首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   57篇
  免费   0篇
林业   17篇
农学   2篇
  6篇
综合类   4篇
农作物   1篇
水产渔业   2篇
畜牧兽医   23篇
植物保护   2篇
  2022年   1篇
  2021年   1篇
  2019年   1篇
  2017年   2篇
  2016年   4篇
  2015年   5篇
  2014年   1篇
  2013年   4篇
  2012年   3篇
  2011年   5篇
  2009年   2篇
  2008年   5篇
  2007年   7篇
  2006年   5篇
  2005年   1篇
  2004年   1篇
  2003年   3篇
  2001年   1篇
  2000年   2篇
  1998年   2篇
  1997年   1篇
排序方式: 共有57条查询结果,搜索用时 15 毫秒
21.
We report an atypical mycobacterial infection in an Indian flap-shelled turtle, Lissemys punctata punctata, that died in an aquarium in Japan. At necropsy, the turtle showed multiple white nodules on the capsular surface and parenchyma of various organs such as the liver, spleen, intestine, and lung. Histologically, granulomatous inflammation surrounding a central zone of necrosis was observed. Sections stained by the Ziehl-Neelsen method revealed numerous acid-fast bacilli in the cytoplasm of macrophages and in the central area of necrosis. The organisms were identified as a mycobacterial species by PCR and nucleotide sequence analysis and revealed 98-100% homology to M. ulcerans. This is, to our knowledge, the first report of mycobacteriosis due to M. ulcerans in a turtle.  相似文献   
22.
Sarcomatous proliferation of spindle cells was present in the mammary gland and many metastatic sites in a 10-year-old female domestic cat with tubulopapillary carcinoma in the mammary gland. Transition from neoplastic tubular structures to spindle cells in the primary site and fascicular proliferation of the spindle cells with or without coexistance of tubulopapillary carcinoma in the primary and metastatic sites were observed. Most of spindle cells were positive for cytokeratin CAM5.2 as well as the normal luminal epithelium but not the myoepithelium. From these results, this case was diagnosed as tubulopapillary carcinoma with spindle cell metaplasia and it was clarified that neoplastic luminal epithelial cells can transform to sarcomatous appearence.  相似文献   
23.
以地被菊花(Dendranthema grandiflomm cv.White Snow)无菌苗叶片为外植体,在附加不同浓度植物生长调节剂的MS基础培养基上诱导培养,通过器官直接发生途径获得再生植株。结果表明,2.0mg/L 6-BA和0.2mg/L NAA组合可获得93.8%的再生芽。将含拟南芥(Arabidopsis thaliana)逆境诱导转录因子DREB1A基因的植物表达载体pBI-DREB1A导入根癌农杆菌(Agrobacterium tumefaciens)LBA4404,农杆菌介导法遗传转化地被菊花White Snow叶盘,经PCR和PCR—Southem检测,DREB1A基因已整合到转化植株的基因组中。遗传转化过程中,预培养2d后,将OD600=0.5~0.7的根癌农杆菌稀释30倍后侵染叶盘10min,再共培养2d,有利于获得最高遗传转化效率。  相似文献   
24.
The efficiency of planting a hybrid larch F1 at two planting densities and of using seedlings of hybrid larch F1 or rooted cuttings of Gream, the registered variety, was investigated. Significantly more time was required to move from one planting spot to the next in plots with 625 seedlings/ha than in plots with 1,333 seedlings/ha, but there was no significant difference between seedlings and rooted cuttings. Approximately 18% more time was needed to plant a single planting stock at the low planting density than at the high density. The need to prune roots or enlarge a planting hole occurred more often for rooted cuttings than for seedlings, and 17% more time was needed to plant rooted cuttings of Gream than seedlings.  相似文献   
25.
26.
27.
Age trends in variance components and heritability were estimated from the spiral grain angle of rings 2–25, as counted from the pith in hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F1. Age-age genetic and phenotypic correlations and the optimum selection age for spiral grain were also calculated. Wood samples were collected from 95 29-year-old trees belonging to 19 full-sib families in a progeny test plantation in Hokkaido, northern Japan. Spiral grain angle data were obtained by the splitting method. Mean grain angles at growth rings used for the analyses were calculated as the arithmetic mean of angles up to respective rings. Generally, the additive genetic variance for mean grain angle decreased with increasing ring number. Although dominance variance was comparatively high near the pith, it decreased to zero in subsequent growth rings. Highest heritability estimates of mean grain angle occurred at ring 4 and then declined with age, ranging from 0.45 down to 0.20. Age-age phenotypic correlations were higher than genetic correlations, especially those involving early growth rings. Optimum selection ages for spiral grain based on genetic and phenotypic correlations were estimated as 3 and 4 years (cambial age), respectively, in which maximum gain efficiency per year were obtained.  相似文献   
28.
The tangential strain on the inner bark surface of Fagus crenata sapling stems was continuously measured using strain gauges. The total strain increased daily, increasing at night and decreasing during the day. When tension wood was induced by artificial inclination, the strain increased more on the upper side than on the lower side; and the increment in the strain at night was larger on the upper side than on the lower. The change in tangential strain on the inner bark surface arose from changes in the water content and the volume of differentiating cells. Differentiating tension wood fibers appear to contain more water and to expand more at night than differentiating normal wood fibers. We can determine whether tension wood is formed from the tangential strain during growth.  相似文献   
29.
30.
Simultaneous removal of bilateral thyroid tumors was performed while preserving the parathyroid gland in six dogs. At least one external parathyroid gland was identified in all dogs. In five cases, the external parathyroid gland and its blood supply were preserved intact. In one dog, the vessels supplying the external parathyroid gland had been invaded by the tumor, and the gland was thus removed and reimplanted into the sternohyoid muscle. That dog required postoperative treatment with oral calcium gluconate and vitamin D3. Local tumor recurrence was not observed in any of the cases. The mean survival time was 920 days. We found that the external parathyroid gland could be identified and preserved in most dogs undergoing total thyroidectomy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号