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41.
日本血吸虫非叉型尾蚴感染动物试验   总被引:2,自引:1,他引:1  
试验采集云南巍山地区自然条件下的钉螺,压碎钉螺、检获尾蚴,发现为非叉型尾蚴。将非叉型尾蚴400~850条/只经皮肤感染家兔,同时,用云南洱源的叉型尾蚴作对照试验。感染后50~55 d解剖兔子,试验组检获到日本血吸虫,荷虫量为10~15条/只。试验结果表明,云南巍山非叉型尾蚴能感染动物,该试验结果为丰富日本血吸虫的生活史提供了极有价值的补充。  相似文献   
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生态型农业观光园规划设计   总被引:1,自引:0,他引:1  
通过阐述园区规划设计原则及理论根据,结合实例分析了生态型农业观光园的设计内容,有利于更好的研究与开发农业观光园项目。  相似文献   
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在广泛收集乌冈栎地理分布资料的基础上,利用目前常用的植被与气候相互关系的研究方法,结合温暖指数(WI)、寒冷指数(CI)、干燥度指数(K)、水热综合指数(S)、年均生物温度(BT)、可蒸散量(PET)和年均可能蒸发量率(PER),以及单一的气象因子一月均温(TM-Jan)、七月均温(TM-Jul)、最高温(TMax)、最低温(TMin)、年均温(TM-A)、年均降水量(PM)等,对乌冈栎在东亚地区的地理分布及其与气候的关系进行了研究。结果表明:乌冈栎在中国地理分布在23°-34°N、100°-120°E,日本分布在26°-37°N、128°-140°E,均属于亚热带分布。气候环境指数研究的结果表明乌冈栎各项指数平均值均较低,与亚热带分布的青冈的指数接近,因此其性质为亚热带耐寒树种。通过热量曲线的比较,反映了中日两国乌冈栎分布范围的差异。结合主成分分析可知,影响乌冈栎分布的最主要因素是温度,并将其分布区划分为5类,包括:日本区(A)、中国华东区(B)中国西南部区(C)、中国西北部区(D)和中国南部区(E)。最后建立了乌冈栎生物地理模型,对预测该物种的分布提供了科学参考依据。  相似文献   
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The reason why cows carrying the mutation of complex vertebral malformation (CVM) show poor reproductive capability although they carry only one mutant allele is still not fully understood. Monitoring the progesterone profiles during oestrous cycle and early pregnancy in carrier cows might help explain their lowered reproductive capability. Progesterone concentration was measured in 19 CVM carrier cows and 21 control cows during oestrous cycle and early pregnancy. Milk samples were collected from all cows starting on the day of artificial insemination until day 45 post‐AI. Progesterone was measured in skim milk using enzyme‐linked immunosorbent assay (ELISA). Progesterone concentration was significantly reduced on day 7 (p < 0.05) and day 9 (p < 0.01) post‐insemination in conceived CVM carrier cows when compared with that in control conceived cows. The mean progesterone concentration during early pregnancy was significantly lower (p < 0.05) in conceived cows with CVM than that of control cows in the same period. However, the mean progesterone concentration did not differ significantly (p = 0.072) in CVM cows that showed fertilization failure or embryonic death than that of control cows. Additionally, of 13 conceived control cows, eight cows (61.5%) showed normal luteal function. In contrast, of nine conceived CVM cows, only four cows (44.4%) showed normal luteal function. The conception rate was 47.4% in CVM carrier cows and 61.9% in control cows, but this difference did not reach significance. In conclusion, progesterone concentration might be lowered during early pregnancy in conceived CVM cows compared with that in control cows.  相似文献   
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 【目的】青花菜的抗癌功能主要与4-甲基亚磺酰丁基硫苷的降解产物萝卜硫素有关,通过测定不同青花菜材料花球、茎和叶片中两者的含量并分析两者含量间的相关性,为青花菜高营养品质育种提供理论依据。【方法】采用反相高效液相色谱法,对24个不同青花菜材料花球、茎和叶片中4-甲基亚磺酰丁基硫苷含量,及其中的10份材料花球、茎和叶片中萝卜硫素含量进行测定和分析。【结果】青花菜不同基因型间以及不同器官间4-甲基亚磺酰丁基硫苷和萝卜硫素含量差异均极显著,4-甲基亚磺酰丁基硫苷和萝卜硫素含量均为花球含量最高,其次为茎,叶片含量最低;不同材料花球中4-甲基亚磺酰丁基硫苷平均含量分别为茎和叶片的4.4和13.97倍,萝卜硫素平均含量分别为茎和叶片的4和8.7倍,而有的基因型材料茎和叶片中4-甲基亚磺酰丁基硫苷的含量较高,约为花球中的50%;参试的10个不同基因型材料的花球、茎和叶片中的萝卜硫素含量与其前体4-甲基亚磺酰丁基硫苷含量间相关系数分别为0.9886**,0.9994**,0.9935**。【结论】不同青花菜材料间不同器官中4-甲基亚磺酰丁基硫苷含量存在显著差异;在青花菜萝卜硫素开发应用中,可选择其前体4-甲基亚磺酰丁基硫苷作为筛选指标,并可筛选茎和叶中4-甲基亚磺酰丁基硫苷含量较高的材料作为提取萝卜硫素的原料。  相似文献   
