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A method for the simultaneous determination of aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA) in animal blood and brain by two-dimensional liquid chromatography (2D-LC) combined with ultraviolet detection was established for the first time. First, the amino acid neurotransmitters (AANTs) were labeled on the corresponding fluorescent derivatives with 4-fluoro-7-nitrobenzofurazan (NBD-F), enriched on the extraction column and automatically transferred to the analytical column to achieve on-line extraction and complete separation of the target components. This method exhibited good selectivity, and the correlation coefficients for the analyte calibration curves of were > 0.99. The intra- and inter-day precisions were ≤ 16.03, and the accuracies were in the range of 70.59–116.20%. The system realizes the rapid detection and stability quantification of the five AANTs, which proves that the alternative dilution method is feasible. The results show that the system has high loading capacity, excellent resolution, and good peak shape and is not affected by other endogenous substances. Moreover, the developed method has been successfully applied to the analysis of biological samples in the blood and whole brain of rats and pigs. The content of AANTs in the hippocampus and cortex of rats was higher than that in those of pigs. This method is expected to provide applicability for the determination of AANTs in pharmacological, pharmaceutical and clinical research in nervous science.

Rationale Gelsemium elegans (G. elegans) is highly toxic to humans and rats but has insecticidal and growth-promoting effects on pigs and goats. However, the mechanisms behind the toxicity differences of G. elegans are unclear. Gelsenicine, isolated from G. elegans, has been reported to be a toxic alkaloid. Methods In this study, the in vitro metabolism of gelsenicine was investigated and compared for the first time using human (HLM), pig (PLM), goat (GLM) and rat (RLM) liver microsomes and high-performance liquid chromatography/mass spectrometry (HPLC/MS). Results In total, eight metabolites (M1-M8) were identified by using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC/QqTOF-MS). Two main metabolic pathways were found in the liver microsomes of the four species: demethylation at the methoxy group on the indole nitrogen (M1) and oxidation at different positions (M2-M8). M8 was identified only in the GLM. The degradation ratio of gelsenicine and the relative percentage of metabolites produced during metabolism were determined by high-performance liquid chromatography/tandem mass spectrometry (HPLC/QqQ-MS/MS). The degradation ratio of gelsenicine in liver microsomes decreased in the following order: PLM ≥ GLM > HLM > RLM. The production of M1 decreased in the order of GLM > PLM > RLM > HLM, the production of M2 was similar among the four species, and the production of M3 was higher in the HLM than in the liver microsomes of the other three species. Conclusions Based on these results, demethylation was speculated to be the main gelsenicine detoxification pathway, providing vital information to better understand the metabolism and toxicity differences of G. elegans among different species.

In this work, a novel solid-liquid interfacing triboelectric field based electroluminescence (SL-TEL) was proposed. When a droplet impacting on the SL-TEL device surface, specific textured green SL-TEL emit on the two cross-overlapped areas. As a coupling effect of solid-liquid interfacing triboelectrification and electroluminescence, the SL-TEL is essentially a type of electroluminescence excited by changing triboelectric field of droplet impact or wave scour. It relies on converting mechanical energy of liquid to visual light energy utilizing an intermediate triboelectric field without any electric power consumption. The SL-TEL device simply consist of three thin flexible layers, which is greatly simplifying the electroluminescent device structure and showing strong advantages of simple structure such as easy to integration and excellent stability. Experiments show that sequential liquid motions of droplet impinging on solid surface excite a corresponding dynamic series of electroluminescence patterns. The features of the electroluminescence also reveal the characteristics of liquid and the solid surface, such as contour edge of liquid spreading, capillary convergence of liquid at the apex (advancing and receding), and so on, which is capable of both sensing liquid leakage and displaying the dynamic information of droplets impacting motions.

Wearable and portable electronics for water environment application are of paramount significance, however restricted by its power source component. It remains a great challenge to simultaneously achieve ultra stretchability and high electric output performance for most energy harvesters in water. Herein, we report a high-performance stretchable liquid-solid contact electrification-based nanogenerator (S-LSNG) that enables water wave energy harvesting and subtle motion monitoring in water by an in-situ charged nanocomposite membrane. Notably, the effectively charged PTFE nanoparticles (100 nm) in this novel membrane can highly promote the output of S-LSNG. For the first time, the excellent stretchability (tensile strain, 200%), high output performance (open-circuit voltage of 120 V and short-circuit current of 18 μA) and ultra-thin device structure (300 μm) were achieved simultaneously for a liquid-solid contact electrification-based nanogenerator. Besides, the output performance of S-LSNG barely changed even after 100000 submerging-emerging cycles. In addition, the application of motion monitoring for human body in water was also demonstrated, such as single finger motion sensing and complex motion sensing of multiple-fingers. Because of the excellent stretchability, output performance and durability, the S-LSNG would be extensively applied to a sustainable energy supplier for the stretchable and wearable electronics in water.

Harvesting water wave energy presents a significantly practical route to energy supply for self-powered wireless sensing networks. Here we report a networked integrated triboelectric nanogenerator (NI-TENG) as a highly adaptive means of harvesting energy from interfacing interactions with various types of water waves. Having an arrayed networking structure, the NI-TENG can accommodate diverse water wave motions and generate stable electric output regardless of how random the water wave is. Nanoscaled surface morphology consisting of dense nanowire arrays is the key for obtaining high electric output. A NI-TENG having an area of 100 × 70 mm2 can produce a stable short-circuit current of 13.5 μA and corresponding electric power of 1.03 mW at a water wave height of 12 cm. This merit promises practical applications of the NI-TENG in real circumstances, where water waves are highly variable and unpredictable. After energy storage, the generated electric energy can drive wireless sensing by autonomously transmi...

A biocide-free antifouling method on wetted insulating surfaces, enabled by the oscillation of electric potential generated by an integrated triboelectric wave harvester (I-TEWH) is reported. Distinct from previous studies that reported antifouling on conducting surfaces by applying an additional power source, this method achieves antifouling on insulating surfaces with zero-power consumption. The electric potential in the vicinity of a protected surface oscillates in large amplitude as a result of periodically accumulated free electrons on an underlying electrode. The dynamic flow of the free electrons is driven by the I-TEWH that converts ambient wave energy by solid–liquid interface triboelectrification. As a consequence, the oscillating electric potential disturbs the inherent charge distribution on microbes due to electrostatic induction, preventing their initial adhesion onto the protected surface and thus prohibiting the subsequent formation of macroorganisms. Significant anti-adhesion efficiencies of as high as 99.3%, 99.1%, and 96.0% are achieved for negative-gram bacteria (Escherichia coli), positive-gram bacteria (Staphylococcus aureus), and diatoms (bacillariophyceze), respectively, on a smooth surface. The antifouling efficiency on a roughened surface with micro/nanostructures can be further enhanced by another 75%. This approach can be potentially utilized in coastal constructions, offshore facilities, and vessels that are either moving or stationary in port.