Vitamin E reversal of the effect of extracellular calcium on chemically induced toxicity in hepatocytes

Isolated rat hepatocytes were incubated in the presence or absence of extracellular calcium and alpha-tocopherol succinate with three different toxic chemicals; namely, adriamycin in combination with 1,3-bis(2-chloroethyl)-1-nitrosourea, ethyl methanesulfonate, and the calcium ionophore A23187. In the absence of extracellular calcium these three compounds were far more toxic to the cells than in its presence. The addition of vitamin E to calcium-free medium, however, protected hepatocytes against toxic injury, whereas cells incubated in medium containing calcium were not protected. Hepatocyte viability during each toxic insult correlated well with the cellular alpha-tocopherol content but not with the presence or absence of extracellular calcium. These results suggest that cellular alpha-tocopherol maintains the viability of the cell during a toxic insult and that the presence or absence of vitamin E in the incubation medium probably explains the conflicting reports on the role of extracellular calcium in toxic cell death.     

Lipoperoxidation of lung lipids in rats exposed to nitrogen dioxide

Absorption spectra characteristic of diene conjugation and typical for peroxidized polyenoic fatty acids can be induced in rat lung lipids after the rats have been exposed to a scant amount of nitrogen dioxide (1 part per million) for 4 hours. The peroxidative changes do not occur immediately but appear to reach a maximum between 24 and 48 hours after exposure. The prooxidant effect of this atmospheric pollutant in rat lung lipids may be partially prevented by prior treatment of the animal with large doses of alpha-tocopherol.     

Vitamin E oxidation with alkaline ferricyanide

Oxidation of dl-alpha-tocopherol or its model, 6-hydroxy-2,2,5,7,8-pentamethylchroman, with alkaline ferricyanide yields a variety of products. In addition to the known dimeric keto ether, two new products, compound A, a trimer, and compound B, an isomer of compound A, were ioslated. Ultraviolet and infrared absorption spectra and paper chromatography indicate that compound A might be identical with liver metabolite "O" which results from the addition of alpha-tocopherol to the diet.     

油茶籽成熟过程中功能成分的变化规律

研究了福建省优良无性系油茶品种"闽48"在成熟过程中油茶籽功能成分的变化规律。结果表明:在成熟过程中油茶籽的含油量逐渐增加;必需脂肪酸的相对含量呈下降趋势;角鲨烯的含量先增加后减少,最大时含量达到306.6μg.g-1;油茶籽中的维生素E主要为α-生育酚,在成熟过程中,α-生育酚的含量先缓慢增加后迅速增加,增加到最大值后开始逐渐减少。     

添加剂在猪精液冷冻保存中的应用

猪精液的冷冻保存显著影响猪精子的运动学参数,损伤精子质膜、顶体和DNA完整性,降低解冻后精子活率和受精能力.近年来,在以甘油和蛋黄作为冷冻保护剂的基础上,为了有效降低冷冻-解冻对精子的损伤,提高解冻精液的受精能力,研究人员将OEP、抗氧化剂(甲基黄嘌呤、丁羟基甲苯、谷胱甘肽、超氧化物歧化酶、过氧化氢酶、褪黑素和维生素E等)、2-羟丙基β环糊精以及透明质酸等物质作为添加剂应用于猪精液的冷冻保存,结果表明这些物质在保护精子质膜和顶体完整性,提高解冻后精子活力、活率和受精能力等方面均有显著作用.     

Bilirubin is an antioxidant of possible physiological importance

Bilirubin, the end product of heme catabolism in mammals, is generally regarded as a potentially cytotoxic, lipid-soluble waste product that needs to be excreted. However, it is here that bilirubin, at micromolar concentrations in vitro, efficiently scavenges peroxyl radicals generated chemically in either homogeneous solution or multilamellar liposomes. The antioxidant activity of bilirubin increases as the experimental concentration of oxygen is decreased from 20% (that of normal air) to 2% (physiologically relevant concentration). Furthermore, under 2% oxygen, in liposomes, bilirubin suppresses the oxidation more than alpha-tocopherol, which is regarded as the best antioxidant of lipid peroxidation. The data support the idea of a "beneficial" role for bilirubin as a physiological, chain-breaking antioxidant.     

