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881.
The aim of this research was to determine the chemical composition of the essential oils of Dahlia pinnata, their insecticidal activity against Sitophilus zeamais and Sitophilusoryzae and to isolate insecticidal constituents. Based on bioactivity-guided fractionation, active constituents were isolated and identified as d-limonene, 4-terpineol and α-terpineol. Essential oils and active compounds tested exhibited contact toxicity, with LD50 values ranging from 132.48 to 828.79 μg/cm2 against S. zeamais and S. oryzae. Essential oils possessed fumigant toxicity against S. zeamais and S. oryzae with LC50 from 14.10 to 73.46 mg/L. d-Limonene (LC50 = 4.55 and 7.92 mg/L) showed stronger fumigant toxicity against target insects. 4-Terpineol (88 ± 8%) and d-limonene (87 ± 5%) showed the strongest repellency against S. zeamais and S. oryzae, respectively. The results indicate that essential oils and insecticidal constituents have potential for development into natural fumigants, insecticides or repellents for control of the stored-product insect pests.  相似文献   
882.
Bioaccumulation of penta-BDE(DE-71) in earthworms(Eisenia fetida) and the induced toxicities on the growth and reproduction of earthworms were investigated.All the major congeners in DE-71 could be bioaccumulated in earthworms and the concentration found in earthworms correlated to the spiked concentration in soil.DE-71 might inhibit the growth and reproduction of cocoons and juveniles of earthworms.The toxicities were dose dependent and increased with exposure time.Exposing earthworms to combination of DE-...  相似文献   
883.
总结了32例老年人心梗病例,就其临床特点进行了分析,并指出了心脏康复的重要性。  相似文献   
884.
Acute kidney injury (AKI) is a dose-limiting side effect of cisplatin therapy in cancer patients. However, effective therapies for cisplatin-induced AKI are not available. Oxidative stress, tubular cell death, and inflammation are known to be the major pathological processes of the disease. 6-Shogaol is a major component of ginger and exhibits anti-oxidative and anti-inflammatory effects. Accumulating evidence suggest that 6-shogaol may serve as a potential therapeutic agent for various inflammatory diseases. However, whether 6-shogaol exerts a protective effect on cisplatin-induced renal side effect has not yet been determined. The aim of this study was to evaluate the effect of 6-shogaol on cisplatin-induced AKI and to investigate its underlying mechanisms. An administration of 6-shogaol after cisplatin treatment ameliorated renal dysfunction and tubular injury, as shown by a reduction in serum levels of creatinine and blood urea nitrogen and an improvement in histological abnormalities. Mechanistically, 6-shogaol attenuated cisplatin-induced oxidative stress and modulated the renal expression of prooxidant and antioxidant enzymes. Apoptosis and necroptosis induced by cisplatin were also suppressed by 6-shogaol. Moreover, 6-shogaol inhibited cisplatin-induced cytokine production and immune cell infiltration. These results suggest that 6-shogaol exhibits therapeutic effects against cisplatin-induced AKI via the suppression of oxidative stress, tubular cell death, and inflammation.  相似文献   
885.
Papain-like protease is an essential enzyme in the proteolytic processing required for the replication of SARS-CoV-2. Accordingly, such an enzyme is an important target for the development of anti-SARS-CoV-2 agents which may reduce the mortality associated with outbreaks of SARS-CoV-2. A set of 69 semi-synthesized molecules that exhibited the structural features of SARS-CoV-2 papain-like protease inhibitors (PLPI) were docked against the coronavirus papain-like protease (PLpro) enzyme (PDB ID: (4OW0). Docking studies showed that derivatives 34 and 58 were better than the co-crystallized ligand while derivatives 17, 28, 31, 40, 41, 43, 47, 54, and 65 exhibited good binding modes and binding free energies. The pharmacokinetic profiling study was conducted according to the four principles of the Lipinski rules and excluded derivative 31. Furthermore, ADMET and toxicity studies showed that derivatives 28, 34, and 47 have the potential to be drugs and have been demonstrated as safe when assessed via seven toxicity models. Finally, comparing the molecular orbital energies and the molecular electrostatic potential maps of 28, 34, and 47 against the co-crystallized ligand in a DFT study indicated that 28 is the most promising candidate to interact with the target receptor (PLpro).  相似文献   
886.
