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571.
572.
Successful Vitrification of In vivo Embryos Collected from Superovulated Japanese Black Cattle (Wagyu) 下载免费PDF全文
L An PP Ling X Zhu Y Liu F Zhang X Ma B Xu Y Wang Z Du L Yang F Xue A Bella GA Presicce F Du 《Reproduction in domestic animals》2016,51(2):255-261
The aim of this study was to determine whether vitrification is an effective method when used for Japanese Black Cattle (Wagyu) in vivo‐derived embryos, collected following a superovulation treatment and embryo transfer (MOET) programme. In vivo‐derived morula and blastocysts collected on day 7 after artificial insemination, were vitrified using a modified droplet vitrification (MDV) procedure and subsequently warmed for transfer (ET) into synchronized recipients. Fresh embryos, and embryos cryopreserved using a standardized slow freezing procedure (direct thaw/direct transfer, DT) served as ET controls. Two different follicle‐stimulating hormone (FSH) sources, Folltropin® Canada (FSH BAH, 24 donors) and a brand prepared by the Chinese Academy of Science (FSH CAS, 16 donors), were compared in a series of superovulation outcomes following well‐established FSH administration protocols. Following data analysis, the total number of ovulations recorded at the time of embryo flushing (10.5 vs 8.5; p = 0.28) and the total number of transferable embryos (6.2 vs 5.1; p = 0.52) were similar between the two FSH sources. ET for MDV (39.7%, n = 78), DT (35.2%, n = 71) and fresh controls (47.1%, n = 34) resulted in similar pregnancy rates (p > 0.05). When MDV was used, a higher pregnancy rate (42.6%) resulted from the transfer of vitrified morulae, when compared to the DT counterparts (24.3%), (p = 0.05). Transfer of vitrified morulae resulted also in higher pregnancy rate, when compared to the transfer of vitrified blastocysts (42.6% vs. 29.4%; p < 0.05). Transfer of DT blastocysts resulted in higher pregnancy rate than morulae, similarly cryopreserved (47.1% vs. 24.3%, p < 0.05). In conclusion, MDV is an effective alternative methodology for cryopreservation of in vivo‐derived embryos. This study gives also indication that, compared to vitrified blastocysts, MDV of morula stage embryos results in higher pregnancy rates following warming and transfer into synchronized recipients. 相似文献
573.
为探讨茵山莲水提物对四氯化碳(CCl4)诱导的小鼠急性肝损伤的保护作用及可能机制,以对后续茵山莲的深入研究及临床转化提供理论指导。将60只ICR小鼠随机分为6组,每组10只,分别为空白对照组、模型对照组、联苯双酯对照组、茵山莲低(1.17 mg·g-1)、中(2.34 mg·g-1)、高(4.68 mg·g-1)剂量组,按不同剂量药物每天灌胃1次,给药7 d。在末次给药1 h后,除空白对照组以外,其余各组小鼠腹腔注射0.2%四氯化碳构建急性肝损伤模型。12 h后小鼠眼球采血并分离血清,收集肝组织。采用生化分析检测血清总蛋白(TP)和谷胱甘肽S转移酶(GST)活性,肝组织中GST、琥珀酸脱氢酶(SDH)、过氧化氢酶(CAT)和总超氧化物歧化酶(T-SOD)活性,利用HE染色和Masson染色观察肝组织病理及肝纤维化情况,采用蛋白免疫印迹法和免疫组织化学法检测肝组织白介素1beta (IL-1β)、肿瘤坏死因子alpha (TNF-α)、血管生成因子A (VEGFA),金属基质蛋白酶9(MMP9)及转录因子NF-κBp65、蛋白激酶IKK、p38MAPK等蛋白表达及定位情况。结果表明,与模型对照组相比,2.34 mg·g-1茵山莲水提物能显著降低小鼠血清GST水平,显著升高肝内CAT水平,各组间T-SOD无显著差异,但2.34 mg·g-1茵山莲水提物组小鼠与空白对照组、模型对照组在肝GST、SDH和血清TP水平上无显著差异。2.34 mg·g-1茵山莲水提物能缓解CCl4诱导的小鼠肝病理损伤和纤维化病变,抑制肝IL-1β、TNF-α、VEGFA、NF-κBp65和IKK的表达。提示茵山莲水提物可能通过NF-κB和p38MAPK通路抑制肝氧化应激和炎症水平,从而缓解小鼠急性肝损伤。 相似文献
574.
