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【目的】探究中药组方"回乳康"对回乳期奶牛血清雌激素(Estrogen,E)、孕酮(Progesterone,P4)和转化生长因子β1(Transforming growth factorβ1,TGF-β1)含量的影响。【方法】选取即将干乳日产奶量为(15.42±0.71)kg的健康奶牛80头,随机分为4组,每天饲喂0(对照组)、400、500和600 g"回乳康"中药,采用逐渐干奶法回乳,分别在回乳第0、1、3、5、7、9和11天采集奶牛尾静脉血,并记录奶牛单日产奶量,采用ELISA法检测血清E、P4和TGF-β1含量。【结果】0、400、500和600 g处理回乳时间分别为11、7、5和5 d;各组奶牛血清E含量在回乳期均随时间推移呈下降趋势,对照组下降趋势较中药组慢;对照组奶牛血清P4含量在回乳期变化不显著,而中药组奶牛血清P4含量均随时间推移呈上升趋势,在回乳期之后下降,但下降后仍极显著高于对照组;各处理回乳期奶牛血清TGF-β1含量均呈上升趋势,而在回乳期之后中药组奶牛血清TGF-β1含量呈下降趋势;回乳期奶牛血清E、TGF-β1含量和日产奶量两两间均呈极显著相关,血清P4含量与血清E、TGF-β1含量、日产奶量均无显著相关性。【结论】在奶牛回乳过程中,添加中药组方"回乳康"能显著促进回乳期奶牛回乳,E是奶牛回乳的负调控激素,TGF-β1是正调控因子,而P4对回乳无明显影响。 相似文献
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浙江省油菜花期降水量风险评估 总被引：1，自引：0，他引：1
对浙江省66个县市(区)1971—2014年油菜花期降水量及油菜产量资料进行统计分析,并基于信息扩散的风险评估模型,对浙江省油菜花期降水量在各级降水量下的超越概率进行计算分析,评估各地油菜花期面临的旱涝风险;同时分析了浙江省油菜花期各级降水量风险值与油菜产量变化之间的关系。结果表明:油菜花期降水量严重过剩的风险高值区主要位于浙西南地区,降水量短缺风险高值区主要位于浙江省沿海岛屿及宁波的部分县市;浙江省油菜花期降水量短缺基本可以通过灌溉得到改善,但油菜减产与花期降水量过多显著相关,油菜花期降水量300 mm是油菜是否减产的阈值。该结果可为油菜种植合理布局及农业保险政策提供科学依据。 相似文献
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小麦种子萌发早期淀粉降解关键酶活性及基因表达量研究 总被引：3，自引：1，他引：2
为研究小麦种子萌发早期淀粉降解关键酶活性及其基因表达量变化,以山农17为试验材料,测定了不同温度条件下萌发的小麦种子中的淀粉、可溶性糖含量及相关酶(淀粉酶和淀粉磷酸化酶)活性,并采用实时荧光定量PCR技术测定各酶相关基因相对表达量。结果显示,不同温度条件下萌发的小麦种子,淀粉含量随萌发进程以不同的速率呈下降趋势,可溶性糖含量呈先下降后上升趋势,α-淀粉酶、淀粉磷酸化酶活性和呼吸速率整体呈上升趋势,以上各指标均在露白前后有明显的变化;β-淀粉酶呈现双峰变化趋势,且一直保持较高活性;α-淀粉酶和淀粉磷酸化酶基因的相对表达量均呈上升趋势,且与酶活性呈极显著相关。以上结果表明,在小麦种子萌发早期,温度能强烈影响萌发过程中淀粉降解关键酶基因的表达量;α-淀粉酶和淀粉磷酸化酶在种子置床初期即可被检测到活性,且受其编码基因的调控作用显著,在种子萌发过程中具有重要作用。 相似文献
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Adrenal ascorbic acid was determined in nonstressed, newborn rats. The maturational pattern of the acid consists of high resting levels early in development, a marked decrease during a period between 8 and 12 days, and a subsequent return to high levels. The onset of the maturational pattern is accelerated by previous manipulation of the newborn rat. 相似文献
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基于GreenSeeker的水稻氮素估测 总被引：1，自引：1，他引：0
为研究水稻植株氮素指标与GreenSeeker植被指数的定量关系,通过设置不同年份、不同氮肥水平的田间试验,于移栽后定期使用GreenSeeker获取冠层归一化差值植被指数(NDVI)和比值植被指数(RVI),并同步破坏性取样获取植株生物量和氮含量,分析不同品种和不同氮营养条件下氮素和植被指数(NDVI和RVI)变化规律,建立基于NDVI和RVI的氮素监测模型。结果表明,植株氮含量可以基于NDVI和RVI分时期进行估算,植株氮积累量可以被分阶段反演。利用GreenSeeker可以实现水稻氮素快速无损监测,为水稻氮肥精确管理提供技术支持。 相似文献
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本文通过对甘肃省河西地区不同生长期草木樨中总香豆素的测定,结果表明:草木樨中香豆素的含量在营养期最高,开花期次之,结实期最低;花中最高,叶中次之,茎中最低:因地区不同其含量也有差异。 相似文献
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研究了板栗雌花芽临界分化期和雄花芽形态分化期可溶性糖、蔗糖、淀粉、蛋白质含量的变化规律和积累水平。结果表明,生理分化期雌花芽可溶性总糖和蔗糖含量的变化似抛物线,形态分化期的雄花芽含量呈直线下降;2类芽淀粉含量均呈＂S＂型变化,交叉后雄升雌降;蛋白质含量均呈上升态势,中后期雌花芽上升幅度比雄花芽大。雌花芽临界分化结束时,可溶性总糖、蔗糖和可溶性蛋白质含量雌花芽极显著高于雄花芽,淀粉含量极显著低于雄花芽。2类花芽分化时均需丰富的营养物质为基础,雌花芽更高,且相互竞争和制约。 相似文献
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M. S. Grigorov K. K. Zhiburtovich Yu. A. Mazhaiskii A. V. Il’inskii 《Russian Agricultural Sciences》2012,38(3):242-246
It is shown that modern methods of land amelioration cannot maintain optimum root-zone soil moisture every day during the entire vegetation period; in practice, it is calculated with consideration of allowable limits. A method is given for calculating the ranges of optimum groundwater levels during regulation of the water regime in soils of ameliorated lands. 相似文献
