微波作用下餐厨垃圾固相中油脂浸出过程研究

餐厨垃圾固相中的油脂易腐化变质,危害环境和人类健康,不利于餐厨垃圾后续资源化处理;而合理回收利用则是一种优良资源。采用微波湿热的方法分离餐厨垃圾固相中油脂,考察了作用时间、温度及微波加热方式对固相中油脂浸出率的影响;利用红外光谱和气质联用分析了微波湿热前后固相中油脂的成分性质。结果表明:餐厨垃圾固相中油脂浸出率随微波作用时间延长呈先增后平稳的趋势,120℃下作用40 min时,浸出率达最高值为72.1%;微波作用下固相中油脂浸出率相比电加热提高了3.1%;微波处理未改变固相中油脂的主要官能团结构,但脂肪酸及其甘油酯含量发生了变化。     

铜对缘管浒苔生理状态的影响

测定了不同条件下Ｃｕ对缘管浒苔可溶性蛋白质含量、膜脂质过氧化水平和藻细胞相对离子外渗率的影响。结果表明，一定浓度的铜离子对海藻具有毒害作用，相应地会引起其可溶性蛋白质含量降低，脂质过氧化水平升高和相对离子外渗率增大。实验结果还证实了ＥＤＴＡ对铜离子毒性的抑制作用和８－羟基喹啉对铜离子毒性的增强作用。     

Toxic effects of 1-methyl-3-octylimidazolium bromide on the wheat seedlings

The toxic effects of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) on wheat seedlings were evaluated. Wheat seedlings were cultivated in aqueous solution with [C8mim]Br at di erent concentrations (0, 1, 2, 4, 6, 8 mg/L). The contents of photosynthetic pigment and proline, peroxidation of membrane lipid, and activities of antioxidation enzymes (superoxide dismutase, catalase, peroxidase and ascorbate peroxidase) in leaves were measured on day 7 after treatment with [C8mim]Br. The results showed that [C8mim]Br significantly decreased the contents of photosynthetic pigments, activities of antioxidant enzymes in the wheat leaves and in dry weight of seedlings, while increased the proline content and membrane lipid peroxidation. The results suggested that [C8mim]Br can inhibit photosynthesis and lead to oxidative stress to wheat seedlings.     

臭氧胁迫对冬小麦光合作用、膜脂过氧化和抗氧化系统的影响

在大田试验的条件下,利用开顶式气室(OTC)研究了臭氧胁迫对冬小麦不同生育期(拔节期、孕穗期、扬花期和灌浆期)光合作用、膜脂过氧化以及抗氧化系统的影响.结果表明,在150nmol·mol-1O3浓度范围内,随着O3浓度的升高和熏气时间的增加,冬小麦叶片总叶绿素、叶绿素a和b含量总体降低,但孕穗和扬花期T1处理组总叶绿素和叶绿素a含量较CK组有所升高;气孔导度(Gs)开放受到影响,单位叶片面积活性降低,胞间CO2浓度(ci)和气孔限制值(Ls)呈波动变化.同时,冬小麦启动了自我保护机制,具体表现为SOD(超氧化物歧化酶)活性先快速升高而后逐渐下降,POD(过氧化物酶)活性呈先下降而后快速升高的变化趋势;从拔节期到扬花期以及从灌浆期1到灌浆期2,CAT(过氧化氢酶)活性表现为先快速升高而后"相对降低",MDA(丙二醛)含量则持续升高;类胡萝卜素含量先升高后下降,单位叶片面积热耗散增加.结果表明,抗氧化酶并不能完全消除冬小麦体内过多的活性氧,造成活性氧积累,进一步加剧了膜脂过氧化作用,导致膜透性增加,叶绿素降解,净光合速率降低,加速冬小麦叶片的老化.     

台湾儿童血清全氟化合物与血脂关联的性别差异研究

目的:全氟辛烷磺酸(PFOS)和全氟辛酸(PFOA)是广泛应用于工业和生活领域的全氟化合物,在人体及环境介质中均可检出。近几年的流行病学研究表明儿童PFOS和PFOA的暴露水平与血脂水平具有相关性。本研究拟进一步研究血清全氟化合物水平与儿童血脂间关联的性别差异。方法:以台湾儿童为研究对象,分析血清中总胆固醇(TC)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、甘油三脂(TG)等生化指标与PFOS和PFOA血清水平的相关性。结果:线性回归模型分析表明男生血清PFOS、PFOA水平与血脂水平具有显著相关性。当男生血清中ln-PFOS和ln-PFOA水平每增加1 ng·m L~(-1)时,TC含量分别增高0.51 mg·d L~(-1)(95%CI:0.30~0.72)和6.53 mg·d L~(-1)(95%CI:1.96~11.11),但在女生中则没有观察到血清PFOS和PFOA水平与TC的相关性。趋势分析结果显示,随着儿童血清中PFOS和PFOA水平的增加,男生和女生血脂的TC、LDL和TG含量呈增高趋势。结论:台湾儿童血清PFOS和PFOA水平与血脂水平存在正相关,且在男生中观察到的效应强于女生。     

栀子黄色素对小鼠血脂代谢的影响

目的 探讨扼子黄色素对高脂膳食小鼠血脂水平的影响.方法 将30只小白鼠随机分为三个组：对照组,高脂模型＋扼子黄色素组、高脂模型＋柠檬黄组（0.2、0.5 mg/g体重）,喂养180 d后,眼球采血测定血清TC、TG、MDA含量.结果 扼子黄色素组血清MDA、TC、TG升高幅度较高脂模型＋柠檬黄组明显减少.结论 扼子黄色素对高脂膳食致血脂升高有阻抑作用.表2,参6.     

