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71.
H. K. da Silva L. D. Cassoli J. C. F. Pantoja P. H. R. Cerqueira J. P. P. Winckler T. B. Coitinho 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2017,67(1-2):71-75
Three experiments were performed to test if the time and storage conditions of milk samples, the preheating of samples in a water bath, as well as the carryover effect in laboratory analysis equipment could affect the pregnancy-associated glycoproteins (PAG) levels, and consequently the results of a pregnancy test. The pregnancy test used in both experiments uses the enzyme-linked immunosorbent assay method to measure the concentrations of PAG and classify the samples as pregnant, nonpregnant or suspicious. As a result, PAG levels showed no variation when the samples were analyzed up to 9 days after collection, whether stored in ambient temperature or refrigerated. The preheating of the samples in a water bath and prior to the analysis of SCC and composition also did not affect the levels of PAG, allowing the same sample used in the quality analysis to be used for the pregnancy test. 相似文献
72.
Wen Ganghua Tang Ping Yan Guangting 《保鲜与加工》1991,(6):32-37
A calculation formula of stirring energy in liquid steel is set up for bottom-blown O2 and CH,| in the combined blown converter, and the main factors which have an effect on stirring energy and the variation law of stirring energy in steel-making process are discussed. 相似文献
73.
Comparison Between Electrolysis and Reduction for Treatment of Spent Electroless Nickel Plating Bath
There are lots of residual nickel and organic compounds in the spent electroless nickel plating bath. It not only wastes resource but also causes environmental pollution if the wastewater is discharged without treatment. In this paper, electrolytic method and reduction method for treating spent electroless nickel plating bath were compared. The factors studied included reaction time, pH, temperature, effectiveness and cost. It was found that the recovery rate of nickel by reduction was 99.9% under the condition ofpH 6, 50℃ for 10 min. The purity of reclaimed nickel was 66.1%. This treatment needed about 16 g NaBH4 for a liter spent solution, which cost RMB 64 Yuan. For electrolysis method, with pH 7.6, 80℃, 0.45 A (current intensity) for 2 h, the recovery rate reached 97.3%. The purity was 88.5% for the reclaimed nickel. Moreover, it was found that through electrolysis, the value of TOC (Total Organic Carbon) decreased from 114 to 3.08 g·L^-1 with removal rate of 97.3%. The main cost of electrolysis came from electric energy. It cost about 0.09 kWh (less than RMB 0.1 Yuan) per liter wastewater. Compared with reduction, electrolysis had more advantages, so the priority of selection should be given to the electrolysis method for the treatment of spent electroless nickel plating bath. 相似文献
74.
本研究了测定有机抛光液中磷酸浓度的镁混合剂方法,硫酸和柠檬酸的存在对测定结果不产生影响。该方法测定的标准偏差低于0.5%,回收率为99.40%~100.00%。 相似文献
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Immersion challenge with low and highly virulent infectious salmon anaemia virus reveals different pathogenesis in Atlantic salmon,Salmo salar L. 下载免费PDF全文
D H Christiansen I Matejusova T Markussen M Kaldhusdal O B Dale S C Weli K Falk 《Journal of fish diseases》2015,38(1):3-15
The salmonid orthomyxovirus infectious salmon anaemia virus (ISAV) causes disease of varying severity in farmed Atlantic salmon, Salmo salar L. Field observations suggest that host factors, the environment and differences between ISAV strains attribute to the large variation in disease progression. Variation in host mortality and dissemination of ISAV isolates with high and low virulence (based on a previously published injection challenge) were investigated using immersion challenge. Virus dissemination was determined using real‐time PCR and immunohistochemistry in several organs, including blood. Surprisingly, the low virulent virus (LVI) replicated and produced nucleoprotein at earlier time points post‐infection compared to the virus of high virulence (HVI). This was particularly noticeable in the gills as indicated by different viral load profiles. However, the HVI reached a higher maximum viral load in all tested organs and full blood. This was associated with a higher mortality of 100% as compared to 20% in the LVI group by day 23 post‐infection. Immersion challenge represented a more natural infection method and suggested that specific entry routes into the fish may be of key importance between ISAV strains. The results suggest that a difference in virulence is important for variations in virus dissemination and pathogenesis (disease development). 相似文献
77.
Immune responses and gut morphology in Senegalese sole (Solea senegalensis) fed dietary probiotic supplementation and following exposure to Photobacterium damselae subsp. piscicida 下载免费PDF全文
Carolina Barroso Rodrigo O A Ozório António Afonso Julieta R E Moraes Benjamín Costas 《Aquaculture Research》2016,47(3):951-960
The aim of this study was to determine the effect of a dietary multi‐species probiotic on growth, gut morphology and immune parameters in Senegalese sole (Solea senegalensis). Fish were fed with two experimental diets, a control diet and the same diet supplemented with the probiotic for 72 days. A sub‐lethal bath challenge with Photobacterium damselae subsp. piscicida was performed after the growth trial. Intestine and blood samples were collected to study gut structure and plasmatic immune parameters. No significant differences were found in growth performance. The analysis of gut morphology showed a significant increase in intestinal villi height of Senegalese sole fed the probiotic. Regarding circulating leucocytes, dietary probiotic supplementation increased thrombocytes levels whereas a decrease in the proportion of lymphocytes was observed. No significant differences were observed in humoural immune parameters. Bath challenge differentially affected leucocyte counts and increased peroxidase activity. This study presents the possibility of using dietary probiotic supplementation to increase Senegalese sole welfare since gut morphology was positively affected. Although the immune response after a bacterial challenge was not modulated by dietary treatment, further studies would be instrumental to unravel eventual dietary benefits on immune mechanisms. 相似文献
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79.
Evaluating the spatial range of the effect of synchronized antiparasitic treatments on the abundance of sea lice Caligus rogercresseyi (Boxshall & Bravo, 2000) in Chile 下载免费PDF全文
Sea lice are the most important ectoparasites affecting farmed salmonids in marine water worldwide and pharmacological treatments are widely used to control their abundance. Synchronization of antiparasitic treatments among closely located salmon farms has been recently evaluated as a promising strategy for improving treatment performance. However, the optimum distance at which farms should synchronize their treatments is not clear. We used a repeated measures linear mixed effects model to evaluate the impact of two nationwide treatment synchronization procedures conducted in Chile in 2014 and 2015 on subsequent adult lice counts up to 13 weeks after the procedure. Each treatment synchronization procedure consisted of two 2‐week synchronization windows, in which farms were required to treat their fish. A period of 3 weeks elapsed between the two windows. Treatment synchronization was measured as the number of neighbouring farms that treated their fish within a certain geographical threshold, each of them weighted by its distance from the farm of interest. We tested four different thresholds: 5, 10, 20 and 30 km. The results indicate that the abundance of adult lice on farms that synchronized treatments with their neighbours within a distance of 5 km was lower than the abundance on non‐synchronized farms from weeks 4 to 11 after the procedure. Our findings suggest the treatment synchronization effect was distance dependent and greater when neighbouring farms up to 5 km joined the procedure. 相似文献
80.