铜在狐尾藻中的积累及亚细胞分布和化学形态

为探索狐尾藻对重金属铜的积累和耐性机制,本研究通过水培试验,研究不同浓度铜处理（0、20、50 mg·L^-1）对狐尾藻（Myriophyllum spicatum L.）生长生理特性以及叶片表皮细胞形态的影响,分析各器官中铜吸收转运及铜在各组织器官亚细胞中的分布和化学形态。结果表明：各浓度铜处理下狐尾藻均能存活,但铜浓度高于50 mg·L^-1时,狐尾藻根、茎、叶生物量相比对照（铜 0 mg·L^-1）处理降低53.48%、36.99%和32.22%。铜处理后,狐尾藻根、茎和叶铜含量分别为11.81~186.34、1.32~7.89、2.11~11.99 mg·kg^-1,根系中铜含量均高于叶片和茎部。铜在狐尾藻中的亚细胞分布主要位于根、茎、叶的细胞壁部分（36.49%~49.61%、45.44%~49.92%、41.45%~55.92%）,其次是可溶性组分（21.65%~25.99%、23.03%~27.65%、18.01%~34.63%）。狐尾藻中铜的赋存化学形态以盐酸提取态、醋酸提取态和乙醇提取态为主,所占比例为76.34%~86.67%,均是活性较低的形态。因此,狐尾藻是铜富集较好的植物,其根部的耐性大于茎、叶。铜以吸附态或蛋白质、果胶酸盐等低活性形态赋存于细胞壁或可溶性组分（液泡）中是狐尾藻积累和耐受铜的重要机制。     

长期饲喂高锌日粮对断奶仔猪免疫机能的影响

试验选用60头23日龄±1日龄临床检查健康的"杜×长×大"三元杂交断奶仔猪,按体重和性别随机分成3组,每组20头,分别饲喂基础日粮、基础日粮 3000mg/kg氧化锌、基础日粮 500mg/kg蛋氨酸锌,测定断奶仔猪免疫机能的变化。结果显示,在断奶后0d～21d饲喂高锌日粮能显著提高仔猪白细胞吞噬率和T淋巴细胞转化率,增加血清免疫球蛋白水平;而在断奶后42d、70d,仔猪白细胞吞噬率、T淋巴细胞转化和血清IgG、IgA水平显著下降。     

微囊藻毒素-LR对生菜非结构性碳水化合物代谢的影响

【目的】研究低质量浓度微囊藻毒素-LR（MC-LR）慢性暴露对生菜（Lactuca sativa）叶片及根系非结构性碳水化合物代谢的影响,为富营养化水体在生菜灌溉中的应用提供理论指导。【方法】以散叶生菜为试验材料,采用土培试验方法,设置不同质量浓度（0（对照组）,1,5,10,30 μg/L）MC-LR的水溶液灌溉生菜30 d,通过分析生菜叶片及根系中可溶性糖（葡萄糖、果糖和蔗糖）及淀粉含量、蔗糖和淀粉代谢相关酶活性的变化,探讨生菜非结构性碳水化合物代谢对MC-LR慢性暴露的响应。【结果】10和30 μg/L MC-LR组生菜对MC-LR的富集系数较5 μg/L MC-LR组分别显著上升10.85%和17.83%（P＜0.05）,而对MC-LR的转运系数分别显著下降17.46%和13.85%（P＜0.05）。与对照组相比,1 μg/L MC-LR组生菜净光合速率显著提高了9.17%（P＜0.05）,叶片中果糖含量及根系中葡萄糖含量和淀粉酶（AMS）活性分别显著增加了52.71%,19.13%和37.01%（P＜0.05）;5,10和30 μg/L MC-LR组生菜净光合速率提高,但差异不显著（P＞0.05）,叶片和根系中葡萄糖、果糖和蔗糖含量均显著增加（P＜0.05）,叶片中性转化酶（NI）活性分别显著降低了27.10%,38.01%和37.29%（P＜0.05）,淀粉合成酶活性分别显著增加20.92%,24.57%和30.28%（P＜0.05）,根系蔗糖合成酶、蔗糖磷酸合成酶（SPS）和AMS活性均显著增加（P＜0.05）。【结论】1 μg/L MC-LR水溶液灌溉对生菜叶片和根系中非结构性碳水化合物的分布和代谢影响较弱;而5～30 μg/L MC-LR水溶液灌溉通过促进生菜根系淀粉分解和蔗糖代谢活性,维持体内较高浓度的可溶性糖,从而提高生菜的抗逆性。     

脱氢枞胺水杨醛类席夫碱(Schiff Bases)对铜离子萃取性能的研究

合成5种脱氢枞胺水杨醛类Schiff碱,对其萃取铜离子的影响因素进行研究,并与萃取剂N902对电镀废水中铜离子的萃取性能进行了比较.结果表明:萃取温度和萃取时间对铜离子萃取率的影响不明显,萃取温度在20～30 ℃、萃取时间为2 h就能达到萃取平衡;大部分Schiff碱在低pH范围内对铜离子的萃取效果不理想,在高pH范围内有较好的萃取性能.DHAA 2,3,4-三羟基苯甲醛的萃取效果与N902相当.     

