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991.
Twenty algal-oligosaccharide-lysates (AOLs), derived from six agars and four algal polysaccharide extracts (APEs), were treated first with agarases with 250 or 500 agarase activity units (AU), which were produced from the agar-liquefying bacterial strain Pseudomonas vesicularis MA103, named MA103-agarases. The AOLs were then treated with agarases (250 or 500 AU) derived from the agar-softening bacterial strain Aeromonas salmonicida MAEF 108, named MAEF 108-agarases. Anti-oxidative properties of the AOLs were evaluated by five in vitro methods. The AOL obtained from the APE of Porphyra dentate, digested by 250 AU of MA 103-agarases, and by 250 AU of MAEF 108-agarases, designated as A250-Por, showed better results than the 19 other AOLs. This result is in accordance with the level of soluble total polyphenols (STP) of A250-Por, which was also higher than the remainder of the AOLs tested. The AOL derived from the APE of P. dentate, digested by 500 AU of MA103-agarases and then 500 AU of MAEF108-agarases, and designated as B500-Por, displayed the second highest data in four potential evaluation methods, except in H2O2 scavenging capacity. In this study, certain agars or APEs digested by specific agarases can present an increasing antioxidative capacity. These agars include Bitek agar, Agar powder, Bacteriological, Agar Bacteriological, and Guanghui agar, plus APEs of Gracilaria sp. and Monostroma nitidum decomposed stepwise by two agarases. The fraction of polyphenols (<1 kDa) that were derived from A250-Por showed anti-oxidative activities on α, α-diphenyl-β-picrylhydrazyl (DPPH) assay and reducing power determination, while the remaining four agar-lytic fractions obtained from A250-Por did not exhibit anti-oxidative activity. This phenomenon may suggest that anti-oxidative properties of AOLs originate in polyphenols. Algal-oligosaccharide-lysates may have potential use as a health food.  相似文献   
992.
菜稻菜轮作模式是由广东省农业科学院提出的一种高效利用并能改善土壤环境的耕作模式。为探讨菜稻菜模式对农田土壤重金属的影响,以蔬菜连作、水稻连作作为对照,在东莞市开展大田试验,研究菜稻菜模式下土壤Cd各赋存形态的分布特征、变化规律以及农作物可食部分对Cd含量的影响。结果表明,菜稻菜轮作和蔬菜连作对Cd全量及赋存形态无明显影响,水稻连作处理能降低耕层土壤Cd全量、可交换态、可氧化态、残渣态含量;土壤中Cd大多以活性较高的形态存在,各赋存形态的含量高低顺序为可交换态可还原态可氧化态残渣态,土壤中Cd可还原态能与可氧化态、残渣态进行相互转化;水稻对Cd的富集能力要远高于蔬菜,在推广菜稻菜模式时要慎重考虑水稻Cd的超标风险。  相似文献   
993.
通过近两年在江西省北部的瑞昌市武蛟乡、湖口县武山镇和九江县永安乡试验基地开展棉花与早熟西瓜套作高效栽培试验,结果表明:在丘陵旱地栽2行棉花1行西瓜,棉花的株距45cm,双行间距60cm,密度12345株/hm2,西瓜的株距46cm,密度6000株/hm2,其配置模式效益最佳。其籽棉产量4147.9kg/hm2,西瓜产量为26250kg/hm2,两者产值达113592.5元,h0。  相似文献   
994.
构建外源ABA处理大麦胚的均一化cDNA文库是利用酵母双杂交方法筛选与靶蛋白相互作用蛋白的前提条件。为给大麦抗逆基因的研究及抗逆转基因大麦材料的创制奠定基础,利用5μmol·L-1ABA和蒸馏水分别处理大麦种子0h、6h、12h、24h,剥取大麦的胚,用热酚法提取总RNA,利用SMART原理进行反转录PCR并进行均一化处理获得ds-cDNA。经SfiⅠ酶切的ds-cDNA与pGADT7-Rec载体连接后,转化大肠杆菌感受态细胞DH10B构建文库。结果表明,文库的容量为1.1×106,插入片段大于1 000bp,集中在1 000~3 000bp之间,符合酵母双杂交文库的要求。  相似文献   
995.