用快速干灰法处理样品测定奶粉中金属元素的含量

本文叙述用快速干灰法处理样品测定奶粉中金属元素的含量,并与常规的干法和湿法处理进行对比试验,用三种方法进行的回收试验和精密度试验所得结果,经统计分析表明,快干法测定的结果准确可靠,准确度、精密度以快速干灰法为最好。     

Role of Na+/H+ exchange by interferon-gamma in enhanced expression of JE and I-A beta genes

The rapid transductional sequences initiated by interferon-gamma (IFN-gamma) on binding to its receptor regulate functional and genomic responses in many cells but are not well defined. Induction of macrophage activation is an example of such functional and genomic changes in response to IFN-gamma. Addition of IFN-gamma to murine macrophages, at activating concentrations, produced rapid (within 60 seconds) alkalinization of the cytosol and a concomitant, rapid influx of 22Na+. Amiloride inhibited the ion fluxes and the accumulation of specific messenger RNA for two genes induced by IFN-gamma (the early gene JE and the beta chain of the class II major histocompatibility complex gene I-A). The data indicate that IFN-gamma initiates rapid exchange of Na+ and H+ by means of the Na+/H+ antiporter and that these amiloride-sensitive ion fluxes are important to some of the genomic effects of IFN-gamma.     

冷却方式对宰后分割牛肉肉用品质的影响

[目的]研究不同冷却方式对宰后分割牛肉品质的影响,为改善牛肉嫩度,增强食用品质提供理论依据。[方法]以宰后分割牛肉为材料,用快速冷却、常规冷却、延迟冷却3种冷却方式对宰后分割牛肉进行处理,于4℃冷库成熟7 d,考察各冷却方式对牛肉品质的影响。[结果]经快速冷却处理的分割牛肉由于降温速度快,2 h温度降至4℃左右时,p H高于6.2,出现肌肉冷收缩现象,剪切力最大,在成熟过程中嫩化效果不佳(P0.05),且对肉色影响不大。常规冷却的牛肉降温速率仍较快,且冷却失重较大。延迟冷却后的牛肉因温度较高,可以促进牛肉进入僵直期,随着成熟的进行牛肉的嫩度不断增大,亮度和红度得到改善,虽然冷却损失较快速冷却的牛肉大,但牛肉的嫩度改善程度最大,牛肉的食用品质最佳。[结论]延迟冷却很大程度上改善了牛肉嫩度,增强了牛肉食用品质。     

砂生槐单粒种子DNA的快速提取及RAPD检测

为探讨快速提取种子DNA的有效方法,以砂生槐单粒种子为试验材料,在传统CTAB法基础上建立一种快速提取DNA的方法,并通过紫外分光光度法、凝胶电泳和RAPD-PCR检测所提基因组DNA。结果表明:快速法提取得到了质量较好、浓度及纯度较高的DNA,可以满足分子生物学实验的要求。此方法操作方便、快捷,是一种有效的砂生槐种子的DNA提取方法。     

快速笼式烟夹减工降本提质增效作用研究

[目的]验证快速笼式烟夹在烤烟烘烤上减工降本提质增效方面的作用。[方法]以采用挂竿装烟和常规三段式烘烤工艺进行烘烤作为对照,用快速笼式烟夹装烟,分别采用2种三段式烘烤工艺烘烤为处理,研究使用快速笼式烟夹烘烤的配套烘烤工艺与烟叶质量。[结果]使用笼式烟夹装烟量比常规挂杆多50%以上,极大提高了烤房的烘烤能力,同时减工增效显著;笼式烟夹高湿变黄三段式烘烤工艺处理烟叶样品外观质量、化学成分和感官质量整体比普通挂竿较好。[结论]快速笼式烟夹在烤烟专业化烘烤和散叶分级收购方面具有很好的应用前景。     

The aerodynamics of free-flight maneuvers in Drosophila

Using three-dimensional infrared high-speed video, we captured the wing and body kinematics of free-flying fruit flies as they performed rapid flight maneuvers. We then "replayed" the wing kinematics on a dynamically scaled robotic model to measure the aerodynamic forces produced by the wings. The results show that a fly generates rapid turns with surprisingly subtle modifications in wing motion, which nonetheless generate sufficient torque for the fly to rotate its body through each turn. The magnitude and time course of the torque and body motion during rapid turns indicate that inertia, not friction, dominates the flight dynamics of insects.     

猪细小病毒LAMP检测方法的建立

 【目的】建立一种快速、敏感、特异的检测猪细小病毒(PPV)环介导等温扩增(LAMP)方法,为诊断猪细小病毒提供准确可靠工具。【方法】根据GenBank公布的PPV序列,在其保守序列区域设计了多套LAMP引物,利用LAMP Real Time Turbidimeter LA-320仪监测反应进程并筛选最佳引物、反应条件,建立了对PPV病毒DNA进行特异扩增的 LAMP检测方法,并可通过加入SYBR Green I肉眼判断结果。【结果】该方法在63℃恒温下作用45 min,PPV病毒DNA获得了高效率的特异性扩增;其检出限量为0.23 TCID50,敏感性高;在反应结束后加入SYBR Green I肉眼判断结果,与Real Time Turbidimeter LA-320仪监测结果一致。通过对20份临床样品的LAMP检测与免疫荧光鉴定、PCR方法比对,符合率均为20/20。【结论】本研究建立的PPV LAMP检测方法具有快速、特异、灵敏,操作简单、设备要求低的特点,适合用于临床PPV快速检测。     

