liquid-solid interface, a record-high output charge of 158 nC is realized by single droplet. The energy conversion efficiency of DM-TENG is 2.66-fold of D-TENG. An array system with the specially designed power management circuit is also demonstrated for building self-powered system, offering promising applications for efficiently harvesting raindrop energy.

Perceptions of medical error among general practitioners in rural China: a qualitative interview study.

BACKGROUND: Medical error (ME) is a serious public health problem and a leading cause of death. The reported adverse incidents in China were much less than western countries, and the research on patient safety in rural China's primary care institutions was scarce. This study aims to identify the factors contributing to the under-reporting of ME among general practitioners in township health centres (THCs). METHODS: A qualitative semi-structured interview study was conducted with 31 general practitioners working in 30 THCs across 6 provinces. Thematic analysis was conducted using a grounded theory approach. RESULTS: The understanding of ME was not unified, from only mild consequence to only almost equivalent to medical malpractice. Common coping strategies for THCs after ME occurs included concealing and punishment. None of the participants reported adverse events through the National Clinical Improvement System website since they worked in THCs. Discussions about ME always focused on physicians rather than the system. CONCLUSIONS: The low reported incidence of ME could be explained by unclear concept, unawareness and blame culture. It is imperative to provide supportive environment, patient safety training and good examples of error-based improvements to rural primary care institutions so that ME could be fully discussed, and systemic factors of ME could be recognised and improved there in the future.

Contact efficiency optimization for tribovoltaic nanogenerators.

Energy harvesters based on the tribovoltaic effect that can convert mechanical energy into electricity offer a potential solution for the energy supply of decentralized sensors. However, a substantial disparity in output current, exceeding 106 times, exists between micro- and macro-contact tribovoltaic nanogenerators (TVNGs). To tackle this challenge, we develop a quantification method to determine the effective contact efficiency of conventional large-scale TVNGs, revealing a mere 0.038% for a TVNG of 1 cm2. Thus, we implement an optimization strategy by contact interface design resulting in a remarkable 65-fold increase in effective contact efficiency, reaching 2.45%. This enhancement leads to a current density of 23 A m-2 and a record-high charge density of 660 mC m-2 for the TVNG based on Cu and p-type silicon. Our study reveals that increasing the effective contact efficiency will not only address the existing disparities but also have the potential to significantly enhance the output current in future advancements of large-scale TVNGs.

Sulfur dioxide promotes seed germination by modulating reactive oxygen species production in maize.

Sulfur dioxide (SO2) is generally considered to be toxic to cells, but recent studies have shown that SO2 has positive roles in stress defense responses in plants. However, whether SO2 functions as a signaling molecule in the developmental process, especially in seed germination, is yet to be studied. Here, we present data supporting the role of SO2 in seed germination and possible molecular mechanisms. SO2 treatment significantly promoted the seed germination and seed vigor in maize. The germinating seeds treated with SO2 treatment exhibited higher reactive oxygen species (ROS) levels and NADPH oxidase activities. Furthermore, the specific NADPH oxidase inhibitor diphenyleneiodinium (DPI) strongly inhibited ROS accumulations, and SO2-promoted seed germination and vigor. Meanwhile, α-Amylase activity and transcripts in germinating seeds treated with SO2 were significantly elevated. These data have demonstrated that NADPH oxidase-dependent ROS production contributes to the induction of α-Amylase activity, thereby promoting seed germination upon SO2 exposure. SO2 might function as a signaling molecule in plant growth and development, especially in seed germination. This study might provide a theoretical foundation for the potential exploitation of hydrated SO2 in seed germination control in crop management.

Application of xylitol on nitrogen removal from saline wastewater through "Candidatus Brocadia sinica"-dominated anammox process under low temperature.

