谷氨酰胺对早期断奶仔猪血清中GPT、AKP、5′-NT的影响

研究了不同水平的谷氨酰胺对断奶仔猪血清中GPT、AKP、5′—NT活性的影响。试验证明,谷氨酰胺能够提高血清中酶的活性,缓解断奶给仔猪带来的应激,促进蛋白质的合成,还具有成骨作用。谷氨酰胺在断奶仔猪日粮中最适宜添加量为1.2%。     

Gln对早期断奶仔猪血清尿素氮含量和酶活性的影响

研究了谷氨酰胺对断奶仔猪血清中尿素氮和ALT、ALP、5'-NT活性的影响.试验选用80头平均体重为6.16±0.13kg的长白×约克夏二元杂交仔猪,28 1 d断奶后,按体重相近原则随机分为5个处理.谷氨酰胺的添加浓度分别为0%、0.3%、0.6%、0.9%和1.2%,试验全程21 d,分别于试验的第7、14和21d测定血清中各指标.结果表明,谷氨酰胺能够降低血清尿素氮含量,提高血清中酶的活性,其在断奶仔猪日粮中最适宜的添加量为1.2%.     

谷氨酰胺对断奶仔猪血清、肌肉指标和肌肉热休克蛋白表达的影响

为研究谷氨酰胺对断奶仔猪血清、肌肉生化指标和和肌肉热休克蛋白表达的影响,选用(28±1)d断奶的长白×大约克夏仔猪32头,随机分为2组,对照组饲喂基础日粮,谷氨酰胺组饲喂添加1.2%谷氨酰胺的基础日粮,试验期28d。试验结束采集仔猪血清和肌肉,测定血清和肌肉生化指标及肌肉中热休克蛋白表达情况。结果表明:仔猪日粮中添加谷氨酰胺有提高仔猪血清总蛋白、白蛋白、球蛋白,并降低了蛋白质系数的趋势(p0.05)。谷氨酰胺显著提高了肌肉谷胱甘肽(p0.05)和谷胱甘肽-S转移酶的含量(p0.05),显著降低了γ-L-谷氨酰转肽酶(p0.05)和丙二醛含量(p0.05),但对肌肉中超氧化物歧化酶活性影响不显著(p0.05)。同时,谷氨酰胺显著提高了肌肉中热休克蛋白70的阳性面积比和浓度。说明断奶仔猪日粮中添加1.2%谷氨酰胺促进了血清蛋白合成,并显著提高了肌肉的抗氧化能力和热休克蛋白的表达。     

谷氨酰胺对断奶应激仔猪大肠黏膜抗氧化性能和增殖细胞核抗原表达的影响

将40头(28±1)日龄的长白×约克夏断奶仔猪随机分为2组,每组设5个重复,分别饲喂基础日粮(对照组)、基础日粮+1.2%谷氨酰胺(谷氨酰胺组),研究日粮中添加谷氨酰胺对断奶仔猪大肠黏膜抗氧化性能和增殖细胞核抗原(PCNA)表达的影响。试验第7天,取仔猪大肠组织,测定其抗氧化指标和PCNA的表达情况。结果表明,谷氨酰胺组大肠黏膜的CAT活性、GSH和NO含量分别比对照组显著提高162.7%、8.3%和47.8%;日粮中添加谷氨酰胺降低了大肠黏膜MDA含量,但与对照组差异未达到显著水平;谷氨酰胺组大肠中PCNA蛋白阳性面积比显著高于对照组61.2%。可见,断奶仔猪日粮中添加1.2%谷氨酰胺能提高大肠黏膜的抗氧化性能,并对大肠黏膜细胞的增殖有一定促进作用。     

谷氨酰胺对早期断奶仔猪生长性能和免疫性能的影响

研究了不同水平的谷氨酰胺对断奶仔猪生产性能、免疫功能的影响。试验选用80头28±1d断奶、体重为6.16±0.13 kg的长白×约克夏仔猪,按单因素完全随机化设计随机分为5个处理,日粮中谷氨酰胺的添加量分别为0、0.3%、0.6%、0.9%和1.2%。试验期21 d。在断奶后7 d1、4 d2、1 d测定生产性能和淋巴细胞转化率,同时在断奶后7 d,每处理选4头仔猪免疫卵清白蛋白(OVA),于免疫前和免疫后第7天和第14天前腔静脉采血测定血清OVA抗体水平。结果表明:①随着谷氨酰胺添加量的增加,早期断奶仔猪日增重、日采食量提高(P≤0.05),料肉比下降(P>0.05);②谷氨酰胺能提高早期断奶仔猪淋巴细胞转化率和特异OVA抗体效价,提高仔猪的免疫性能;③综合生长性能与免疫性能,谷氨酰胺的最佳添加剂量为1.2%。     

