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排序方式: 共有533条查询结果,搜索用时 15 毫秒
91.
92.
Liu WB Chuang ST Shyu CL Chang CC Jack A Peh HC Chan JP 《Acta veterinaria Hungarica》2011,59(2):247-256
The objective of this study was to improve the reproductive efficiency of dairy cows with puerperal metritis (PM) subsequent to retained placenta (RP) using a two-step treatment strategy. A total of 188 postpartum cows, aged from 2 to 8 years, were utilised for 2 experiments. In Experiment 1, cows affected with RP/PM were randomly assigned to two treatment groups. Cows in Group A (n = 17) were treated with 600 mg of ceftiofur intramuscularly for 3 days followed by intrauterine lavage with 0.1% chlorhexidine and infusion with 0.5% povidoneiodine, while cows in Group B (n = 16) received two intrauterine infusions, first with 5 g of oxytetracycline and then with 0.5% povidone-iodine. Cows with normal postpartum findings were regarded as the healthy control group (n = 26). Ultrasonographic examination revealed that the ovarian activities including the appearance of a dominant follicle and days to first ovulation of the cows in Group A during the early postpartum period differed from those of Group B (P < 0.05), which coincided with the results of uterine swabbing for bacteriology. In Experiment 2, cows with normal postpartum findings were allocated to Group D (n = 78), which received an ovulation protocol (GnRH - 7 d PGF2α - 48 h hCG - 24 h AI) on day 50 ± 2 postpartum. Cows affected with PM were randomly divided into two groups, Group E (n = 25) combined the treatments applied in Groups A and D, while Group F (n = 26) repeated the treatment administered in Group E except for uterine lavage. The results indicated that the pregnancy rate within 150 days postpartum and the mean days open in Group E (76.0% and 106.3 ± 4.6 days, respectively) were significantly different from those in Group F (38.5% and 137.9 ± 10.9 days, respectively) (P < 0.05). This study suggests that reproductive efficiency could be improved by using the two-step treatment to regulate uterine involution and an early resumption of ovarian function in cows with RP/PM. 相似文献
93.
Four of five major cultivars of the potato (Solanum tuberosum L. ssp.tuberosum) from different sources were found to vary genetically. This variability was detected by an electrophoretic study of enzymatic activity for alkaline phosphatase and glucosephosphate isomerase. An examination of red cultivars from Beltsville, Md. suggests that the apparent intracultivar variability observed for Red Pontiac may be due to cultivar mislabeling rather than mutation or mitotic recombination. The results of this study raise concerns about potato cultivar certification and interpretations of some of the previous cultivar work. We suggest that a more extensive survey of intracultivar variability be carried out. Further, we suggest that these genetic markers and others could be used in cultivar identification. 相似文献
94.
Summary A cross was made between a unique highly branched, early flowering line, U. S. Department of Agriculture (USDA) 846-1 (P1; 7 to 11 lateral branches), and ‘Topmark’ (P2; 2 to 4 lateral branches), a U.S. Western Shipping melon, to produce an array of 119 F3 families. Subsequently, a genetic analysis was conducted at Arlington and Hancock, Wisconsin in 2001 to evaluate the segregating
progeny for factors likely involved in yield-formation, including days to anthesis, percentage of plants with early pistillate
flowering, primary branch number, fruit number and weight per plant, average weight per fruit, percentage of plants with predominantly
crown fruit set, and percentage of plants with early maturing fruit. Although, genotype × environment (G × E) interactions
were important for some traits (e.g., fruit number and fruit weight), considerable additive and/or dominance variance was
detected for all traits. This research provides critical data associated with highly branched melon germplasm including trait
correlations and heritabilies (broad- and narrow-sense ranged between 0.28 and 0.91) that used judiciously will allow the
development high yielding melon cultivars with early, basally concentrated fruit suitable for once-over or machine harvesting
operations. 相似文献
95.
96.
