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31.
Barley yellow dwarf (BYD) is one of the most common diseases of cereal crops, caused by the phloem‐limited, cereal aphid‐borne Barley yellow dwarf virus (BYDV) (Luteoviridae). Delayed planting and controlling aphid vector numbers with insecticides have been the primary approaches to manage BYD. There is limited research on nitrogen (N) application effects on plant growth, N status, and water use in the BYDV pathosystem in the absence of aphid control. Such information will be essential in developing a post‐infection management plan for BYDV‐infected cereals. Through a greenhouse study, we assessed whether manipulation of N supply to BYDV‐infected winter wheat, Triticum aestivum L. (Poaceae), in the presence or absence of the aphid vector Rhopalosiphum padi L. (Hemiptera: Aphididae), could improve N and/or water uptake, and subsequently promote plant growth. Similar responses of shoot biomass and of water and N use efficiencies to various N application rates were observed in both BYDV‐infected and non‐infected plants, suggesting that winter wheat plants with only BYDV infection may be capable of outgrowing infection by the virus. Plants, which simultaneously hosted aphids and BYDV, suffered more severe symptoms and possessed higher virus loads than those infected with BYDV only. Moreover, in plants hosting both BYDV and aphids, aphid pressure was positively associated with N concentration within plant tissue, suggesting that N application and N concentration within foliar tissue may alter BYDV replication indirectly through their influence on aphid reproduction. Even though shoot biomass, tissue N concentration, and water use efficiency increased in response to increased N application, decision‐making on N fertilization to plants hosting both BYDV and aphids should take into consideration the potential of aphid outbreak and/or the possibility of reduced plant resilience to environmental stresses due to decreased root growth.  相似文献   
32.
Granulosa Cells (GCs) are sensitive to excessive production of reactive oxygen species (ROS). Quercetin (QUR) is a free radical scavenger which can alleviate oxidative stress through nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/antioxidant response element (ARE) pathway and thioredoxin (Trx) system. We aimed to explore the probable protective role of QUR on cultured human GCs treated with hydrogen peroxide (H2O2) as an inducer of oxidative stress. MTT assay was applied for evaluating the cell cytotoxicity of QUR and H2O2. The rate of apoptotic cells and intracellular ROS generation were determined by Annexin V-FITC/PI staining and 2′-7′-dichlorodihydro?uorescein diacetate ?uorescent probes (DCFH-DA), respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and western blot analysis were used to evaluate the gene and protein expression of Nrf2 and kelch-like ech-associated protein 1 (Keap1)1. The Nrf2 and Trx activities were measured by Enzyme-linked Immunosorbent Assay (ELISA). The results indicated that QUR pretreatment can decrease ROS production and apoptosis induced by H2O2. In addition, QUR increased Nrf2 gene and protein expression, as well as its nuclear translocation. Moreover, in QUR-treated group, a lower level of Keap1 protein was observed, which was not reported as significant. The results also indicated a significant correlation between the expression of Nrf2 and Keap1 in QUR-treated group. Further, QUR protected GCs from oxidative stress by increasing Trx gene expression and activity. This study suggests that QUR as a supplementary factor may protect GCs from oxidative stress in diseases related to this condition.  相似文献   