甘氨酰谷氨酰胺二肽对断奶仔猪生长性能及血液激素水平的影响

将21日龄断奶仔猪40头随机分为4个组,每组3个重复,Ⅰ组为对照组,饲喂基础日粮.Ⅱ、Ⅲ、Ⅳ组在基础日粮的基础上分别添加w=0 50%谷氨酰胺、w=0 25%甘氨酰谷氨酰胺、w=0 50%甘氨酰谷氨酰胺.观察甘氨酰谷氨酰胺二肽对断奶仔猪生长性能和血液激素水平的影响.结果表明,添加w=0 25%和w=0 50%的甘氨酰谷氨酰胺组仔猪体质量、采食量和饲料转化率都有所提高,能降低断奶仔猪腹泻率,显著降低血液中皮质醇水平(P<0 05),血液中FT3和FT4水平各组差异不显著.提示断奶仔猪饲粮中添加甘氨酰谷氨酰胺二肽可提高仔猪的生长性能.     

谷氨酰胺对早期断奶仔猪小肠粘膜形态和抗氧化性能的影响

研究谷氨酰胺处理对断奶仔猪小肠粘膜形态变化和抗氧化作用的影响。试验选用40头(28±1)d断奶、体重均一的长白×约克夏仔猪,按单因素完全随机化设计随机分为2组,一组为对照组,喂基础日粮;一组为试验组,基础日粮添加1.2%的谷氨酰胺。在断奶后7d每个处理随机选取4头仔猪屠宰,取小肠组织,测定肠粘膜的形态变化和生化指标。结果表明:日粮中添加谷氨酰胺提高了小肠绒毛高度和固有层厚度,提高了GSH含量和CAT活性,降低了MDH含量,对肠粘膜起到了保护作用。     

中草药对断奶仔猪抗冷应激机能的影响

选用黄芪、红景天、当归3味中草药,对33日龄断奶仔猪在(14±1)℃条件下进行了慢性冷应激(5 d)试验,通过测试仔猪的血清中NO含量、谷胱甘肽过氧化物酶(GSH-PX)活性、红细胞和白细胞数量等指标来探索中草药对冷应激断奶仔猪抗氧化功能和生理机能的作用。结果表明,与对照组相比,1%当归组和1%红景天组断奶仔猪血清中NO含量、GSH-Px活性、红细胞及白细胞数量变化差异不显著(p0.05);1%黄芪组断奶仔猪血清中NO含量极显著下降(p0.01),而GSH-Px活性、红细胞及白细胞数量极显著升高(p0.01),说明黄芪可使冷应激引起的NO含量、GSH-PX活性明显发生变化,具有抗氧化功能和生理机能促进作用。     

早期断奶及谷氨酰胺添加对仔猪血清游离氨基酸及其代谢产物的影响

为研究早期断奶及谷氨酰胺添加对仔猪血清游离氨基酸及其代谢产物的影响。分别选取哺乳、断奶和饲喂谷氨酰胺的小母猪用于试验,采用色谱分析、主成分分析、偏最小二乘法判别分析等方法,对仔猪的生长性能、氨基酸含量进行分析。结果发现,血清游离氨基酸中,断奶组的精氨酸、组氨酸、缬氨酸、半胱氨酸、脯氨酸、丝氨酸和酪氨酸含量较哺乳组含量显著降低(P<0.05),断奶组的异亮氨酸、蛋氨酸、苯甲基丙氨酸、苏氨酸和丙氨酸含量较哺乳组含量显著上升(P<0.05);谷氨酰胺组的苏氨酸和甘氨酸含量较断奶组含量显著降低(P<0.05),谷氨酰胺组的亮氨酸、异亮氨酸、半胱氨酸和缬氨酸含量较断奶组含量显著上升(P<0.05);氨基酸代谢产物中,断奶组的γ-氨基正丁酸、牛磺酸、瓜氨酸、肌肽、乙醇胺和羟赖氨酸含量较哺乳组含量显著降低(P<0.05),断奶组的α-氨基己二酸、胱硫醚、鹅肌肽、1-甲基组氨酸、3-甲基组氨酸、磷酸乙醇胺、磷酸丝氨酸和尿素含量较哺乳组含量显著上升(P<0.05);谷氨酰胺组的鸟氨酸、鹅肌肽和磷酸乙醇胺含量较断奶组含量显著降低(P<0.05),谷氨酰胺组的α-氨...     

