Effectiveness of simultaneous foliar application of Zn and Mn or P to reduce Cd concentration in rice grains: a field study.

Excess cadmium (Cd) in agricultural soils can be taken up by rice plants and concentrated in the grain, presenting a human health risk. In this study, we field tested the effects of three foliar treatments (zinc (Zn) alone, or combined with manganese (ZnMn) or phosphorus (ZnP)) on the Cd concentration and grain yield of six rice cultivars (C Liangyou 7, Fengyuanyou 272, Xiangwanxian 12, Tianyouhuazhan, Xiangwanxian 13, and Jinyou 284) at the grain filling stage. Our results showed that rice yield and Cd, Zn, Mn, P, and K concentrations were significantly different among the cultivars (p < 0.05); for example, Jinyou 284 recorded lower Cd levels than any other cultivar. Application of Zn, ZnMn, and ZnP had no significant effect on rice yield and Mn, P, and K concentrations for all cultivars. Compared with the control, Cd concentrations after treatment with Zn, ZnMn, and ZnP decreased by 19.03-32.55%, 36.63-55.78% (p < 0.05), and 25.72-49.10%, respectively, while Zn concentrations increased by 11.02-29.38%, 10.63-32.67%, and 11.97-36.82%, respectively. There was a significant negative correlation between Cd and Zn concentrations (p < 0.01). All three treatments increased Zn and reduced Cd concentration in rice grains, though ZnMn was most effective. Therefore, cultivar selection and Zn fertilizer application are effective strategies to minimize Cd concentration in rice grains. However, the lowest result still exceeded the Chinese Cd safety limit (0.2 mg Cd kg-1) by a factor of 2.6, demonstrating that additional effective measures should be simultaneously used to further reduce the accumulation of Cd in rice grains.

Analysis of anti-inflammation mechanism of zukamu granules based on network pharmacology and hs-spme-gc-ms / 国际药学研究杂志

Objective: To explore the material basis and anti-inflammatory mechanisms of Zukamu granules (ZKMG)based on the headspace-solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GCMS) technique and network pharmacology analyses. Methods: HS-SPME-GC-MS technique was used to extract and identify the volatile components of ZKMG. Then combined with the non-volatile components obtained by literature retrieval, we constructed the main chemical composition table. The bioactive components were screened based on the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and their targets were predicted by the Swiss Target Prediction database. Thereafter, the anti-inflammatory-related targets were screened based on the Thera- peutic Targets Datebase and DrugBank with”Anti-inflammatory”as keyword. Then, the STRING database to analyze protein-protein interaction(PPI)and the software of Cytoscape 3.6.1 was used to construct the component-target-antiinflammatory target network. Finally, enrichment of function and signaling pathways of the target genes was conducted by Gene Ontology(GO)database and the Database for Annotation, Visualization and Integrated Discovery(DAVID). Re- sults: Thirty bioactive components including thymol, kaempferol and quercetin in ZKMG were screened out. Ninety-seven targets were predicted and AKR1B1, ALOX15, ALOX5, CYP1A2, EGFR, CHRM1, NOS3, PLA2G1B, PTGS2, BCHE were key anti-inflammatory targets. Sixty-eight pathways related to anti-inflammation were obtained by KEGG enrichment analysis, mainly including arachidonic acid metabolism, MAPK signaling pathway, inflammatory mediator regulation of TRP channels, IL-17 signaling pathway and NF-κB signaling pathway. Conclusion: This study focuses on the chemical constituents of ZKMG and network pharmacology to predict the material basis and pharmacological mecha- nism of their anti-inflammatory effect, which lays a good foundation for the verification of the later biological experiments and provides certain reference basis for the research on the anti-inflammation mechanism of other compound preparations.

Ultrasensitive sensing platform for platelet-derived growth factor BB detection based on layered molybdenum selenide-graphene composites and Exonuclease III assisted signal amplification.

A highly sensitive and ultrasensitive electrochemical aptasensor for platelet-derived growth factor BB (PDGF-BB) detection is fabricated based on layered molybdenum selenide-graphene (MoSe2-Gr) composites and Exonuclease III (Exo III)-aided signal amplification. MoSe2-Gr is prepared by a simple hydrothermal method and used as a promising sensing platform. Exo III has a specifical exo-deoxyribonuclease activity for duplex DNAs in the direction from 3' to 5' terminus, however its activity is limited on the duplex DNAs with more than 4 mismatched terminal bases at 3' ends. Herein, aptamer and complementary DNA (cDNA) sequences are designed with four thymine bases on 3' ends. In the presence of target protein, the aptamer associates with it and facilitates the formation of duplex DNA between cDNA and signal DNA. The duplex DNA then is digested by Exo III and releases cDNA, which hybridizes with signal DNA to perform a new cleavage process. Nevertheless, in the absence of target protein, the aptamer hybridizes with cDNA will inhibit the Exo III-assisted nucleotides cleavage. The signal DNA then hybridizes with capture DNA on the electrode. Subsequently, horse radish peroxidase is fixed on electrode by avidin-biotin reaction and then catalyzes hydrogen peroxide and hydroquinone to produce electrochemical response. Therefore, a bridge can be established between the concentration of target protein and the degree of the attenuation of the obtained signal, providing a quantitative measure of target protein with a broad detection range of 0.0001-1 nM and a detection limit of 20 fM.