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Although phenanthridine has been frequently used as a specific substrate for the assessment of aldehyde oxidase activity, the use of this method is questionable due to a lower limit of detection and its validity for kinetic studies. In the present study, a novel sensitive multivariate calibration method based on partial least squares (PLS) has been developed for the measurement of aldehyde oxidase activity using phenanthridine as a substrate. Phenanthridine and phenanthridinone binary mixtures were prepared in a dynamic linear range of 0.1–30.0 μM and the absorption spectra of the solutions were recorded in the range of 210–280 nm in Sorenson's phosphate buffer (pH 7.0) containing EDTA (0.1 mM). The optimized PLS calibration model was used to calculate the concentration of each chemical in the prediction set. Hepatic rat aldehyde oxidase was partially purified and the initial oxidation rates of different concentrations of phenanthridine were calculated using the PLS method. The values were used for calculating Michaelis–Menten constants from a Lineweaver–Burk double reciprocal plot of initial velocity against the substrate concentration. The limits of detection for phenanthridine and phenanthridinone were found to be 0.04 ± 0.01 and 0.03 ± 0.01 μM (mean ± SD, n = 5), respectively. Using this method, the Km value for the oxidation of phenanthridine was calculated as 1.72 ± 0.09 μM (mean ± SD, n = 3). Thus, this study describes a novel spectrophotometric method that provides a suitable, sensitive and easily applicable means of measuring the kinetics of phenanthridine oxidation by aldehyde oxidase without the need for expensive instrumentation.  相似文献   
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The preparation, properties, and application in adriamycin delivery ofbiocompatible and biodegradable poly(lactide-co-glycolide)-polyethylene glycol (PLGA-PEG) nanoparticles are discussed. PLGA-PEG copolymers were synthesized by ring opening polymerization of the dl-lactide and glycolide in the presence of PEG1000. 1H-NMR and FT-IR spectrum were consistent with the structure of PLGA-PEG copolymers. The adriamycin-loaded nanoparticles could be prepared using a precipitation-solvent evaporation technique. The nanoparticles have been produced by a precipitation-solvent evaporation technique. The physical characteristics and drug loading efficiency of the PLGA-PEG nanoparticles were influenced by the composition of the PLGA-PEG copolymers used to prepare the nanoparticles. Particle sizes were between 65 and 100 nm for different compositions of PLGA-PEG copolymers. PLGA-PEG nanoparticles prepared from copolymers having relatively high PLGA/PEG ratios were smaller. Entrapment efficiency was 25%-33%. Adriamycin release from the nanoparticles at pH 7.4 showed an initial burst release and then sustained release phase. These results showed that PLGA-PEG nanoparticles could be an effective carrier for cancer therapy.  相似文献   
37.
Considering the unfavourable response of breast cancer (BC) to treatment, we assessed the therapeutic potential hesperidin in mice bearing 4T1 BC tumours. Anti-tumour effects were assessed by measuring pathologic complete response (pCR), survival analysis, immunohistochemistry for E-cadherin, VEGF, MMP9, MMP2 and Ki-67, serum measurement of IFNγ and IL-4, and gene expression analysis of CD105, VEGFa, VEGFR2 and COX2. Survival of tumour-bearing mice was the highest in mice receiving a combination of hesperidin and doxorubicin (Dox) (80%) compared to the normal saline (43%), hesperidin 5 (54%), 10 (55.5%), 10 (60.5%) and 40 (66%) mg/kg, and 10 mg/kg Dox-treated (73%) groups (p < 0.0001 for all). Compared to the normal saline group, there was a significant elevation in IFNγ level in the animals receiving 20 (p = 0.0026) and 40 (p < 0.001) mg/kg hesperidin, 10 mg/kg Dox (p < 0.001), and combined hesperidin (20 mg/kg) and Dox (10 mg/kg) (p < 0.001). A significant reduction in the gene expression of CD 105 (p = 0.0106), VEGFa (p < 0.0001), VEGFR2 (p < 0.0001), and Cox2 (p = 0.034) and a significant higher pCR score (p = 0.006) were noticed in mice treated with 10 mg/kg Dox + 20 mg/kg hesperidin compared to those treated with 10 mg/kg Dox alone. Immunohistochemical staining showed significant reductions in Ki-67 (p < 0.001) and VEGF (p < 0.001) and a significant elevation in E-cadherin (p = 0.005) in the 10 mg/kg Dox + 20 mg/kg treatment group than in 10 mg/kg Dox alone group. Hesperidin can be considered as a potentially suitable anti-cancer agent for BC that can synergize with other chemotherapeutics.  相似文献   
38.