575.
Agreement among three different equine venipuncture sites with regard to measurement of packed cell volume and total solids 下载免费PDF全文
The primary objective of this study was to determine the agreement between the packed cell volume (PCV) and total solids (TS) values in blood collected from the jugular vein (JV) in comparison with the cephalic vein (CV) and the transverse facial venous sinus (TFVS) in healthy adult horses. A total of 72 samples were taken from 24 horses. We found high agreement that reflects no clinically relevant differences between the PCV and TS values obtained from the CV or the TFVS in comparison with the JV in standing healthy adult horses. 相似文献
576.
施肥与灌水对硝态氮在土壤中残留的影响 总被引:34,自引:1,他引:34
通过田间试验研究不同施氮量与灌水量对春玉米和冬小麦田土壤中硝态氮分布与累积的影响,结果表明,春玉米收获后0~2 m土壤中累积硝态氮185.7~748.0 kg/hm2,其中1 m以上占57.9%~70.1%。由于施用氮肥而增加的硝态氮占施N量的1.8%(N 112.5 kg/hm2),50.7%(N 225 kg/hm2),56.7%(N 337.5 kg/hm2)和77.0%(N450 kg/hm2)。不施N和施N 112.5 kg/hm2时春玉米田土壤剖面没有明显累积峰;施N等于或高于225 kg/hm2时在60~80 cm土层有明显累积峰,施氮量高的峰值较高;施N 450 kg/hm2时在120~140 cm深度出现另一个累积高峰。冬小麦收获后土壤0~2 m硝态氮累积量为74.9~328.8 kg/hm2,其中1m以上占67.8%~90.7%。由于施用氮肥而增加的硝态氮占施N量的19.5%(N 112.5 kg/hm2),35.6%(N 225 kg/hm2),58.9%(N 337.5 kg/hm2)和56.4%(N 450 kg/hm2)。冬小麦田收获后土壤深层(1~2 m)没有明显的硝态氮累积,即使施氮量高达450 kg/hm2时也只在表层40 cm以上累积较多。不论是春玉米还是冬小麦,当生育期施氮量大于225 kg/hm2时0~2 m土层均有明显的硝态氮累积,施氮量高的累积量较高。施氮量是造成土壤中硝酸盐累积的主要因素,灌水量对春玉米田硝态氮的向下迁移有显著影响。 相似文献
577.
578.
H. Tunney F. J. Sikora D. Kissel A. Wolf L. Sonon K. Goulding 《Soil Use and Management》2010,26(2):126-132
Liming is necessary for good nutrient availability and crop growth. Lime use in Ireland is now the lowest in half a century. A recent study shows that grassland mineral soils in Ireland has a mean pH of 5.4 and mean lime requirement (LR) of 9.3 t/ha ground limestone. There have been a number of studies in the USA to re-evaluate LR, but little activity in the European Union (EU) in recent years. The primary aim of our research was to compare five methods for estimating LR, which included the Shoemaker–McLean–Pratt (SMP) buffer method currently used in Ireland (IRL), the Sikora buffer method used at the University of Kentucky (UKY), Ca(OH)2 titration used at University of Georgia (UGA), the modified Mehlich buffer method used at Penn State University (PSU) and the UK RothLime model, using 57 representative grassland mineral soils from Ireland with a pH range from 4.8 to 6.6. The secondary aim was to explore an alternative to the SMP buffer that does not involve the use of toxic chemicals. The results show good agreement between the pH measured by the Irish and three US laboratories and reasonably good agreement in LR estimated by five methods. The main conclusions are: (1) a significant proportion of grassland on mineral soils in Ireland would benefit from liming to increase soil pH, (2) on average, LRs as recommended in Ireland are higher than those advised elsewhere , ( 3) the target pH in Ireland is high compared with that in other countries and should be reduced from pH 6.5 to 6.2, (4) the SMP buffer method should be replaced by a suitable alternative and, in principle, any of the four methods studied would be suitable, (5) to find the most suitable alternative for accurate LR advice it would be necessary to compare the different methods to the actual LR from incubation of representative soils with calcium hydroxide. 相似文献
579.
