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排序方式: 共有103条查询结果,搜索用时 15 毫秒
91.
U Schnurrbusch G Otto T Hong E Ullrich K Elze 《Archiv fuer experimentelle veterinaermedizin》1990,44(5):703-716
Optical light microscopy was used in investigations of ovariectomised gravid gilts to which progesterone doses between 120 mg and 40 mg as well as 250 micrograms of oestradiol benzoate had been daily applied to preserve gravidity, with 12 mg of norgestrel being additionally administered to some of them. These investigations were conducted for the purpose of studying locally delimited effects of conception on the placental structure. Uterus tissue was sampled from living and dead embryos (centre and sides of ampullae) as well as from uterus regions free of foetal membranes (in-between ampullae). With adequate progesterone supply, embryos were shown to clearly affect the endometrial structures. Endometrium in the centre of ampullae, with living embryos, was lower than at points without embryos. Surface epithelium was flattened, and endometrial stroma was more strongly oedematised. Strongly pronounced hyperaemia occurred to subepithelial stroma in the centre of ampullae, and uterine glandular function was unambiguously stimulated. These embryo-triggered effects were much less or no longer detectable at all under conditions of inadequate progesterone supply (40 mg/die). Administration of 12 mg of norgestrel, in addition to 40 mg/die of progesterone, enabled embryos to exercise gravidity-specific influence upon the endometrium, as in cases of sufficient progesterone supply. 相似文献
92.
In 2004 in the village Neukirchen/Inn the introduction of the invasive longicorn beetle Anoplophora glabripennis to Bavaria was detected. A maple tree near to a truckage company dealing with granite stones from Asia showed less foliation. Two larvae were found in a branch and to confirm the supposition the larvae were sent to the Federal Forest Research Centre in Vienna for a DNA-analysis. After the unambiguous identification of A. glabripennis a safety zone was established around the centre of the infestation. Monitorings for damaged deciduous trees which were assumed to be host plants were carried out. The citizens of the affected area were informed about the invasive species and a general ordinance was published committing the inhabitants for assistance in eradication measures. 16 trees have been cut down, chaffed and burned during the season 2004: five maples, four willows, four white chestnuts, two birches and one poplar. In 2005 only one maple tree and one whitebeam followed but new egg deposition sites could be found in the middle of October. All trees stood within a radius of 500 metres of the centre of infestation. In 2004 infested branches were carried to Freising and kept under conditions of quarantine. From this wood 47 adults emerged in 2004 and one specimen emerged in 2005. The beetles lived about three to four weeks. The antennae length, the body length and the body width were measured. The situation in Neukirchen/Inn is still tense and the monitoring has to be continued. 相似文献
93.
改革开放以来,随着我国畜牧业持续、健康和稳定的发展,畜产品质量与产量显著提高.据统计,2006年畜牧业总产值约1.4万亿元,占农业总产值的34%.肉、蛋、奶产量分别达到7 980、2 940和3 290万吨,比2000年分别增长58.8%、25.8%和193%,我国肉、蛋总产量已名列世界首位,奶产量跃居世界第五位.畜牧业的成就与我国畜禽疫病防治水平的提高密不可分,由于我国养殖业的生物安全管理比较差,主要靠疫苗免疫接种防控畜禽疫病.免疫接种安全、高效的疫苗是防控家禽疫病的关键,而实行禽用活疫苗的SPF化生产是保证疫苗纯净安全、有效的重要手段.…… 相似文献
94.
Genetic variation in the human insulin gene 总被引:22,自引:0,他引:22
Four recombinant lambda phages containing nucleotide sequences complementary to a cloned human preproinsulin DNA probe have been isolated from human DNA. Restriction analyses in conjunction with Southern hybridizations reveal two types of gene sequences. One isolate of each type was subjected to complete nucleotide sequence determination. The sequences contain the entire preproinsulin messenger RNA region, two intervening sequence. 260 nucleotides upstream from the messenger RNA capping site, and 35 nucleotides beyond the polyadenylate attachment site. Our results strongly suggest that these two gene types are allelic variants of a single insulin gene. 相似文献
95.
