[Adsorption Performance of Walnut Green Husk Biochar for Heavy Metals].

The biochars of WP300, WP500, and WP700 were prepared by pyrolyzing walnut green husk under 300℃, 500℃, and 700℃ with the oxygen-free condition for removing Pb2+, Cu2+, and Cd2+ in an aqueous solution. The results revealed that WP500 prepared under the medium pyrolysis temperature achieved the best adsorption performance for heavy metals, and the highest removal efficiency was reached when the solution pH was 8, in which the removal efficiency of Pb2+, Cu2+, and Cd2+ were 97.87%, 99.78%, and 71.15%, respectively. The required biochar dosage for heavy metal removal varied under different adsorption conditions. In the single-metal system, the optimal dosage for WP500 in the Pb2+, Cu2+, and Cd2+ solutions was 1.3 g·L-1, 2.1 g·L-1, and 1.9 g·L-1, respectively, whereas in the pollution metals system, the optimal biochar dosage was 5.1 g·L-1. In addition, the adsorption capacity of WP500 for the three heavy metals followed the order of Pb2+>Cu2+>Cd2+ under the single and combined-metals system, indicating that there were no synergistic or antagonistic effects among these three adsorbates. The fitting results of the adsorption isotherm model suggested that various immobilization methods existed in adsorption process between WP500 and Pb2+, Cu2+, and Cd2+. The kinetic fitting results suggested that the main reaction between WP500 and Pb2+, Cu2+, and Cd2+ was chemical adsorption. The mechanisms of WP500 for heavy metals involved pore-filling, electrostatic attraction, ion-exchange, mineral precipitation, complexation, and π-π electron donor-accepter interaction. To conclude, this study offered a new insight for the resource utilization of the waste walnut green husk.

Rational Design of Esterase-Insensitive Fluorogenic Probes for In Vivo Imaging.

Small-molecule fluorogenic probes are indispensable tools for performing research in biomedical fields and chemical biology. Although numerous cleavable fluorogenic probes have been developed to investigate various bioanalytes, few of them meet the baseline requirements for in vivo biosensing for disease diagnosis due to their insufficient specificity resulted from the remarkable esterase interferences. To address this critical issue, we developed a general approach called fragment-based fluorogenic probe discovery (FBFPD) to design esterase-insensitive probes for in vitro and in vivo applications. With the designed esterase-insensitive fluorogenic probe, we successfully achieved light-up in vivo imaging and quantitative analysis of cysteine. This strategy was further extended to design highly specific fluorogenic probes for other representative targets, sulfites, and chymotrypsin. The present study expands the bioanalytical toolboxes available and offers a promising platform to develop esterase-insensitive cleavable fluorogenic probes for in vivo biosensing and bioimaging for the early diagnosis of diseases.

Diagnosis of Bacterial Plant Diseases via a Nitroreductase-Activated Fluorescent Sensor.

Plant diseases caused by bacteria have become one of the serious problems that threaten human food security, which led to the remarkable reduction of agricultural yields and economic loss. Nitroreductase (NTR), as an important biomarker, is highly expressed in bacteria, and the level of NTR is closely related to the progression of pathogen infection. Therefore, the design of small-molecule fluorescent sensors targeting NTR is of great significance for the detection and diagnosis of plant pathogenic bacteria. In this study, a new fluorescent sensor targeting NTR was discovered and then successfully applied to the imaging of zebrafish and pathogenic bacteria. Most importantly, the developed sensor achieved the real-time diagnosis of Brassica napus L. infected with bacteria, which provides a promising tool for examining the temporal and spatial infection of plant pathogens in precision agriculture.

In vivo fluorescent screening for HPPD-targeted herbicide discovery.

BACKGROUND: 4-Hydroxyphenylpyruvate dioxygenase (HPPD), playing a critical role in vitamin E and plastoquinone biosynthesis in plants, has been recognized as one of the most important targets for herbicide discovery for over 30 years. Structure-based rational design of HPPD inhibitors has received more and more research interest. However, a critical challenge in the discovery of new HPPD inhibitors is the common inconsistency between molecular-level HPPD-based bioevaluation and the weed control efficiency in fields, due to the unpredictable biological processes of absorption, distribution, metabolism, and excretion. RESULTS: In this study, we developed a fluorescent-sensing platform of efficient in vivo screening for HPPD-targeted herbicide discovery. The refined sensor has good capability of in situ real-time fluorescence imaging of HPPD in living cells and zebrafish. More importantly, it enabled the direct visible monitoring of HPPD inhibition in plants in a real-time manner. CONCLUSION: We developed a highly efficient in vivo fluorescent screening method for HPPD-targeted herbicide discovery. This discovery not only offers a promising tool to advance HPPD-targeted herbicide discovery, but it also demonstrates a general path to develop the highly efficient, target-based, in vivo screening for pesticide discovery. © 2022 Society of Chemical Industry.

[Organoids derived from the digestive system and their perspective applications in exercise physiology].

Organoid, formed from organ-specific cells, is a group of self-renewal and self-organizing cells growing in a 3-dimensional structure. With the recent progress on microenvironment regulation, stem cell differentiation and organ development, organoids have been constructed and used as promising tools for a wide range of multidisciplinary biomedical applications. Exercise disrupts the internal environment homeostasis, which brings a series of physiological alterations to the digestive system. The current animal or human models are necessary, but not sufficient to monitor the fluctuating microenvironment of gastrointestinal epithelial cells or hepatocytes during exercise. This review described the construction and application of digestive system organoids, as well as the effect of exercise on the microenvironment of intestinal epithelial cells and hepatocytes. The perspective applications of digestive system organoids in exercise physiology were also stated. Using organoid technologies, the possible mechanisms of the exercise-induced dynamic physiological changes would be explored in a new dimension.

RNA-binding protein Musashi2 stabilizing androgen receptor drives prostate cancer progression.

The androgen receptor (AR) pathway is critical for prostate cancer carcinogenesis and development; however, after 18-24 months of AR blocking therapy, patients invariably progress to castration-resistant prostate cancer (CRPC), which remains an urgent problem to be solved. Therefore, finding key molecules that interact with AR as novel strategies to treat prostate cancer and even CRPC is desperately needed. In the current study, we focused on the regulation of RNA-binding proteins (RBPs) associated with AR and determined that the mRNA and protein levels of AR were highly correlated with Musashi2 (MSI2) levels. MSI2 was upregulated in prostate cancer specimens and significantly correlated with advanced tumor grades. Downregulation of MSI2 in both androgen sensitive and insensitive prostate cancer cells inhibited tumor formation in vivo and decreased cell growth in vitro, which could be reversed by AR overexpression. Mechanistically, MSI2 directly bound to the 3'-untranslated region (UTR) of AR mRNA to increase its stability and, thus, enhanced its transcriptional activity. Our findings illustrate a previously unknown regulatory mechanism in prostate cancer cell proliferation regulated by the MSI2-AR axis and provide novel evidence towards a strategy against prostate cancer.