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The objectives of the present study were to investigate the relationship between the morphological status of cumulus cells surrounding canine oocytes after maturation culture and the meiotic stage of the oocytes. In addition, the effect of the removal of cumulus cells from canine cumulus-oocyte complexes (COCs) during maturation culture on their meiotic competence was examined. Canine COCs were collected from bitches at the anoestrous and dioestrous stages and only COCs with >110 microm in vitelline diameter were cultured in medium 199 with 10% canine serum for 72 h. In the first experiment, the relation between the morphological status of cumulus cells surrounding oocytes cultured for 72 h and their meiotic stages was examined. At the end of maturation culture, the proportions of intact, partially nude and completely nude oocytes were 65.2%, 22.9% and 11.9%, respectively. The proportion of maturation to metaphase II of completely nude oocytes was highest among the oocytes with different morphological status of cumulus cells. In the second experiment, the cumulus cells were partially or completely removed from COCs at 48 h after the start of maturation culture and the oocytes were cultured for a further 24 h. The proportion of oocytes reaching metaphase II in the completely denuded oocytes was significantly higher than that in the control oocytes without the removal treatment of cumulus cells. The results indicate that morphological status of cumulus cells surrounding oocytes may be related to the nuclear maturation of canine oocytes, and the removal of cumulus cells from COCs during maturation culture can promote the completion of oocyte meiotic maturation.  相似文献   
50.
Mammalian sperm undergo a series of biochemical transformations in the female reproductive tract that are collectively known as capacitation. Cyclodextrins added to the sperm culture medium have been described to induce in vitro sperm capacitation, enabling its use in protein‐free media. However, the additive capacitating effect of methyl‐β‐cyclodextrin (MβCD) in the medium containing bovine serum albumin (BSA) is unknown in the bovine species. In this study, we evaluated the effects of incubating frozen–thawed bovine spermatozoa in a BSA‐containing medium supplemented with MβCD on different sperm quality and functional parameters. Sperm viability decreased with the addition of MβCD in a dose‐dependent manner (p < 0.05), and DNA damage could be observed but only with the highest concentration of MβCD. However, pre‐incubation of spermatozoa in MβCD‐supplemented medium improved the capacitation status as assessed by the increase in plasma membrane fluidity, intracellular calcium concentration, induced acrosome reactivity and zona pellucida (ZP)‐binding ability (p < 0.05). Thus, we conclude that MβCD supplementation is able to enhance the capacitation status of frozen–thawed bovine spermatozoa cultured in capacitation medium containing BSA and could result in a valid strategy for its application on artificial reproductive technologies such as in vitro fertilization or intracytoplasmic sperm injection.  相似文献   
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