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141.
健康妊娠奶牛20头随机分为照射组和对照组各10头。照射组奶牛分别于分娩前10~3d和产后1~3d,用TDP辐射仪交替照射百会和后海穴区,每天1次,60min。奶牛分别于分娩前20、15、10、5、3、1d,1~4h和产后1~4h、1、3、15d,颈静脉采血样。检测血样的ηb80s-1,ηb20s-1,ηp,PCV,ηr,RI,AI和血浆的Glu,TP,FG的含量。与对照组比较,结果:TDP穴区照射对奶牛分娩前和后一定时期内的ηb80s-1,ηb20s-1和ηp具有一定调整作用;调整和改善分娩过程中的血糖含量和血液的流动性与变形性,减少血液丢失等,从而提高机体分娩应激反应综合适应能力。其作用机理可能是TDP辐射红外热能的经、穴感应调整作用和机体产生的生物能量效应等的综合。 相似文献
142.
Understanding plant water-use patterns is important for improving water-use efficiency and for sustainable vegetation restoration in arid and semi-arid regions. However, seasonal variations in water sources and their control by different sand-fixing plants in water-limited desert ecosystems remain poorly understood. In this study, stable isotopic ratios of hydrogen (δ2H) and oxygen (δ18O) in precipitation, soil water, groundwater, and xylem water were determined to document seasonal changes in water uptake by three representative plant species (Pinus sylvestris var. mongolica Litv., Amygdalus pedunculata Pall., and Salix psammophila) in the northeastern Mu Us sandy land, Northwest China. Based on the depth distribution and temporal variation of measured gravimetric soil water content (SWC), the soil water profile of the three species stands was divided into active (0.01 g g-1 < SWC < 0.08 g g-1, 20% < coefficient of variation (CV) < 45%), stable (0.02 g g-1 < SWC < 0.05 g g-1, CV < 20%), and moist (0.08 g g-1 < SWC < 0.20 g g-1, CV > 45%) layers. Annually, P. sylvestris, A. pedunculata, and S. psammophila obtained most water from deep (59.2% ±9.7%, moist layer and groundwater), intermediate (57.4% ±9.8%, stable and moist layers), and shallow (54.4% ±10.5%, active and stable layers) sources, respectively. Seasonally, the three plant species absorbed more than 60% of their total water uptake from the moist layer and groundwater in the early (June) dry season; then, they switched to the active and stable layers in the rainy season (July–September) for water resources (50.1%–62.5%). In the late (October–November) dry season, P. sylvestris (54.5%–66.2%) and A. pedunculata (52.9%–63.6%) mainly used water from stable and moist layers, whereas S. psammophila (52.6%–70.7%) still extracted water predominantly from active and stable layers. Variations in the soil water profile induced by seasonal fluctuations in precipitation and groundwater levels and discrepancies in plant phenology, root distribution, and water demand are the main factors affecting the seasonal water-use patterns of artificial sand-fixing plants. Our study addresses the issue of plant water uptake with knowledge of proportional source-water use and reveals important implications for future vegetation restoration and water management in the Mu Us sandy land and similar desert regions around the world. 相似文献
143.
不同冰温温度对山楂果实生理及品质的影响 总被引:1,自引:1,他引:0
为延长山楂果实的保鲜期,提高果实贮藏品质,筛选适宜山楂果实冰温温度参数。在以普通冷藏(0±0.5)℃,以及果实温度为-0.4、-1.0、-1.6℃的4个不同温度的贮藏条件下,对贮藏期间‘敞口’山楂果实采后生理及品质变化进行研究。结果表明,-1.0℃的冰温处理降低了山楂果实的乙烯生成速率和最大生成量,减缓了果肉硬度、可滴定酸(TA)和维生素C(Vc)含量的下降,有效抑制了果肉中丙二醛(MDA)的积累,减轻了贮藏后期多酚氧化酶(PPO)活性的上升和酚类物质含量的减少,进而延缓了山楂果实的生理衰老进程,维持了山楂果实的良好贮藏品质;而在贮藏160天后,-1.6℃的冰温处理的山楂果实乙烯释放峰值显著增高,TA和Vc降解迅速,MDA含量显著上升,PPO活性明显上升和酚类物质含量迅速减少,加速了果实的褐变速率,生理伤害症状明显,品质劣变严重。综上所述,在-1.0℃的冰温条件下,山楂果实生理代谢被有效抑制且未出现生理伤害,贮藏效果最佳。 相似文献
144.
煤矸石山立地条件与林业复垦研究——以山西统配煤矿为例 总被引:5,自引:0,他引:5
煤矸石是我国工业排弃数量最大的固体废弃物,它带来的危害是压占土地、破坏景观、污染环境。山西省作为能源重化工基地,煤矸石的堆积、污染问题尤为突出,改造任务异常艰巨。研究结果表明:煤矸石成山状堆积,仅表层10cm左右有物理风化,下层很难风化;煤矸石山可蓄一定的水分,但地表高温,养分贫瘠,特别是自燃后的矸石强酸高盐,给植被恢复带来了极大的困难;大量煤矸石山的基本出路是进行林业复垦。其适用技术体系包括:①做好水保工程,保留地表黑色风化层;②引入先锋草种、树种;③薄盖土后直播;④加强施肥、病虫害防治等管理。 相似文献
145.