Selenium is an essential component of glutathione peroxidase and other enzyme systems and is therefore essential for animal metabolism. It is, however, toxic at concentrations little above those required for health. Some plants accumulate selenium from seleniferous soils and constitute a toxic hazard to grazing stock. The more complex organic selenium compounds that occur naturally in plants, animals and microorganisms have been characterized following their isolation or partial isolation, and have often been identified by their similarity to analogous sulphur compounds. The occurrence and identification ­of selenium compounds in biological samples and methods for their analysis are reviewed. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
887.
Rice grass has been reported to contain bioactive compounds that possess antioxidant and free-radical scavenging activities. We aimed to assess rice grass extract (RGE) drink by determining catechin content, free-radical scavenging and iron-binding properties, as well as toxicity in cells and animals. Young rice grass (Sukhothai-1 strain) was dried, extracted with hot water and lyophilized in a vacuum chamber. The resulting extract was reconstituted with deionized water (260 mg/40 mL) and served as Sukhothai-1 rice grass extract drink (ST1-RGE). HPLC results revealed at least eight phenolic compounds, for which the major catechins were catechin, epicatechin and epigallocatechin-3-gallate (EGCG) (2.71–3.57, 0.98–1.85 and 25.47–27.55 mg/40 mL serving, respectively). Elements (As, Cu, Pb, Sn and Zn) and aflatoxin (B1, B2, G1 and G2) contents did not exceed the relevant limits when compared with WHO guideline values. Importantly, ST1-RGE drink exerted radical-scavenging, iron-chelating and anti-lipid peroxidation properties in aqueous and biological environments in a concentration-dependent manner. The drink was not toxic to cells and animals. Thus, Sukhothai-1 rice grass product is an edible drink that is rich in catechins, particularly EGCG, and exhibited antioxidant, free radical scavenging and iron-binding/chelating properties. The product represents a functional drink that is capable of alleviating conditions of oxidative stress and iron overload.  相似文献   
888.
Among trichothecenes, T-2 toxin is the most toxic fungal secondary metabolite produced by different Fusarium species. Moreover, T-2 is the most common cause of poisoning that results from the consumption of contaminated cereal-based food and feed reported among humans and animals. The food and feed most contaminated with T-2 toxin is made from wheat, barley, rye, oats, and maize. After exposition or ingestion, T-2 is immediately absorbed from the alimentary tract or through the respiratory mucosal membranes and transported to the liver as a primary organ responsible for toxin''s metabolism. Depending on the age, way of exposure, and dosage, intoxication manifests by vomiting, feed refusal, stomach necrosis, and skin irritation, which is rarely observed in case of mycotoxins intoxication. In order to eliminate T-2 toxin, various decontamination techniques have been found to mitigate the concentration of T-2 toxin in agricultural commodities. However, it is believed that 100% degradation of this toxin could be not possible. In this review, T-2 toxin toxicity, metabolism, and decontamination strategies are presented and discussed.  相似文献   
889.
A new dicoumarin, jusan coumarin, (1), has been isolated from Artemisia glauca aerial parts. The chemical structure of jusan coumarin was estimated, by 1D, 2D NMR as well as HR-Ms spectroscopic methods, to be 7-hydroxy-6-methoxy-3-[(2-oxo-2H-chromen-6-yl)oxy]-2H-chromen-2-one. As the first time to be introduced in nature, its potential against SARS-CoV-2 has been estimated using various in silico methods. Molecular similarity and fingerprints experiments have been utilized for 1 against nine co-crystallized ligands of COVID-19 vital proteins. The results declared a great similarity between Jusan Coumarin and X77, the ligand of COVID-19 main protease (PDB ID: 6W63), Mpro. To authenticate the obtained outputs, a DFT experiment was achieved to confirm the similarity of X77 and 1. Consequently, 1 was docked against Mpro. The results clarified that 1 bonded in a correct way inside Mpro active site, with a binding energy of −18.45 kcal/mol. Furthermore, the ADMET and toxicity profiles of 1 were evaluated and showed the safety of 1 and its likeness to be a drug. Finally, to confirm the binding and understand the thermodynamic characters between 1 and Mpro, several molecular dynamics (MD) simulations studies have been administered. Additionally, the known coumarin derivative, 7-isopentenyloxycoumarin (2), has been isolated as well as β-sitosterol (3).  相似文献   
890.
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