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两种转Bt基因棉杀虫蛋白Cry1Ac表达量的检测 总被引：1，自引：0，他引：1
用EnvirologixCry1Ab/Cry1Ac平板试剂盒检测了两种转Cry1Ac基因的棉花品系 (NUCOTN33B、NUCOTN99B) 以及常规对照品系 (苏棉 12) 不同生育期主茎嫩叶、侧枝嫩叶、蕾及蕾的苞叶中杀虫蛋白Cry1Ac的含量。结果表明, 两种转Bt基因棉主茎嫩叶杀虫蛋白Cry1Ac的含量随生育期的推移呈明显下降趋势, 花铃期 (NUCOTN33B和NUCOTN99B分别为 4 43和 2 93μg·g-1 ) 和吐絮期 (3 87和 2 86μg·g-1 ) 的含量分别降至苗期第 6叶 (7 64和 8 38μg·g-1 )的 58%、35%和 51%、34%; 相同时期的主茎嫩叶和侧枝嫩叶中Cry1Ac的含量均显著高于蕾及蕾的苞叶, 前两者均为后两者的两倍以上。 相似文献
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为研究不同单元化运输条件对活体虾夷扇贝Patinopecten yessoensis存活率及其主要营养成分的影响,将净化暂养后的活体虾夷扇贝放入4种不同单元化运输箱中(不加冰聚乙烯保温箱组、加冰聚乙烯保温箱组、低温半导体保温箱组、5℃恒温箱组),测定运输箱内外温度、湿度,以及虾夷扇贝存活率、糖原、粗蛋白质和粗脂肪等指标的变化。结果表明:在密闭的单元化运输条件下,箱内温度及制冷方式影响着活贝的存活率,不加冰聚乙烯保温箱组、加冰聚乙烯保温箱组、低温半导体保温箱组、5℃恒温箱组虾夷扇贝全部死亡的时间分别为48、64、112、104 h;随运输时间的延长,4组虾夷扇贝的糖原、粗蛋白质和粗脂肪含量总体均呈下降趋势,存活期内不同单元化运输条件下的糖原和粗蛋白质含量均呈显著性差异(P0.05),低温半导体保温箱组和5℃恒温箱组虾夷扇贝的糖原、粗蛋白质含量随时间的变化缓于其他两组,但64~96 h时,低温半导体保温箱组和5℃恒温箱组间粗蛋白质含量无显著性差异(P0.05);存活期内不同单元化运输条件对虾夷扇贝粗脂肪含量的影响不显著(P0.05),但在0~40 h时其脂肪含量随时间变化显著(P0.05);低温半导体保温箱组和5℃恒温箱组虾夷扇贝至糖原、粗蛋白质和粗脂肪含量较低所需时间为96 h,比不加冰组长56 h,比加冰组长48 h。研究表明,使用半导体和压缩机有效制冷的低温条件可使得活体虾夷扇贝糖原、粗蛋白质和粗脂肪消耗减缓,存活期延长。 相似文献
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用２只装有瘤胃瘘管和皱胃瘘管的本地健康空怀母山羊做自身对照试验,禁食２４ｈ后,在试验１期从瘤胃瘘管分４次分别输注乙酸,丙酸、丁酸和生理盐水,试验２期从皱胃瘘管重复上述操作。每次都从颈静脉套管采血,用放射免疫法测定血浆胃动素含量。结果表明,输注挥发性脂肪酸（ＶＦＡ）可提高山羊血浆胃动素水平,瘤胃内输注乙酸、丙酸、丁酸后的血浆胃动素水平升高与对照组相比,差异均极显著（Ｐ〈０．０１）;皱胃内输注丙酸或丁 相似文献
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High-resolution holocene environmental changes in the thar desert, northwestern india 总被引：2，自引：0，他引：2
Enzel Y Ely LL Mishra S Ramesh R Amit R Lazar B Rajaguru SN Baker VR Sandler A 《Science (New York, N.Y.)》1999,284(5411):125-128
Sediments from Lunkaransar dry lake in northwestern India reveal regional water table and lake level fluctuations over decades to centuries during the Holocene that are attributed to changes in the southwestern Indian monsoon rains. The lake levels were very shallow and fluctuated often in the early Holocene and then rose abruptly around 6300 carbon-14 years before the present (14C yr B.P.). The lake completely desiccated around 4800 (14)C yr B.P. The end of this 1500-year wet period coincided with a period of intense dune destabilization. The major Harrapan-Indus civilization began and flourished in this region 1000 years after desiccation of the lake during arid climate and was not synchronous with the lacustral phase. 相似文献
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日粮蛋白质水平对绒山羊公羊养分消化和精液品质的影响 总被引：1，自引：1，他引：0
研究了日粮蛋白水平对绒山羊种公羊养分消化和精液品质的影响。试验选取24只在配种期(2007-09-01—12-10)的辽宁绒山羊成年种公羊为试验动物,采用单因子完全随机区组试验设计,随机分为3组(低蛋白组水平10.5%(w)、中蛋白组水平12.1%(w)、高蛋白组水平13.5%(w),皆为DM),每组8只。结果表明:1)日粮蛋白质水平对绒山羊种公羊的干物质(DM)、粗蛋白(CP)和中性洗涤纤维(NDF)的表观消化率没有影响(P>0.05);但提高日粮蛋白水平有利于酸性洗涤纤维(ADF)的消化,以中蛋白水平12.1%为宜。2)日粮不同蛋白水平对各组采精量、精子密度、精子活力、畸形率等各项精液品质指标均差异不显著(P>0.05);但整个试验期间以中蛋白组的精子活力最高,精子畸形率最低,精液品质最好;随试验时间的增加日粮不同蛋白水平使精子活力上升、畸形率下降,精液品质变好。推荐CP水平12.1%作为辽宁绒山羊种公羊适宜的日粮蛋白质水平。 相似文献
