日光温室嫁接番茄生长特性及抗病性研究

近年来，由于设施蔬菜生产的高复加值，使得连作障碍严重，土传病害广泛蔓延。有关嫁接栽培早结果、丰产、增强植株抗性等报道较多。但嫁接对番茄生长特性及抗病性影响的研究报道较少。本试验旨在选择早产、高产、抗病性砧木，为设施蔬菜无公害生产提供科学的理论依据和指导方向。     

重庆地区色叶植物资源及其在园林中的应用

色叶植物是未来园林应用的主要造景植物之一，本文就重庆地区色叶植物资源作了详细调查．按植物色彩分成常色叶类、春色叶类、秋色叶类和两季色类，并对其在园林中的应用途径和前景作了详尽介绍．     

不同贮藏温度对大五星枇杷果实保鲜效果的研究

枇杷成熟于初夏高温多湿季节，果实生理活动旺盛，含水量多，极易腐烂变质，一般条件下难以贮存和长途运销，采后损失率高。目前，枇杷贮藏最常用的方法是冷藏法。郑永华等把枇杷果实在1℃低温贮藏，可显著抑制果实失水，贮藏期可达20天以上；Mukerjece认为，枇杷贮藏在3℃低温下能减少腐烂；周德荣通过0、5、15℃和常温比较表明，“照种”枇杷在5℃下贮藏31天的好果率最高为83．9％。但近年来，一些研究报道，枇杷果实在不适宜的低温下长期贮藏会发生冷害现象。曾雅鹃等发现，在1℃低温下贮藏，枇杷果皮难剥，果肉变硬，     

浅谈蛋鸡开产体重对生产性能的影响

1、产蛋高峰短而低的问题。当养殖户遇到产蛋高峰不高或高峰上去后，又很快下降的问题时，往往将问题归咎到种鸡或饲料上，其实除了上面的问题外，还有一个重要的问题被忽视，这就是开产前的体重问题。根据国外各个品种的饲养要求，正常的鸡群在6周龄平均体重应达到标准上限或超标10％，均匀度达到90％以上；12周龄平均体重达标即可，均匀度应在85％以上；18周龄平均体重应达标或超标，均匀度达到80％以上。     

一种利用制冷机产生的副热生产热水的技术

为了保持牛奶的新鲜程度,防止牛奶变酸和细菌数升高,各个规模牛场和收奶站均配备了牛奶冷却设备,同时还需要通过锅炉或电加热等方式生产大量的热水来清洗设备。利用锅炉或电加热生产热水不但浪费了大量的财力、物力和人力,还造成了环境污染。现介绍一种不额外消耗能源解决热水供应的方法,供大家参考。1原理冷冻机在制冷的同时,产生大于制冷量的热量。压缩机高压出来的温度一般超过90℃以上,这部分热量一般经过风冷的方式通过散热器散发到室外。特别是夏天,气温较高,散热器散热效率较低,需要浪费大量的冷却水冷却,即使这样,有时温度还是降不…     

Comparison of morphology, viability, and function between blood and milk neutrophils from peak lactating goats

The morphological features of blood and milk neutrophils from peak lactating goats were compared using light microscopy, scanning electron microscopy and flow cytometry in order to investigate the cytological changes of neutrophils after migration into the mammary gland. The kinetics of reactive oxygen intermediates (ROI) generation and gelatinase release of blood and milk neutrophils, with or without stimulation of phorbol 12-myristate, 13-acetate ester (PMA), were used to characterize their responses to inflammatory stimuli. Neutrophils isolated from goat milk were highly segmented and contained multi-lobed nuclei. Ultrastructurally, milk neutrophils were more ruffled on the surface compared to blood neutrophils. Approximately 30% of milk neutrophils were undergoing cell death, either necrosis or apoptosis, in contrast to 8% of blood neutrophils. The ROI production of activated milk neutrophils peaked earlier than blood neutrophils, but the duration and the intensity were much less. Neutrophils from both sources augmented the release of gelatinase in response to PMA (1 ng/mL). However, the amount of gelatinase released from milk neutrophils was lower (P < 0.05) than that of blood neutrophils. In summary, more neutrophils become apoptotic and necrotic in the mammary gland, presumably due to spontaneous aging, the process of diapedesis, and the interaction with milk components. Milk neutrophils have impaired functionalities in comparison with blood neutrophils. The information is relevant when studying mammary gland immunity and related diseases, such as mastitis.     