高铜日粮对早期断奶应激仔猪生长性能和抗氧化酶活性的影响

选用"长大定"三元杂交断奶仔猪研究高铜日粮对早期断奶应激仔猪生长性能和抗氧化酶活性的影响,于断奶后称重并计算采食量,观察断奶后腹泻情况,同时于前腔静脉采血,测定血清铜锌超氧化物歧化酶(CuZn-SOD)和血清铜蓝蛋白(CP)活性.结果表明,高铜日粮能显著提高断奶应激仔猪体重、日增重和日采食量,降低料重比和断奶后腹泻率,提高血清超氧化物歧化酶(CuZn-SOD)和血清铜蓝蛋白(CP)活性.     

Hotspots, basalts, and the evolution of the mantle

The trace element concentration patterns of continental and ocean island basalts and of mid-ocean ridge basalts are complementary. The relative sizes of the source regions for these fundamentally different basalt types can be estimated from the trace element enrichment-depletion patterns. Their combined volume occupies most of the mantle above the 670 kilometer discontinuity. The source regions separated as a result of early mantle differentiation and crystal fractionation from the resulting melt. The mid-ocean ridge basalts source evolved from an eclogite cumulate that lost its late-stage enriched fluids at various times to the shallower mantle and continental crust. The mid-ocean ridge basalts source is rich in garnet and clinopyroxene, whereas the continental and ocean island basalt source is a garnet peridotite that has experienced secondary enrichment. These relationships are consistent with the evolution of a terrestrial magma ocean.     

Climate change, deforestation, and the fate of the Amazon

The forest biome of Amazonia is one of Earth's greatest biological treasures and a major component of the Earth system. This century, it faces the dual threats of deforestation and stress from climate change. Here, we summarize some of the latest findings and thinking on these threats, explore the consequences for the forest ecosystem and its human residents, and outline options for the future of Amazonia. We also discuss the implications of new proposals to finance preservation of Amazonian forests.     

Diamonds, Eclogites, and the Oxidation State of the Earth's Mantle

The reaction dolomite + 2 coesite --><-- diopside + 2 diamond + 2O(2) defines the coexistence of diamond and carbonate in mantle eclogites. The oxygen fugacity of this reaction is approximately 1 log unit higher at a given temperature and pressure than the oxygen fugacities of the analogous reactions that govern the stability of diamond in peridotite. This difference allows diamond-bearing eclogite to coexist with peridotite containing carbonate or carbonate + diamond. This potential coexistence of diamond-bearing eclogite and carbonate-bearing peridotite can explain the presence of carbon-free peridotite interlayered with garnet pyroxenites that contain graphitized diamond in the Moroccan Beni Bousera massif at the Earth's surface and the preferential preservation of diamond-bearing eclogitic relative to peridotitic xenoliths in the Roberts Victor kimberlite.     

Pre-Columbian urbanism, anthropogenic landscapes, and the future of the Amazon

The archaeology of pre-Columbian polities in the Amazon River basin forces a reconsideration of early urbanism and long-term change in tropical forest landscapes. We describe settlement and land-use patterns of complex societies on the eve of European contact (after 1492) in the Upper Xingu region of the Brazilian Amazon. These societies were organized in articulated clusters, representing small independent polities, within a regional peer polity. These patterns constitute a "galactic" form of prehistoric urbanism, sharing features with small-scale urban polities in other areas. Understanding long-term change in coupled human-environment systems relating to these societies has implications for conservation and sustainable development, notably to control ecological degradation and maintain regional biodiversity.     

Oxytocin, vasopressin, and the neurogenetics of sociality

There is growing evidence that the neuropeptides oxytocin and vasopressin modulate complex social behavior and social cognition. These ancient neuropeptides display a marked conservation in gene structure and expression, yet diversity in the genetic regulation of their receptors seems to underlie natural variation in social behavior, both between and within species. Human studies are beginning to explore the roles of these neuropeptides in social cognition and behavior and suggest that variation in the genes encoding their receptors may contribute to variation in human social behavior by altering brain function. Understanding the neurobiology and neurogenetics of social cognition and behavior has important implications, both clinically and for society.