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CHEN Long MAO Xin-zhi WANG Bing-yun Award Daugschies J.Gonzalez-Gallego 《中国农业科学(英文版)》2002,1(2):221-226
Action mechanism of blood cell immune response in water buffaloes against acute infection with F. Hepatica was studied. The results showed that after water buffaloes were infected, the total levels of WBC surpassed control group during whole infection period; Eosinophiles (%) of DC were higher than control group at the 2nd week until 19th week, and then dropped and was close to control group; Neutrophiles(%)was low or significantly lower than control group within the 5 - 16th weeks; The total levels of lymphocytes (%) was lower than control group during the whole infection period; T-lymphocytes (%) dropped significantly, but B-lymphocytes(%) had opposite changes from the first week of infection, and they were close to the control group after 11 weeks; RBC-CR1 and RBC-IC rosette rates dropped and rose during 2 - 16 and 2- 18 weeks, respectively, and then approached the same between both groups. It was suggested that the violent changes of specific and nonspecific immune responses in water buffaloes with acute F. hepatica infection are related with the mechanism against infection with F. hepatica together. 相似文献
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酸奶具有抑制肠道内腐败菌的生长繁殖、克服乳糖不耐症、降低胆固醇含量,甚至抗癌等功能。发酵菌种是生产优质酸奶的关键,保加利亚乳杆菌(现更名为德氏乳杆菌保加利亚亚种,Lactobacillus delbrueckiisubsp.bulgaricus)是酸奶发酵中最常见的发酵菌种之一。为进一步了解保加利亚乳杆菌的发酵特性,本文对保加利亚乳杆菌的产酸、产黏、产香(主要是乙醛)特性进行了测定。结果表明,该菌种产酸和产黏能力在发酵期强,后发酵期间能力较弱;产香能力则在后发酵期间逐渐增强。 相似文献
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Androgens prevent normally occurring cell death in a sexually dimorphic spinal nucleus 总被引：11，自引：0，他引：11
The spinal nucleus of the bulbocavernosus (SNB) contains many more motoneurons in adult male rats than in females. Androgens establish this sex difference during a critical perinatal period, which coincides with normally occurring cell death in the SNB region. Sex differences in SNB motoneuron number arise primarily because motoneuron loss is greater in females than in males during the early postnatal period. Perinatal androgen treatment in females attenuates cell death in the SNB region, reducing motoneuron loss to levels typical of males. The results suggest that steroid hormones determine sex differences in neuron number by regulating normally occurring cell death and that the timing of this cell death may therefore define critical periods for steroid effects on neuron number. 相似文献
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When Osborne-Mendel female rats (white) were mated with both an Osborne-Mendel and an NIH Black rat male during the same breeding period, litters were born which contained both Osborne-Mendel (white) and crossbred (grey to black) offspring. The Osborne-Mendel and crossbred animals developed widely different levels of caries activity even though they were exposed to identical environmental conditions during the intrauterine, preweaning, and experimental periods. These findings are indicative of a strong heritable influence on the development of dental caries. 相似文献