D Kwon IM Saadeldin SJ Kim SJ Park JT Kang HJ Park JH Moon OJ Koo G Jang BC Lee 《Reproduction in domestic animals》2014,49(6):995-999
Modifying electrical activation conditions have been used to improve in vitro embryo production and development in pigs. However, there is insufficient information about correlations of porcine embryo development with oocyte pre‐ and post‐activation conditions. The purpose of this study was to compare the developmental rates of porcine oocytes subjected to different mannitol exposure times, either pre‐ or post‐electrical activation, and to elucidate the reason for the optimal mannitol exposure time. Mannitol exposure times around activation were adjusted as 0, 1, 2 or 3 min. Blastocyst development were checked on day 7. Exposure of oocytes to mannitol for 1 or 2 min before electrical activation produced significantly higher blastocyst rates than exposure for 0 or 3 min. There was no significant difference in blastocyst rates when activated oocytes were exposed to mannitol for 0, 1, 2 or 3 min after electrical activation. While exposure of oocytes to mannitol for 1 min pre‐ and 3 min post‐activation showed significantly higher blastocyst development than 0 min pre‐ and 0 min post‐activation. It also showed higher maintenance of normal oocyte morphology than exposure for 0 min pre‐ and 0 min post‐activation. In conclusion, exposure of oocytes to mannitol for 1 min pre‐ and 3 min post‐activation seems to be optimal for producing higher in vitro blastocyst development of porcine parthenogenetic embryos. The higher blastocyst development is correlated with higher maintenance of normal morphology in oocytes exposed to mannitol for 1 min pre‐ and 3 min post‐activation. 相似文献
96.
Koch Eckhard Enders Melanie Ullrich Cornelia Molitor Daniel Berkelmann-Löhnertz Beate 《植物病害和植物保护杂志》2013,120(1):26-33
Journal of Plant Diseases and Protection - The paper describes in vitro and in vivo experiments with extracts from Primula root and Hedera helix aimed at characterizing their effect on Phyllosticta... 相似文献
97.
DNA sequence of two closely linked human leukocyte interferon genes 总被引:16,自引:0,他引:16
98.
The human gene for the beta subunit of nerve growth factor is located on the proximal short arm of chromosome 1 总被引:11,自引:0,他引:11
Fragments of the recently cloned human gene for the beta subunit of nerve growth factor (beta-NGF) were used as hybridization probes in analyzing two sets of rodent-human somatic cell hybrids for the presence of human beta-NGF sequences. Results from the first set of hybrids assigned the human beta-NGF gene to chromosome 1 and ruled out the presence of sequences of comparable homology on any other chromosome. With the second set of hybrids, which contained seven different, but overlapping, regions of chromosome 1, the NGF locus was mapped to band 1p22. 相似文献
99.
Recent results with Tokamak experiments provide insights into the problem of magnetic confinement. They demonstrate how to avoid anomalous transport and thus solve the major problems of Tokamak reactors: size, the production of 14-megaelectron volt neutrons, and maintenance. An alternate confinement system, the field-reversed configuration, confines beams of protons and boron-11. For the proton-boron-11 fusion reaction, the fusion products are all charged particles for which direct conversion is feasible and neutron flux is negligible. 相似文献
100.
A model of three-dimensional shear wave velocity variations in the mantle reveals a tilted low velocity anomaly extending from the core-mantle boundary (CMB) region beneath the southeastern Atlantic Ocean into the upper mantle beneath eastern Africa. This anomaly suggests that Cenozoic flood basalt volcanism in the Afar region and active rifting beneath the East African Rift is linked to an extensive thermal anomaly at the CMB more than 45 degrees away. In contrast, a low velocity anomaly beneath Iceland is confined to the upper mantle. 相似文献