不同水平铜对小鼠营养与免疫功能的影响

试验选用19～20日龄昆明普通级小鼠108只,低铜饲养20d后,随机分成3组,每组设3个重复,每重复4只。1组饲喂以大豆分离蛋白-玉米淀粉为主的基础饲粮作为对照;2、3组饲粮中分别加入4.5mg/kg和45mg/kg的硫酸铜以铜计,测定小鼠组织器官中铜浓度及部分免疫学指标,以研究不同水平铜对小鼠营养和免疫功能的影响。     

Mesh-like vascular changes in copper deficiency-induced rat cardiomyopathy

The pathological effects of copper deficiency (COD) are well known. However, the pathogenesis of cardiomyopathy resulting from COD remains unclear. In this study, aimed to elucidate the pathogenesis of COD-induced cardiomyopathy by examining the morphology of the cardiovascular system in copper-deficient rats using histopathology, immunohistochemistry, and scanning and transmission electron microscopy. Changes detected in the myocardium and interstitium were consistent with those reported for COD. Morphological changes included mesh-like changes in the capillary endothelial cells that appear to be a novel finding in COD-induced cardiomyopathy. These changes are hypothesized to result from abnormal vascular remodeling following damage to the basement membrane and due to the mechanical effects of myocardial contractions. Although cardiomyopathy may be associated with microcirculatory disorders arising from these lesions, further investigations are necessary to demonstrate a causal relationship between the pathogenesis of cardiomyopathy and the contribution of these lesions to disease progression.     

钼和铜对雏鸡肾脏抗氧化能力的影响

为研究饲料中不同剂量钼和铜对雏鸡肾的影响,试验用2日龄海兰褐壳蛋公雏鸡80只,随机平均分为Ⅰ空白对照组、Ⅱ(Cu 800 mg/kg,Mo 400 mg/kg)、Ⅲ(Cu 800 mg/kg,200 mg/kg)、Ⅳ(Cu 800mg/kg,100mg/kg)组。试验60d,每15d每组随机处死5只测定肾脏总超氧化物岐化酶(T-SOD)、过氧化物酶(POD)、黄嘌呤氧化酶(XOD)、谷胱甘肽过氧化物酶(GSH-Px)含量。结果表明,试验组T-SOD第15天最高,随后呈下降趋势(P0.05);POD、GSH-Px和XOD随时间延长呈上升趋势(P0.05),Ⅲ组GSHPx第30天时最高,最后回归正常,Ⅱ组XOD第30天最高,Ⅲ组POD随时间延长先下降后上升(P0.05),第45天时最高,Ⅳ组POD随时间延长先下降后上升再下降(P0.05)。说明日粮中以2∶1的比例关系添加Cu 800mg/kg、Mo 400mg/kg,随时间的延长可提高肾脏抗氧化能力。     

粉煤灰磁粉表面化学镀铜的研究

粉煤灰磁粉是热电厂生产过程产生的固体废弃物粉煤灰中的一种成分,由于其有内在的磁性和微导电性,通过表面金属化后,能用于制备电磁屏蔽和吸波材料。笔者采用置换反应法在粉煤灰空心磁粉表面进行了化学镀铜的研究。扫描电镜(SEM)和能谱(EDX)分析结果表明,该化学镀方法能在其表面获得良好性能的金属镀层。     

Mineral absorption in the black rhinoceros (Diceros bicornis) as compared with the domestic horse

To test whether mineral recommendations for horses are likely to guarantee adequate mineral provision for black rhinoceroses (Diceros bicornis), we investigated the apparent absorption (aA) of macro- and microminerals in eight black rhinoceroses from three zoological institutions in a total of 32 feeding trials with total faecal collection, with additional data from three unpublished studies (18 feeding trials). Feeds and faeces were analysed for Ca, P, Mg, Na, K, Fe, Mn, Cu, Zn and Co. The resulting aA coefficients, and the linear relationships of apparently absorbable dietary mineral content to total dietary mineral content [per 100 g dry matter (DM)], were compared with data for domestic horses. Rhinoceroses had significantly higher aA coefficients for Ca and Mg (because of a higher calculated 'true' absorption), and lower ones for Na and K (because of calculated higher endogenous faecal losses). High absorption efficiency for divalent cations is hypothesized to be an adaptation to a natural diet of particularly high Ca:P ratio (approximately 14:1); an effective removal of Ca from the ingesta guarantees sufficient P availability at the fermentation site in the hindgut. Higher faecal losses of Na and K are hypothesized to be linked to a higher faecal bulk per DM intake in black rhinoceroses as compared with horses because of a generally lower digestive efficiency. There were no relevant differences in the absorption patterns of microminerals. In particular, there were no discernable differences in Fe absorption within the rhinoceroses for diets with and without tannin supplementation. Several of the zoo diets assessed in this study were deficient in Cu, Mn or Zn, and most contained excessive levels of Fe when compared with horse requirements. The findings of this study indicate that differences in mineral absorption between occur even between species of similar digestive anatomy; that in particular, Ca absorption might vary between hindgut fermenters with Ca:P ratio in their natural diet; that Na might be a particularly limiting factor in the ecology of free-ranging rhinoceroses; that moderate doses of tannins do not seem to markedly influence mineral absorption; and that diets for captive animals should contain adequate, but not excessive mineral levels.