Culture of Differentiated Adult Rabbit Auricular Chondrocytes

Chondrocytes dedifferentiate to a fibroblast‐like phenotype on plastic surfaces. Dedifferentiation is reversible if these cells are then cultured embedded in gels as alginate, agarose or collagen. Chondrocytes cultured in suspension on a non‐adherent surface are also known to form aggregates of differentiated cells. The knowledge of chondrocyte behavior in culture is relevant for tissue engineering purposes. In this report we describe a simple method to culture differentiated or redifferentiated rabbit auricular chondrocytes on plastic surfaces with a stable phenotype. When chondrocyte aggregates formed in suspension are next seeded on plastic surfaces, most of them attach to the plastic as round or polygonal cells, and this morphological differentiation, confirmed by the presence of type II collagen, is stable for long culture periods. We also report that the addition of aggregates to monolayer cultures of dedifferentiated chondrocytes results in their redifferentiation, as is shown by their morphological changes and the synthesis of type II collagen. Therefore, this simple method can be useful for the study of chondrocyte behavior on plastic surfaces and for redifferentiating previously proliferated chondrocytes in tissue engineering techniques. Furthermore, these results demonstrate that, in addition to culture conditions such as cell isolation method or cell‐density, chondrocyte behavior on plastic depends on the presence or absence of aggregates resulting from the dissociation process.     

Effect of Liucha extract on tumor K562 cell growth

AIM:To investigate the effects of Liucha extract on the growth of tumor cells in vitro and its possible mechanism.METHODS:The capability of colony forming of human leukemia K562 cell in vitro and the cells metabolism were studied by semi-solid agar culture and MTT staining. Then , the changes in morphology in the tumor cells were examined using electronic microscope.RESULTS:Semi-solid agar culture and MTT colorimetric analysis showed that Liucha extrats could significantly inhibit the growth of the tumor cells and their capability of colony forming. Also,under the electronic microscope,it was found that the tumor K562 cell had a narrower perinuclear space,condensation of chromatin and an enlarged mitochondria , in which the cristase disappeared.CONCLUSION:The extract from Liucha possesses an inhibitory effect on K562 cell growth in vitro through affecting the metabolism of the tumor cells.     

陕甘宁老区脆弱生态环境定量评价——以榆林、延安两市为例

位于黄土高原中部的陕甘宁老区生态环境极为脆弱 ,近年来由于气候、人类开发资源等自然和人为原因 ,使生态环境的脆弱程度升高。选定年降水量、年均温、蒸发量等 8个指标 ,定量评价各县 1 970 - 2 0 0 0年的脆弱度状况 ,结果表明榆林、延安两市生态环境整体脆弱 ,脆弱度存在空间差异但差异不明显 ,时间段上的波动幅度不大。陕甘宁老区脆弱生态环境具有不稳定性 ,对外界干扰较敏感。     

不同粘度矿物油助剂对除草剂活性的影响

室内及温室内测定了10种不同粘度矿物油助剂对除草剂防除苘麻和稗草药效的影响及对玉米苗期的安全性。结果表明,10种矿物油助剂均不同程度地增加了氰草津和烟嘧磺隆防除两种杂草的活性。其中粘度为46 mm2/s (40℃)的矿物油乳剂(MOC46)对供试除草剂药效的增强作用最为明显,其次为粘度32 mm2/s (40℃)的矿物油乳剂。10种助剂对氰草津药效的增强作用大于对烟嘧磺隆。MOC46对除草剂活性的增加由高到低依次为:莠去津、氰草津＞莠去津+氰草津、莠去津+烟嘧磺隆、氰草津+烟嘧磺隆＞烟嘧磺隆;对玉米苗期安全性依次为:莠去津、烟嘧磺隆、莠去津+烟嘧磺隆＞莠去津+氰草津、氰草津+烟嘧磺隆＞氰草津。氰草津与MOC46混用对玉米苗期药害较重。