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911.
四君子汤体外抗脂质过氧化和活性氧自由基的作用 总被引:15,自引:2,他引:15
本研究观察了四君子汤体外对肝组织自发生成MDA、Fe2+-Vit C诱导心、肝、肾生成MDA、H2O2诱导红细胞溶血试验及对O2生成的影响。结果显示四君子汤能够明显抑制肝组织自发性和Fe2+-VitC体系诱导的心、肝、肾MDA生成(P<0.01),并能够明显抑制H2O2诱导的红细胞溶血(P<0.01),同时,对O2生成也有显著抑制作用(P<0.01),表明四君子汤在体外能够抑制或清除OH、O2、H2O2等自由基的生成,阻止自由基引发对生物膜的过氧化损伤。 相似文献
912.
913.
Regional selection of insecticides and fungal biopesticides to control aphids and thrips and improve the forage quality of alfalfa crops 下载免费PDF全文
PAN Fan GAO Li-jie ZHU Kai-hui DU Gui-lin ZHU Meng-meng ZHAO Li GAO Yu-lin TU Xiong-bing ZHANG Ze-hua 《农业科学学报》2023,22(1):185-194
The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa (aphids and thrips) were compared in three sites across China’s alfalfa belt. In addition, the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined. Efficacy varied among the different biological and chemical insecticides. The chemical insecticides were significantly more effective than biopesticides in a short time-frame. The efficacy period of biopesticides was significantly longer than that of chemical insecticides, and the corrected mortality rate of aphids in all regions was above 50% at 14 days after application. The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period. The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei. The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments. Compared with chemical insecticides, the yield of alfalfa hay was higher in the biopesticides treatments. Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides. This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China, and for reducing chemical insecticide usage and improving forage quality. 相似文献
914.
为了降低脲醛树脂胶黏剂的游离甲醛释放量,以俄罗斯落叶松浆粕为原料,利用酸水解,硅烷偶联剂改性等制备获得表面改性纳米结晶纤维素(M-NCC),并将M-NCC作为吸附材料用于脲醛树脂基材制备胶合板,研究M-NCC对脲醛树脂胶黏剂游离甲醛的吸附效果和机理。结果表明:透射电镜(TEM)检测可知,制备的NCC颗粒长度约为100~200 nm、直径约为20~30 nm,结晶度为57.3%,相比原始纤维素提高了41.1%;硅烷偶联剂3-(2-氨乙基)-氨丙基甲基二甲氧基硅烷(MCPS)使NCC的浸润性显著增强,当MCPS用量为8%时M-NCC接枝率达到27.2%,M-NCC对脲醛树脂的接触角为65.7°,下降32.7%;由扫描电镜(SEM)照片可观测到,表面改性显著改善了低浓度NCC颗粒在脲醛树脂基材中的分散状态,当M-NCC质量分数2%时,纳米颗粒的分散性能明显下降;M-NCC可有效吸附脲醛树脂基材中的游离甲醛,当M-NCC质量分数1.5%时可致游离甲醛比对照组(0.51 mg/L)下降50.9%。 相似文献
915.
Ataman Kose Nurullah Gunay Ali R. Ocak Abdullah T. Demiryurek 《Pesticide biochemistry and physiology》2010,97(3):249-255
Recent several studies have reported that oxidative stress could be an important component of the mechanism of cardiotoxicity due to organophosphate-induced toxicity. The aim of this study is to evaluate the oxidative and antioxidative parameters in cardiac toxicity of organophosphate poisoning, and determine the effects of atropine and pralidoxime on this parameters. The experimental groups were randomly divided into five groups as control (corn oil), dichlorvos (30 mg/kg), atropine (10 mg/kg), pralidoxime (40 mg/kg), and atropine (10 mg/kg) + pralidoxime (40 mg/kg) groups. Serum cholinesterase levels were suppressed with dichlorvos, and these reductions were inhibited with atropine and/or pralidoxime pretreatment. Serum, but not cardiac, total free sulfhydryl groups and paraoxonase activities were significantly increased in the pralidoxime group when compared to the control group. Serum arylesterase activities were elevated in the dichlorvos, atropine, pralidoxime, and atropine + pralidoxime groups when compared to the control group (P < 0.05). Total oxidant status, oxidative stress index, malondialdehyde and catalase activities in serum and cardiac tissues were not markedly different between the groups. No significant changes were also observed with cardiac myeloperoxidase and serum ceruloplasmin activities. In conclusion, these results showed that acute dichlorvos administration did not cause marked cardiac damage, and oxidative stress probably does not play a major role in dichlorvos-induced poisoning. On the other hand, especially pralidoxime treatment markedly increased the serum total free sulfhydryl groups, paraoxonase and arylesterase activities. However, the underlying mechanisms for these changes are not exactly known. 相似文献
916.
917.
用氨苄西林、阿莫西林、庆大霉素和阿米卡星 4种抗生素在体外作用大肠杆菌后 ,观察细菌菌量、形态变化及诱发内毒素释放的情况。结果表明 ,4种抗生素均对大肠杆菌有较好的杀菌作用 ,最小抑菌质量浓度分别为 2、2、1、0 .5mg/ L。氨苄西林和阿莫西林以不同浓度作用大肠杆菌后 ,可使菌体产生丝状体 ,尤其在 0 .5 MIC时 ,丝状体产生的量最为显著 ,这 2种药使菌体发生丝状变化的程度不一 ,尤以氨苄西林更甚。庆大霉素和阿米卡星作用大肠杆菌后 ,菌体形态未发生变化 ,但菌量明显下降。杀菌液中内毒素含量测定结果表明 ,氨苄西林和阿莫西林在不同浓度 (0 .5、2、4、8MIC)及不同作用时间 (0、2、4、6、8h)与对照组相比 ,均显著 (P<0 .0 5 )增加大肠杆菌内毒素的释放 ,且氨苄西林诱发内毒素释放的量显著 (P<0 .0 5 )高于阿莫西林 ,不同药物浓度诱发内毒素释放量的顺序为 0 .5 MIC>2 MIC>4 MIC>8MIC,不同作用时间内毒素释放量的顺序为 8h>6 h>4 h>2 h>0 h。庆大霉素和阿米卡星在不同药物浓度 (0 .5、2、4、8MIC)及不同作用时间 (0、2、4、6、8h)与对照组比较 ,可显著 (P<0 .0 5 )降低大肠杆菌内毒素的释放 ,但这 2种药间相比 ,差异不显著 (P>0 .0 5 )。 相似文献
918.
Gluten free systems lack the viscoelastic network required to resist gas production and expansion during baking. Enzymatic treatments of the GF flours have been proposed initially for creating protein aggregates that mimic gluten functionality but then also for modifying proteins changing their functionality in GF systems. To better exploit the technological function and the potentials of enzymatic processing for improving GF bread quality, it is important to understand the key elements that define the microstructure and baking functionality of GF batters as compared to wheat dough. In this review, some keys are pointed out to explain the different mechanisms that are available for understanding the action of enzymes to effectively design GF viscoelastic matrixes. Focus will be on protein modifying enzymes, because they play a decisive role in the formation of the fine network responsible for improving the expansion of rice batters. 相似文献
919.
920.