DXDK-40型自动包装机成型器及热压封头改进设计 总被引:1,自引:0,他引:1
在包装工程实验教学中,发现DXDL型立式全自动包装机存在供膜走偏、热封皱褶甚至密封不好等问题。本文结合机械设计的相关理论,探索出影响薄膜供给和材料成型缺陷的根本原因是热压封头的封合压力混乱以及成型器的外部曲线存在拐点突变。针对上述问题,重点研究热压封头和象鼻成型器的改进方案及设计方法,从理论上对该立式包装机的封合和成型进行创新性设计。 相似文献
146.
AIM:To investigate the effects of radix pseudostellariae on cardiac function and matrix metalloproteinases (MMPs) in rat chronic heart failure induced by coronary artery ligation. METHODS:Rat model of chronic heart failure was produced by ligating the coronary artery for 6 weeks. The cardiac functions were determined by observing the hemodynamics parameters. mRNA expressions of MMP-2 and MMP-9 in left ventricular tissue were detected by RT-PCR and activities of MMPs were assayed by zemography.RESULTS:Cardiac function was remarkable turbulence after coronary artery ligation 6 weeks, according to the results of the hemodynamics. The mRNA contents and activities of MMP-2 and MMP-9 in left ventricular tissue were significantly elevated. Radix pseudostellariae remarkable ameliorated the cardiac functions, inhibited the mRNA contents and activities of MMP-2 and MMP-9 in left ventricular tissue of rat with chronic heart failure after continued 5 weeks treated with decoction of radix pseudostellariae. CONCLUSION:The decoction of radix pseudostellariae ameliorates cardiac functions of rat with chronic heart failure. The mechanism maybe involves in the inhibition of the MMP-2 and MMP-9 mRNA expression and activities in cardiac ventricles. 相似文献
147.
本文通过工程实例说明如何将大型地下商场的空调、通风及防排烟系统三者结合在一起,用一套风系统来实现其各自作用的。 相似文献
148.
Hu Q Pan Z Deen S Meng S Zhang X Zhang X Jiao XA 《Veterinary immunology and immunopathology》2007,120(3-4):223-233
Chinese native chicken breeds provide useful resources for the study of genetic diversity. In this study, the alleles of CD8 alpha and CD3d cDNA from Chinese native and introduced western breeds of chicken were analyzed at the sequence level. Six alleles were found, due to 13 amino acid replacements in the extracellular domain of the CD8 alpha sequence. There were four alleles detected in the Chinese strains, and alleles 5 and 6 were identified for the first time. Allele 6 was shared by Langshan, Beijing Fatty and Recessive White Feather chickens. Allele 2, found in the Bigbone strain, was the same as that found in the Leghorn strain H.B15.H7, and allele 3 in the Xianju breed was also the same as in the Leghorn strain H.B15.H12. Two Leghorn lines (RPL line 7 and AY519197) and the Camellia possessed an allele (alleles 1, 4 and 5), respectively, that was not found in the other lines. Nine out of 13 amino acid replacements were situated in the putative major histocompatibility complex (MHC) class I binding CDR1 (positions 30, 33 and 34), CDR2 (positions 58, 62, 63 and 65) and CDR3 (positions 90 and 106). Except for the Xianju breed, the CD8 alpha cDNA of Chinese native chicken breeds shared high homology. Two alleles were found in CD3d. Three additional nucleotides were found at positions 64, 65 and 66 in the newly discovered allele 2. This led to a difference of four amino acids (at residues 22, 23, 24 and 25) in the extracellular domain of CD3d cDNA from the Gushi, Recessive White Feather and ISA chickens compared with these of the White Leghorn and T11.15 (NM_205512). Five hybridoma clones (1C9, 1H5, 4B11, 6G5 and 13C5) against chicken CD8 alpha were generated by DNA immunization. Two monoclonal antibodies (mAbs), 6G5 and 4B11, showed reactivity to the splenocytes from five Chinese native chicken breeds, the Recessive White Feather chicken and the Leghorn (AY519197), while mAbs 1C9, 1H5 and 13C5 showed no reaction with these breeds. 相似文献
149.
以抗旱力弱的毛果绣线菊与抗旱力强的华北绣线菊为试验材料,采用不同程度干旱处理,在测定其光合作用变化的基础上,采用蛋白质组学技术研究两种绣线菊光合作用相关蛋白表达的变化。结果表明:干旱胁迫两种绣线菊光合能力降低,光补偿点和光饱和点降低,说明利用弱光能力提高,华北绣线菊适应弱光环境的能力强于毛果绣线菊。不同水平干旱处理分别鉴定出涉及能量代谢与运输的相关蛋白20种。干旱胁迫下毛果绣线菊中卡尔文循环途径相关酶、光系统Ⅱ中多数放氧复合蛋白和捕光色素复合蛋白、参与光合磷酸化的酶发生显著上调和下调表达;华北绣线菊中参与卡尔文循环代谢相关酶、PSⅠ中反应中心蛋白和参与光合电子传递的蛋白、PSⅡ中捕光色素复合蛋白、参与光合磷酸化与氧化磷酸化的蛋白发生明显的上调和下调表达。干旱胁迫使抗旱力不同的毛果绣线菊和华北绣线菊光合作用相关蛋白均受到影响,毛果绣线菊中多是能量代谢相关蛋白发生显著变化,华北绣线菊中多是能量运输相关蛋白发生显著变化。 相似文献
150.