增加城市绿量的好方法--垂直绿化

垂直绿化做为一种立体绿化形式,占地少,绿化效果好,是增加城市绿量和形成城市美好景观的好方法.本文从垂直绿化的特点、垂直绿化的材料、垂直绿化的形式三方面详尽阐述了在城市中发展垂直绿化的必要性.     

β‐Carotene is incorporated or mobilized along with triglycerides in bovine adipose tissue in response to insulin or epinephrine

Pasture fed cattle ingest substantial amounts of β‐carotene (β‐C). Not all of the carotenoid compound is transformed into vitamin A, but the surplus is deposited in adipose tissue (AT). The mechanisms of β‐C incorporation and mobilization are unknown. Two experiments were conducted using explants from bovine AT cultured in vitro. First, β‐C incorporation by explants from three animals was examined with different β‐C concentrations (0, 1, 5 and 20 μm ) and different times of incubation (every 5 h up to 25 h). The data showed a significant increase of β‐C concentration in explants only for 20 μm β‐C. Secondly, effects of insulin and epinephrine on β‐C and triglyceride (TG) contents of explants were studied. Explants from six animals were incubated with either hormone and 0 or 20 μm β‐C for 20 h. Both TG and β‐C contents were affected positively by insulin and negatively by epinephrine. Interestingly, changes in ratios of β‐C/TG (hormone vs. control) were similar (1.7 × 10^?3 and 1.8 × 10^?3), respectively, for insulin and epinephrine, indicating that β‐C level is directly related to TG content. We also report the presence of mRNA for β‐C 15, 15′ oxygenase in bovine AT. The in vitro culture system using explants from bovine AT is a promising model to investigate factors that might affect the accumulation and metabolism of β‐C.     

珍稀植物北碚榕的种子萌发及繁殖研究

以北碚榕种子为材料,研究酸蚀与浸种时间、萌发基质与温度、光照条件和赤霉素处理对种子萌发的影响,通过育苗将幼苗移栽到田间.结果表明,北碚榕种子经酸蚀处理后可以萌发.适宜的酸蚀时间为3~5min,浸种时间为4~8h(30℃),萌发基质为河沙,萌发温度为(25±1)℃(3 000lx每天光照12h).在此条件下,15d发芽率可达90%以上.每天光照24h和300~400mg/L赤霉素(GA3)浸种能显著提高发芽率.幼苗在培养皿蛭石中成苗率达85%以上,在穴盆营养土中和营养钵沙壤土中成活率均达95%以上,田间移栽成活率达100%,生长正常.解决了北碚榕的种子萌发问题,初步获得了育苗技术,为北碚榕的种子繁殖奠定了基础.     

鸡新城疫Ⅰ系疫苗株Vero细胞培养物的免疫试验及Vero细胞的致瘤性检查

对鸡新城疫Ⅰ系毒 Ｖｅｒｏ 细胞培养物进行了安全性及免疫试验。结果表明, Ⅰ系毒 Ｖｅｒｏ 细胞培养物对２月龄鸡是安全的。免疫试验结果表明, Ⅰ系毒 Ｖｅｒｏ 细胞培养物与鸡胚毒一样, 具有良好的免疫原性, 免疫２ 月龄鸡４ 个月后, Ｈ Ｉ抗体还在６ｌｏｇ２ 以上, 免疫成年鸡１３ 个月后, Ｈ Ｉ抗体还高达５５ｌｏｇ２ 。试验还证明, Ｖｅｒｏ 细胞对鸡没有致瘤性, 安全可靠, 可以用于鸡新城疫疫苗的生产。     

Hepatogenous photosensitization associated with liver copper accumulation in buffalos

Four 1.5-year-old, male, Murrah buffalos were maintained during eight months without direct solar exposure during a study of copper toxicosis. Four days after solar exposure, all buffalos presented clinical manifestations consistent with acute photosensitization, including anorexia, apathy, loss of body weight, and generalized cutaneous lesions. Gross lesions were characterized by severe erythema, localized edema, fissures, tissue necrosis, gangrene and crust formation with serous exudation. Liver copper concentration was evaluated, and cutaneous biopsies were taken when clinical signs were evident. The liver copper concentration before solar exposure was increased in all animals. Histopathologic examination of the skin revealed hepatogenous photosensitization characterized by parakeratotic hyperkeratosis, acantholysis, degeneration of squamous epithelial cells, epidermal necrosis with atrophy of sweat glands, and multifocal superficial and deep dermal edema. These findings suggest that asymptomatic accumulation of copper within the liver might have induced hepatic insufficiency thereby resulting in secondary photosensitization when these buffalos were exposed to sunlight.