The fluorescent carbon dot is a novel type of carbon nanomaterial. In comparison with semiconductor quantum dots and fluorescence organic agents, it possesses significant advantages such as excellent photostability and biocompatibility, low cytotoxicity and easy surface functionalization, which endow it a wide application prospect in fields of bioimaging, chemical sensing, environmental monitoring, disease diagnosis and photocatalysis as well. Biomass waste is a good choice for the production of carbon dots owing to its abundance, wide availability, eco-friendly nature and a source of low cost renewable raw materials such as cellulose, hemicellulose, lignin, carbohydrates and proteins, etc. This paper reviews the main sources of biomass waste, the feasibility and superiority of adopting biomass waste as a carbon source for the synthesis of carbon dots, the synthetic approaches of carbon dots from biomass waste and their applications. The advantages and deficiencies of carbon dots from biomass waste and the major influencing factors on their photoluminescence characteristics are summarized and discussed. The challenges and perspectives in the synthesis of carbon dots from biomass wastes are also briefly outlined.

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Cordycepin is one of the most important bioactive compounds produced by species of Cordyceps sensu lato, but it is hard to produce large amounts of this substance in industrial production. In this work, single factor design, Plackett-Burman design, and central composite design were employed to establish the key factors and identify optimal culture conditions which improved cordycepin production. Using these culture conditions, a maximum production of cordycepin was 2008.48 mg/L for 700 mL working volume in the 1000 mL glass jars and total content of cordycepin reached 1405.94 mg/bottle. This method provides an effective way for increasing the cordycepin production at a large scale. The strategies used in this study could have a wide application in other fermentation processes.

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In this study, soil containing four different concentrations of salt was used to grow Leymus chinensis, which was sampled over 120 days between the beginning of spring and the end of fall. During this time, its physiological and morphological characteristics were analyzed. Maximal superoxide dismutase and betaine content were observed under moderate saline‐alkaline stress treatment (A3), and with increasing saline‐alkaline stress, there was a linear increase in the contents of Na+, proline, malondialdehyde (MDA), organic acids (OAs), catalase, peroxidase, soluble protein and total soluble sugar. However, the K+ content and the K+/Na+ ratio decreased significantly. Under saline‐alkaline stress, the K+, betaine, OA and soluble protein levels in the leaves were higher than those in the rhizomes, whereas the proline, MDA, protective enzyme and total soluble sugar levels in the leaves were lower than those observed in the rhizomes. The node density varied with increases in saline‐alkali stress, and each node index was maximal at A3. Under saline‐alkali stress, the rhizome biomass, leaf biomass and root–shoot ratio first decreased and then increased, whereas the change in root biomass showed a contrary tendency, and the specific root length increased gradually. There was a significant correlation between the root–shoot ratio, specific root length, and the physiological indexes. These results show that under different degrees of saline‐alkali stress, L. chinensis is likely to use a series of adaptive physiological and morphological responses; the physiological responses were primarily related to the allocation of biomass and energy, root length, and the allocation of biomass between the aboveground and belowground organs.

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A simple method has been developed by combining high-performance liquid chromatography with diode array detection with the alternating trilinear decomposition method for simultaneous determination of four tyrosine kinase inhibitors in different human plasma samples. Chromatographic separation of the analytes was performed on a reversed-phase column with methanol (65%, v/v, A) and 0.1% aqueous solution of formic acid (35%, v/v, B). Analysis time was 5.0 min per run and analytes could be completely eluted within 2.8--3.8 min. The calibration concentration ranges of vandetanib, pazopanib, afatinib and dasatinib were designed as 0.50-6.10, 0.50-6.10, 0.70-7.00 and 0.70-7.00 μg·mL(-1), respectively. The intra- and inter-day RSDs ranged between 0.1 and 8.9%. Quantitative information could be extracted from the unsegregated interferences of different human plasma samples with the aid of the "second-order advantage" of three-way (second-order) calibration methods. All results demonstrated that the proposed method for direct quantitative analysis of four tyrosine kinase inhibitors in different complex systems possessed good characteristics of rapidity, sensitivity and efficiency, and it is expected to be an attractive choice in the fast analysis of clinical samples.

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