Commercial soybean hulls (14.6% crude protein) were pin milled and then air classified into five fractions to determine whether the hull structure can be disrupted and the protein constituents concentrated. The number of pin millings had only a small effect on the weight distribution of the five fractions. After one grinding, the sum of fractions 1 and 2 (<15–18 μm) represented only 3% of total hulls, and on three grindings, they amounted to only 6% of the hulls. Fraction 3 (19–24 μm) shifted from 16 to 20% with three grindings, while fraction 4 (25–30 μm) remained unchanged at 5%. Fraction 5 (>30 μm) shifted from 75 to 69% on three pin millings to compensate for the shifts noted in fractions 1–3. Scanning electron microscopy revealed that fractions 1 and 2 consisted of the parenchymal cell layers (innermost portion) of the hulls; these fractions had three times the protein content and more than twice the amount of lipids found in the ground starting material. Fraction 3 contained many of the hourglass cells typically found in the middle layer of the hulls plus parenchyma cell material and exhibited about twice the amount of protein and lipid found in the starting hulls. Fraction 4 included large hourglass cells plus globular material and contained about twice the amount of protein and about one and one‐half times the lipid of the starting material. Fraction 5 consisted primarily of clumps of palisade cells (outer cellular layer) adhering to each other and had a lower protein and lipid content than the starting hulls. Thus, pin milling causes some selective disruption of the hulls where parenchyma cell layers and hourglass cells are partially released. The palisade cells, however, are the most difficult to disrupt and constitute the fraction most resistant to pin milling. Our findings suggest that pin milling soybean hulls in combination with air classification can be used to concentrate the proteins and lipids in the fines fractions. 相似文献
580.
Sebastian Wolf Werner EugsterCatherine Potvin Nina Buchmann 《Agricultural and Forest Meteorology》2011,151(8):1139-1151
Pasture and afforestation are land-use types of major importance in the tropics, yet, most flux tower studies have been conducted in mature tropical forests. As deforestation in the tropics is expected to continue, it is critical to improve our understanding of alternative land-use types, and the impact of interactions between land use and climate on ecosystem carbon dynamics. Thus, we measured net ecosystem CO2 fluxes of a pasture and an adjacent tropical afforestation (native tree species plantation) in Sardinilla, Panama from 2007 to 2009. The objectives of our paired site study were: (1) to assess seasonal and inter-annual variations in net ecosystem CO2 exchange (NEE) of pasture and afforestation, (2) to identify the environmental controls of net ecosystem CO2 fluxes, and (3) to constrain eddy covariance derived total ecosystem respiration (TER) with chamber-based soil respiration (RSoil) measurements. We observed distinct seasonal variations in NEE that were more pronounced in the pasture compared to the afforestation, reflecting changes in plant and microbial activities. The land conversion from pasture to afforestation increased the potential for carbon uptake by trees vs. grasses throughout most of the year. RSoil contributed about 50% to TER, with only small differences between ecosystems or seasons. Radiation and soil moisture were the main environmental controls of CO2 fluxes while temperature had no effect on NEE. The pasture ecosystem was more strongly affected by soil water limitations during the dry season, probably due to the shallower root system of grasses compared to trees. Thus, it seems likely that predicted increases in precipitation variability will impact seasonal variations of CO2 fluxes in Central Panama, in particular of pasture ecosystems. 相似文献