Bacteria-phage antagonistic coevolution in soil

Bacteria and their viruses (phages) undergo rapid coevolution in test tubes, but the relevance to natural environments is unclear. By using a "mark-recapture" approach, we showed rapid coevolution of bacteria and phages in a soil community. Unlike coevolution in vitro, which is characterized by increases in infectivity and resistance through time (arms race dynamics), coevolution in soil resulted in hosts more resistant to their contemporary than past and future parasites (fluctuating selection dynamics). Fluctuating selection dynamics, which can potentially continue indefinitely, can be explained by fitness costs constraining the evolution of high levels of resistance in soil. These results suggest that rapid coevolution between bacteria and phage is likely to play a key role in structuring natural microbial communities.     

成都白鸡快、慢羽纯系的选育及羽型研究

1982年我室就成都白鸡羽型,快,慢羽纯系的选育、K(慢)、k(快)基因频率及杂种鸡羽速自别雌雄的准确率等进行了研究。按主翼羽和覆主翼羽生长状况,该鸡种初生雏羽型分为:快羽一型,慢羽三型。K(慢),k(快)基因频率分别为0.1602和0.8398。表型鸡经测交,纯繁选育出成都白鸡快,慢羽两个品系。以成都白鸡慢羽母鸡同快羽京白公鸡杂交,其杂种鸡羽速自别雌雄的准确率为99.13%。     

脂肪酶和酯酶指纹分析在嗜酸耐热菌快速鉴定中的应用

【目的】采用反相高效液相色谱建立嗜酸耐热菌的脂肪酶和酯酶指纹图谱,为建立基于脂肪酶和酯酶指纹分析的嗜酸耐热菌快速鉴定方法提供参考。【方法】将5个脂肪酶和酯酶底物直接与嗜酸耐热菌反应,通过反相高效液相色谱检测得到了9株嗜酸耐热菌的脂肪酶和酯酶指纹色谱图,并对色谱数据进行系统聚类分析。【结果】所得脂肪酶和酯酶指纹图谱能将脂环酸芽孢杆菌和芽孢杆菌明显分为2个类群,且同一属的2个不同种的细菌也能得到正确归类。【结论】脂肪酶和酯酶指纹分析能够用于嗜酸耐热菌的快速鉴别,且简便快速、重现性好、经济成本低,具有广阔的应用前景。     

伊犁地区绵羊李氏杆菌药敏特性及平板凝集快速诊断方法的建立

[目的]建立一种快速检测李氏杆菌病的方法。[方法]通过对实验室保存的5株李氏杆菌分离株进行药敏试验,用甲醛灭活苗免疫试验动物,制备特异性抗体,将特异性抗体与抗原进行平板凝集试验。[结果]分离菌株对氨苄西林、庆大霉素、链霉素高度敏感,对头孢唑啉、左氧氟沙星和多粘菌素中度敏感,对头孢他啶、头孢呋辛钠耐药性较强。通过用甲醛灭活苗免疫试验动物来制备特异性抗体,将特异性抗体与抗原做平板凝集试验,建立一种快速准确检测李氏杆菌病的方法。[结论]成功建立了一种快速检测李氏杆菌病的方法。     

土壤速效养分速测方法研究

为探索适合在基层推广使用的土壤养分速测方法,采用3种速测方法和常规分析法对10种不同类型的土壤样品的铵态氮、硝态氮、速效磷、速效钾、pH进行测定.结果表明:YN-2 000速测仪测定结果能够反映测定样品的养分含量及变化情况.在3种速测方法中,YN-2 000速测仪的测定结果变异系数较小,可在测土配方施肥中推广应用.     

Study on the rapid propagation of Phalaenopsis hybrid

This paper studied the rapid propagation technology of Phalaenopsis hybrid by using the peduncle buds as the explants, and screened out a kind of culture medium, which was simple, rapid, available and high rate of propagation.     

Rapid light-induced decrease in pineal serotonin N-acetyltransferase activity

Light acting by way of the eye causes the dark-induced activity of serotonin N-acetyltransferase in the pineal gland of the rat to decrease with a halving time of about 3 minutes. This effect, which is one of the more rapid physiological changes known to occur in the activity of any enzyme that metabolizes biogenic amines, appears to explain the rapid increase in the concentration of pineal serotonin that is caused by light exposure at night.