Xylitol was first applied to enhance nitrogen removal from saline wastewater through "Candidatus Brocadia sinica"-dominated anammox process under low temperature. The reactor was maintained at 15°C, and the salinity of wastewater was 35 g/L. Ammonium removal rate (ARR) and nitrite removal rate (NRR) were stable at around 0.27 kg/(m3  d) without xylitol addition. As an osmotic pressure regulator and cryoprotective agent, optimal ARR and NRR were 0.51 kg/(m3  d) and 0.63 kg/(m3  d) at 0.3 mM xylitol. At the addition of 1 mM high-dosage xylitol, there existed dissimilatory reduction in nitrate to ammonium nitrogen and heterotrophic denitrification in the reactor. Remodified logistic model was suitable to simulate NH 4 + - N removal process with xylitol addition. As a result, xylitol dose should be controlled within 0.3 mM, which greatly promoted the nitrogen removal from saline wastewater under low temperature. PRACTITIONER POINTS: Xylitol could be used as osmotic pressure regulator and cryoprotective agent to enhance nitrogen removal. The optimal dose was achieved at 0.3 mM xylitol for "Candidatus Brocadia sinica" in low-temperature saline wastewater. High-dosage xylitol could interfere with nitrogen removal efficiency due to the presence of DNAR and HB. Remodified logistic model was suitable for the analysis and prediction of nitrogen removal process with xylitol addition.

Nitrogen and Phosphorus Co-doped Porous Carbon for High-Performance Supercapacitors.

As one of the most promising fast energy storage devices, supercapacitor has been attracting intense attention for many emerging applications. However, how to enhance the electrochemical performance of electrode materials is still the main issue among various researches. In this paper, hierarchical porous carbons derived from Eleocharis dulcis has been prepared by chemical activation process with the aid of KOH at elevated temperature. Results show that the N, P co-doped porous carbon exhibits excellent electrochemical performance, it owns a specific capacitance of 340.2 F/g at 1 A/g, and obtains outstanding cycling stability of 96.9% of capacitance retention at 10 A/g after 5,000 cycles in a three-electrode system. Moreover, in the two-electrode system, the product still maintains a high specific capacitance of 227.2 F/g at 1 A/g, and achieves good electrochemical cycle stability (94.2% of capacitance retention at 10 A/g after 10,000 cycles); besides, its power/energy density are 3694.084 and 26.289 Wh/kg, respectively. Therefore, the combination of facile synthesis strategy and excellent electrochemical performance makes Eleocharis dulcis-based porous carbon as a promising electrode material for supercapacitor.

Identification of a 119-bp Promoter of the Maize Sulfite Oxidase Gene (ZmSO) That Confers High-Level Gene Expression and ABA or Drought Inducibility in Transgenic Plants.

Drought adversely affects crop growth and yields. The cloning and characterization of drought- or abscisic acid (ABA)-inducible promoters is of great significance for their utilization in the genetic improvement of crop resistance. Our previous studies have shown that maize sulfite oxidase (SO) has a sulfite-oxidizing function and is involved in the drought stress response. However, the promoter of the maize SO gene has not yet been characterized. In this study, the promoter (ZmSOPro, 1194 bp upstream region of the translation initiation site) was isolated from the maize genome. The in-silico analysis of the ZmSOPro promoter identified several cis-elements responsive to the phytohormone ABA and drought stress such as ABA-responsive element (ABRE) and MYB binding site (MBS), besides a number of core cis-acting elements, such as TATA-box and CAAT-box. A 5' RACE (rapid amplification of cDNA ends) assay identified an adenine residue as the transcription start site of the ZmSO. The ZmSOPro activity was detected by ß-glucuronidase (GUS) staining at nearly all developmental stages and in most plant organs, except for the roots in transgenic Arabidopsis. Moreover, its activity was significantly induced by ABA and drought stress. The 5'-deletion mutant analysis of the ZmSOPro in tobacco plants revealed that a 119-bp fragment in the ZmSOPro (upstream of the transcription start site) is a minimal region, which is required for its high-level expression. Moreover, the minimal ZmSOPro was significantly activated by ABA or drought stress in transgenic plants. Further mutant analysis indicated that the MBS element in the minimal ZmSOPro region (119 bp upstream of the transcription start site) is responsible for ABA and drought-stress induced expression. These results improve our understanding of the transcriptional regulation mechanism of the ZmSO gene, and the characterized 119-bp promoter fragment could be an ideal candidate for drought-tolerant gene engineering in both monocot and dicot crops.