Shuxian Li Anatoliy Lygin Olga Zernova Vera Lozovaya Glen L.Hartman Jack M.Widholm 《大豆科学》2008,27(2):275-282
摘要:茄病镰刀菌(Fusarium solani f.sp.glydne)是一种土生细菌,通过侵染大豆根系引发猝死综合症。利用温室盆栽试验和须根培养试验研究了接种茄孢镰刀菌对13个不同基因型大豆的影响。结果表明:接种后所有盆栽大豆主根都有明显深褐色的侵染病斑;移植后21d测定了盆栽植株叶部发病程度,Peking表现最为严重,然后依次为Spencer,Ripley,P3981,Williams82,Essex,Forrest,Iroquois,PI520733,Hartwig,PI567650B,Jack,和PI567374。叶部发病程度与冠高(r=-0.422,P=0.0018)、冠重(r=-0.857,P〈0.0001)和根重(r=-0.732,P〈0.0001)呈显著负相关。主根病斑长度与叶部发病程度没有相关性,表明大豆对病原菌的抗性不能仅通过根系得到充分控制。对培养的大豆须根接种茄病镰刀菌菌丝体10d后,不同基因型大豆的菌落直径的变化范围为17—40mm,差异显著(P=0.05),其中Spencer和Peking须根上的菌落直径显著(P=0.05)大于PI567374和PI520733。对Spencer和PI567374的须根接种10灿茄病镰刀菌常量成分悬浮液,10d后菌落直径分别为50和38mm,差异显著(P=0.05)。通常,不同基因型大豆间茄病镰刀菌在培养须根上的生长与整株的症状间有一定的相关性,但不总是这样,这是因为即使根系对毒素产生抗性来减少叶部病害症状,但并不是所有的大豆都表现出明显的根系抗性。 相似文献
97.
Over the last decade, algae have been explored as alternative and sustainable protein sources for a balanced diet and more recently, as a potential source of algal-derived bioactive peptides with potential health benefits. This review will focus on the emerging processes for the generation and isolation of bioactive peptides or cryptides from algae, including: (1) pre-treatments of algae for the extraction of protein by physical and biochemical methods; and (2) methods for the generation of bioactive including enzymatic hydrolysis and other emerging methods. To date, the main biological properties of the peptides identified from algae, including anti-hypertensive, antioxidant and anti-proliferative/cytotoxic effects (for this review, anti-proliferative/cytotoxic will be referred to by the term anti-cancer), assayed in vitro and/or in vivo, will also be summarized emphasizing the structure–function relationship and mechanism of action of these peptides. Moreover, the use of in silico methods, such as quantitative structural activity relationships (QSAR) and molecular docking for the identification of specific peptides of bioactive interest from hydrolysates will be described in detail together with the main challenges and opportunities to exploit algae as a source of bioactive peptides. 相似文献
98.
Jack R. Plimmer 《Pest management science》1993,39(2):103-108
For registration, the United States Environmental Protection Agency (USEPA) separates pesticides into conventional chemical pesticides and biochemical and microbial pesticides. Natural products generally fall into the latter category. The USEPA has specified the test requirements for registration in the United States in the guidelines for registration of biorational pesticides (Subdivision M of 40 CFR Part 158). A discussion of the regulatory issues requires some reference to the accompanying scientific developments. The potential application of chemicals that affect insect behavior and development appeared an extremely promising approach to the reduction of adverse environmental and health impacts associated with many conventional pesticides. In addition to these benefits, the new biopesticides generally affected a very specific range of target species. However, although juvenile hormones and semiochemicals offer exciting new approaches to pest control, and are potentially valuable components of pest management strategies, acceptance of these techniques has been slow. Commercial development has been difficult for several reasons. Regulatory requirements may appear burdensome. Unconventional pest-control technologies may call for special formulations or application equipment. It may not be easy to establish the efficacy of non-lethal potential techniques. Investigators who derive funds from the public sector may have neither responsibility nor resources to carry the technology beyond the experimental stage. Because most activities in this field have been heavily research-oriented, few workers have possessed the additional resources to obtain safety data or data to satisfy regulatory requirements. Difficulties in preparing and administering guidelines for registration of biopesticides lie in the novelty of the pest control agents and the diversity of the techniques involved in their effective use. Rapid advances in molecular biology and other disciplines continually strain the capabilities of regulators who are responsible for making safety assessments regarding pest-control agents. Although regulatory authorities are familiar with conventional pesticides, safety assessment of biopesticides calls for totally different approaches. 相似文献
99.
Linda J. Konde DVM Robert H. Wrigley BVSc MS DVR MRCVS Richard D. Park DVM PhD Jack L. Lebel DVM PhD 《Veterinary radiology & ultrasound》1985,26(3):74-81
Eight dogs with renal neoplasia were radiographically and sonographically examined. An enlarged, nonopacified kidney was seen on the excretory urogram in four dogs, but differentiation between a solid mass or severe hydronephrosis was not possible. The excretory urogram suggested an avascular lesion in one kidney, but differentiation between solid or cystic disease was not possible. Renal neoplasia was diagnosed in two dogs by excretory urography. Radiographic examination suggested splenic neoplasia in one dog. Solid masses were sonographically diagnosed in all dogs. A metastatic lesion was sonographically diagnosed in the opposite kidney of one dog that was missed on the radiographic examination. Ultrasonography com-plemented radiography as a diagnostic modality in eliciting additional information on renal disease. Sonograms did not allow determination of tumor cell type or whether the tumor was benign or malignant. 相似文献
100.