Neuroprotective potential of N -acetylcysteine in carbofuran neurotoxicity: A biochemical and histopathological study

The present study was undertaken to evaluate biochemical markers of chronic carbofuran exposure to rats in terms of lipid peroxide and intrasynaptosomal calcium levels and to correlate them with the histopathological changes in brain regions. A significant increase in lipid peroxidation (LPO) in terms of thiobarbituric acid reactive substances (TBARS) was observed in the cerebral cortex (65%) and brain stem (33%) after carbofuran exposure. This was accompanied by a significant increase (87%) in the intracellular free-Ca²⁺ [Ca²⁺]_i levels. N-acetylcysteine (NAC) administration, on the other hand, reversed the carbofuran-induced increase in LPO and [Ca²⁺]_i. Histopathological studies of carbofuran-exposed brain revealed high frequency of pyknotic neurons in the cerebral cortex and microhaemorrhages in the brain stem. NAC supplementation to carbofuran-treated animals resulted in normalisation of the brain architecture as seen by a reduction in the number of pyknotic nuclei in the cerebral cortex. These findings indicate that increased LPO and elevated [Ca²⁺]_i levels are involved in the development of carbofuran neurotoxicity and are eventually responsible for the pathological alterations. The study also demonstrates potential neuroprotective effect of NAC treatment in carbofuran neurotoxicity.     

Alteration of body total antioxidant capacity and thiol molecules in human chronic exposure to aluminum

The physiological role of aluminum (Al) is not yet known. Exposure to Al may cause many human disorders. The aim of this study was to explore how occupational human exposure to Al might affect the body oxidative stress. The relation between Al toxicity and oxidative stress was studied in blood samples obtained from 45 primary Al production workers, with a minimum work history of three years in the age range of 29–52 years. They were evaluated for oxidative stress biomarkers including thiobarbituric acid reactive substances (TBARS) indicator of lipid peroxidation, ferric reducing ability of plasma (FRAP) indicator of total antioxidant capacity, total thiol molecules and Al level in blood. The results showed that workers have significantly higher blood Al levels and concomitant lower blood FRAP and total thiol molecules in comparison to controls. Smokers had lower total thiol molecules than non-smokers. The subjects who had a previous history of disease had lower FRAP levels. It is concluded that Al induces oxidative stress in primary Al production workers. Supplementation of workers with antioxidants may have beneficial effects.     

Inhibition of tetrachloromethane-induced cross-linking of microsomal fatty acids by the spin-trap α-phenyl- N - t -butylnitrone

The effect of the spin-trap α-phenyl-N-t-butylnitrone (PBN) on the formation of fatty acid dimers induced by the anoxic microsomal metabolism of tetrachloromethane was investigated in vitro, in particular, with respect to cross-linking of arachidonic acid with a second one (C₂₀–C₂₀) and of arachidonic acid with docosahexaenoic acid (C₂₀–C₂₂). PBN exerted no effect on anaerobic tetrachloromethane metabolism but inhibited dimer formation, half-maximally at a concentration of 0.1 mmol L^?1. Trichloromethyl octadecenoic acid was also found, but at levels 10-fold lower than the fatty acid dimers. The data suggest that the hepato-protective effect of PBN against tetrachloromethane-toxicity may be due to its ability to scavenge fatty acid radicals, resulting in stable, non-reactive entities, which do not undergo secondary reactions such as cross-linking. The data confirm and extend previous findings that crosslinking plays an important role in tetrachloromethane toxicity and similar cases of metabolic radical-induced toxicity.     

The role of thymoquinone as antioxidant protection on oxidative stress induced by imidacloprid in male and female Swiss albino mice

The aim of the present study was to evaluate the possible protective effects of thymoquinone (TQ), an antioxidant agent, against imidacloprid (IMI)-induced oxidative stress in male and female mice. In total, 48 Swiss Albino male and female mice were fed a standard rodent diet and divided into 3 equal groups: the animals in the control group (vehicle treated) were given corn oil, the second group were orally administered 15 mg/kg/day IMI alone, and the third group were orally administered 15 mg/kg/day IMI and with TQ at 10 mg/kg/day for 21 days. During the experimental period, there were no significant changes between initial body weights and final body weights of IMI treated male and female mice. IMI produced significant increase in blood, liver, kidney, and heart malondialdehyde (MDA) levels and decrease in blood and liver glutathione (GSH) levels. In addition, IMI treatment decreased erythrocyte, liver, and kidney superoxide dismutase (SOD) activity in male mice and decreased erythrocyte and liver SOD activity in female mice. Erythrocyte catalase (CAT) activities were found to be low in male and female mice. However, treatment with TQ reversed IMI-induced oxidative stress, lipid peroxidation, and activities of antioxidant enzymes. Moreover, TQ exhibited protective action against the IMI-induced histopathological changes in tissues of male and female mice. In conclusion, TQ was found to be effective in protecting mice against IMI-induced oxidative stress by enhancing antioxidant defense mechanisms.