Two novel copper (II) complexes [Cu(TFP)(Gly)Cl] ⋅ 2H2O complex ( 1 ) and [Cu(TFP)(His)Cl] ⋅ 2H2O complex ( 2 ) are synthesized, where TFP stands for trifluropromazine, Gly. represents glycine, and His. is histidine. Chemical composition, IR, mass spectra, and magnetic susceptibility tests are performed. Complex binding with macromolecules was investigated using UV-vis, viscosity, gel electrophoresis, and fluorescence quenching. Fluorescence spectroscopy revealed that each complex could replace ethidium bromide (EB). These complexes exhibit grooved, non-covalent, and electrostatic interactions with CT-DNA. Spectroscopy analysis of the BSA interaction showed that complexes bind to protein (Kb values for ( 1 ) is 5.89×103 M−1 and for ( 2 ) is 9.08×103 M−1) more strongly than CT-DNA (Kb values for ( 1 ) is 5.43×103 M−1 and for ( 2 ) is 7.17×103 M−1). Molecular docking analysis and spectral absorption measurements showed high agreement. Antimicrobial, antioxidant, and anti-inflammatory properties were tested in vitro. The druggability of complex ( 2 ) should be tested in vivo as it is more biologically active.  相似文献   
39.
Nano-structure Cu(II) complex [Cu(AMAB)2]Cl2 with Schiff base (AMAB) derived from the condensation between 4-(dimethylamino)benzaldehyde and amoxicillin trihydrate was prepared. (AMAB) Schiff base and its Cu(II) complex were identified and confirmed by different physicochemical techniques. The Schiff base (AMAB) was coordinated to copper ion through carbonyl oxygen and imine nitrogen donor sites. X-ray powder diffraction shows a cubic crystal system of the Cu(II) complex. The density functional theory was used to optimize the structure geometries of the investigated compounds. The molecular docking of the active amino acids of the investigated proteins' interactions with the tested compounds was evaluated. The bactericidal or bacteriostatic effect of the compounds was screened against some bacterial strains. The activity of Cu-chelate against Gram-negative bacteria was mainly more effective than its (AMAB) ligand and vice versa in the case of Gram-positive bacteria. The biological activity of the prepared compounds with biomolecules calf thymus DNA (CT-DNA) was determined by electronic absorption spectra and DNA gel electrophoresis technique. All studies revealed that the Cu-chelate derivative exhibited better binding affinity to both CT-DNA than the AMAB and amoxicillin itself. The anti-inflammatory effect of the designed compounds was determined by testing their protein denaturation inhibitory activity spectrophotometrically. All obtained data supported that the designed nano-Cu(II) complex with Schiff base (AMAB) is a potent bactericide against H. pylori, and exhibits anti-inflammatory activity. The dual inhibition effects of the designed compound represent a modern therapeutic approach with extended spectrum of action. Therefore, it can act as good drug target in antimicrobial and anti-inflammtory therapies. Finally, H. pylori resistance to amoxicillin is absent or rare in many countries, thus amoxicillin nanoparticles may be beneficial for countries where amoxicillin resistance is reported.  相似文献   
40.
Cancer is one of main health public problems worldwide. Several factors are involved in beginning and development of cancer. Genetic and internal/external environmental factors can be as important agents that effect on emerging and development of several cancers. Diet and nutrition may be as one of important factors in prevention or treatment of various cancers. A large number studies indicated that suitable dietary patterns may help to cancer prevention or could inhibit development of tumor in cancer patients. Moreover, a large numbers studies indicated that a variety of dietary compounds such as curcumin, green tea, folat, selenium, and soy isoflavones show a wide range anti‐cancer properties. It has been showed that these compounds via targeting a sequence of cellular and molecular pathways could be used as suitable options for cancer chemoprevention and cancer therapy. Recently, dietary microRNAs and exosomes have been emerged as attractive players in cancer prevention and cancer therapy. These molecules could change behavior of cancer cells via targeting various cellular and molecular pathways involved in cancer pathogenesis. Hence, the utilization of dietary compounds which are associated with powerful molecules such as microRNAs and exosomes and put them in dietary patterns could contribute to prevention or treatment of various cancers. Here, we summarized various studies that assessed effect of dietary patterns on cancer prevention shortly. Moreover, we highlighted the utilization of dietary compounds, dietary microRNAs, and dietary exosomes and their cellular and molecular pathways in cancer chemoprevention.  相似文献   
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