There are many major causes of cancer death, including metastasis of cancer. Dihydroaustrasulfone alcohol, which is isolated from marine coral, has shown antioxidant activity, but has not been reported to have an anti-cancer effect. We first discovered that dihydroaustrasulfone alcohol provided a concentration-dependent inhibitory effect on the migration and motility of human non-small cell lung carcinoma (NSCLC) A549 cells by trans-well and wound healing assays. The results of a zymography assay and Western blot showed that dihydroaustrasulfone alcohol suppressed the activities and protein expression of matrix metalloproteinase (MMP)-2 and MMP-9. Further investigation revealed that dihydroaustrasulfone alcohol suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. Dihydroaustrasulfone alcohol also suppressed the expression of PI3K and the phosphorylation of Akt. Furthermore, dihydroaustrasulfone alcohol markedly inhibited tumor growth in Lewis lung cancer (LLC)-bearing mice. We concluded that dihydroaustrasulfone alcohol is a new pure compound with anti-migration and anti-tumor growth activity in lung cancer and might be applied to clinical treatment in the future.  相似文献   
996.
The mechanism for how fucoxanthin (FX) suppressed adipose accumulation is unclear. We aim to investigate the effects of FX on metabolic rate and expressions of genes related to thermogenesis, mitochondria biogenesis and homeostasis. Using a 2 × 2 factorial design, four groups of mice were respectively fed a high sucrose (50% sucrose) or a high-fat diet (23% butter + 7% soybean oil) supplemented with or without 0.2% FX. FX significantly increased oxygen consumption and carbon dioxide production and reduced white adipose tissue (WAT) mass. The mRNA expressions of peroxisome proliferator-activated receptor (PPAR) γ coactivator-1α (PGC-1α), cell death-inducing DFFA-like effecter a (CIDEA), PPARα, PPARγ, estrogen-related receptor α (ERRα), β3-adrenergic receptor (β3-AR) and deiodinase 2 (Dio2) were significantly upregulated in inguinal WAT (iWAT) and epididymal WAT (eWAT) by FX. Mitochondrial biogenic genes, nuclear respiratory factor 1 (NRF1) and NRF2, were increased in eWAT by FX. Noticeably, FX upregulated genes of mitochondrial fusion, mitofusin 1 (Mfn1), Mfn2 and optic atrophy 1 (OPA1), but not mitochondrial fission, Fission 1, in both iWAT and eWAT. In conclusion, dietary FX enhanced the metabolic rate and lowered adipose mass irrespective of the diet. These were associated with upregulated genes of the PGC-1α network and mitochondrial fusion in eWAT and iWAT.  相似文献   
997.
The core-shell monodisperse P(St-MAA) microspheres with different diameters ranging from 200 nm to 400 nm were prepared by soap-free emulsion copolymerization, in which styrene (St) and methacrylic acid (MAA) were polymerizable monomers, and ammonium persulfate (APS) acted as initiator. The diameters and monodispersity of P(St-MAA) microspheres could be controlled by adjusting the concentrations of styrene, methacrylic acid and ammonium persulfate. The core-shell structure and chemical component distribution of the P(St-MAA) microspheres were confirmed by TEM and XPS. The photonic crystals on polyester fabrics with three-dimensionally ordered arrangement were fabricated by self-assembly of gravitational sedimentation with P(St-MAA) microspheres and exhibited brilliant structural colors without any chemical dyes and pigments. SEM, TEM and crystallographic analysis were applied to confirm a face centered cubic (fcc) structure of the photonic crystals on polyester fabrics. The versatile structural colors of the photonic crystals were dependent on the photonic band-gap which could be regulated by the spherical size of P(St-MAA) microspheres and viewing angles. This technology may provide a new strategy to color the fabrics and reduce the pollution in the current textile industry.  相似文献   
998.
999.
AD-2-1 is an antitumor fungal mutant obtained by diethyl sulfate mutagenesis of a marine-derived Penicillium purpurogenum G59. The G59 strain originally did not produce any metabolites with antitumor activities in MTT assays using K562 cells. Tracing newly produced metabolites under guidance of MTT assay and TLC analysis by direct comparison with control G59 extract, seven new (1–7) and two known (8–9) lipopeptides were isolated together with five known polyketides 10–14 from the extract of mutant AD-2-1. Structures of the seven new compounds including their absolute configurations were determined by spectroscopic and chemical evidences and named as penicimutalides A–G (1–7). Seven known compounds were identified as fellutamide B (8), fellutamide C (9), 1′-O-methylaverantin (10), averantin (11), averufin (12), nidurufin (13), and sterigmatocystin (14). In the MTT assay, 1–14 inhibited several human cancer cell lines to varying extents. All the bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses demonstrated that the production of 1–14 in the mutant AD-2-1 was caused by the activated production of silent metabolites in the original G59 fungal strain. Present results provided additional examples for effectiveness of the chemical mutagenesis strategy using diethyl sulphate mutagenesis to discover new compounds by activating silent metabolites in fungal isolates.  相似文献   
1000.
Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs) and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways.  相似文献   
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