佛山市某工业区周边蔬菜地土壤重金属含量与评价

采集并分析测试佛山市某工业区周边蔬菜地土壤.研究土壤Zn、Cu、Pb和Cd的含量和分布特征,按照国家土壤环境质量二级标准对其现状进行评价;并采用连续提取的方法分析了表层土壤Zn、Cu、Pb和Cd的化学形态分布.结果表明,研究区域20%的土壤样品受到重金属轻度污染,污染因子主要为Cd.土壤中Zn和Cu以残渣态所占比例最高,Pb和Cd分别以铁锰氧化物结合态和酸可提取态所占的比例最高,Zn、Cu、Pb和Cd非残渣态所占比例随着全量的增加而增加,Zn、Cu、Pb和Cd迁移能力依次为Cd>Zn>Cu>Pb.人类活动已导致该工业区周边农业土壤中Zn、Cu、Pb和Cd的明显积累,且土壤重金属明显向深层迁移.     

牛红细胞生成性卟啉症的研究进展

EPP是一种常染色体隐性遗传缺陷病。由亚铁螯合酶基因缺陷导致编码酶的活性降低引起,该酶活性不足时使动物体内血红素含量降低和卟啉及其前体过度增加。文章就牛、人EPP的主要症状、检测方法、亚铁螯合酶及其基因的研究进展进行较为详细的论述。     

内蒙古典型草原区植被动态与植被恢复——以锡林郭勒盟典型草原区为例

内蒙古草原植被是一个极脆弱的生态系统,易受干旱等自然灾害影响。自1999年以来,全区大部分地区连续三年干旱和虫害(蝗灾),造成严重的草原退化和沙化。2002年后,内蒙古天然植被整体上有不同程度好转,草原生态环境有所改善。本文以锡林郭勒1999至2004年MODIS和TM影象数据和地面样点数据为依据,从宏观和微观两方面揭示了锡林郭勒草地植被动态规律和变化趋势,并系统分析了草地植被发生的变化原因、驱动因素和机理,阐明了锡林郭勒盟典型区草地所面临的问题,以期为我区草原植被恢复应采取的对策和措施提供依据。     

Effect of NOS on podocytes in hyperlipidemia rats and the protection of simvastatin in podocyte damage

AIM: To investigate the possible effect of hyperlipidemia on golmerular podocytes,the nitric oxide synthase (NOS) availability and the synthesis of NOS in podocyte damage by hyperlipidemia,further to study the protective effect of simvastatin on podocytes.METHODS: 4 groups of Wistar rats were fed high fat diet for 18 weeks.Serum lipid,urinary protein excretion and renal pathological changes were detected.Immunohistochemistry was used to determine the expression of desmin.The expression of nNOS was detected by Western blotting.RESULTS: The level of serum lipid was increased significantly in hyperlipidemic group and treated group after 4 weeks (P<0.01) and was decreased significantly in simvastatin treated group compared with hyperlipidemic group (P<0.01).Podocyte injury was detected under electronic microscopy in hyperlipidemic group after 4 weeks,and the injury became more serious during the lasting time.The expression of desmin was increased in hyperlipidemic group after 4 weeks,and the level was significantly decreased in treated groups (P<0.01).The urinary protein excretion was increased significantly after 6 weeks (P<0.01),and the level was significantly lower in treated groups (P<0.01).The expression of nNOS was significantly decreased in hyperlipidemic and treated groups (P<0.01),and the level significantly decreased in simvastatin group (P<0.01).CONCLUSION: Hyperlipidemia induces podocyte injury.The injury seems to be associated with NO deficiency and decreased renal NOS activity.The injury can be relieved by simvastatin.     

广西罗非鱼和卵形鲳鲹海豚链球菌的生化特性及基因多态性分析

对2006-2011年从广西养殖的罗非鱼Oreochromis niloticus和卵形鲳鲹Trachinotus ovatus中分离的链球菌菌株进行生理生化和二重PCR鉴定,并利用随机扩增多态性DNA标记( RAPD)对经鉴定为海豚链球菌Streptococcus iniae的临床菌株进行生化特性及基因多态性分析。结果表明：经鉴定共有22株临床分离菌株为海豚链球菌; RAPD分析发现,所有菌株的电泳结果均在750 bp处出现特异性条带,且带型相同;结合Bachrach的研究结果,推测本试验中所分离的22株海豚链球菌的血清型均为Ⅰ型。本研究结果可为防治鱼类海豚链球菌病提供科学依据。     

广西发展稻田、桑田晚秋和宿根蔗地早春马铃薯探讨

从气候条件、土地资源和市场空间等方面分析了广西发展稻田、桑田晚秋及宿根蔗地早春马铃薯的可行性,提出要科学配置已有资源,合理安排各地空闲稻田、桑田晚秋和冬种马铃薯以及宿根越冬甘蔗地早春马铃薯的种植与布局,形成一个符合广西实际的、合理的、不与其他粮食和经济作物争地的马铃薯种植新格局。     

生长调节剂在暖季型草坪中的研究应用

近年来,植物生长调节剂在草业中的研究应用已经成为草业工作者研究的一大热点.植物生长调节剂被广泛地研究应用于调节暖季型草坪草的营养生长、改善草坪质量、增强暖季型草坪草的抗逆性以及提高其种子的产量等方面,并且取得了一定成果.     

萝卜与苤蓝属间杂种胚离体培养…

以萝卜雄性不育系DH303A为母本,以苤蓝为父本进行属间远缘杂交,萝卜与苤蓝杂交的不亲和性发生在胚珠发育过程中,杂交荚荚长快速生长期在授粉后的第2~5天,而横径快速生长期在授粉后第2~4天。在杂种胚发育后第6天和第7天进行胚抢救,用诱导培养基:MS+2,4-D 2.0 mg/L+KT 0.5 mg/L+蔗糖3%+琼脂0.6%;继代培养基:MS+2,4-D 2.0 mg/L+KT 0.5 mg/L+蔗糖3%+琼脂0.6%;分化培养基:MS+IAA 0.5 mg/L+KT 1.5 mg/L+蔗糖3%+琼脂0.6%;生根培养基:MS+NAA 0.2 mg/L+IAA 0.5 mg/L+蔗糖3%+琼脂0.6%,能成功获得幼苗。     

Analysis of Nitrite Accumulation During Denitrification

To realize the purpose of enhanced nitrogen removal (TN<5 mg·L-1) in step feed process treating urban wastewater, by using SBR reactor, the nitrite accumulation, variation of pH and ORP as well as dynamic properties during denitrification with methanol and glucose as the sole carbon sources are investigated in details. The results show that for both carbon sources, serious nitrite accumulations are observed during denitrification under different ratios of nitrogen and carbon (C/N). With identical C/N, when glucose is used as carbon source there is more maximum NO2--N accumulation concentration. However, NO3--N reduction rate is faster than NO2--N reduction rate for both carbon sources. Furthermore, with the increase of C/N, the maximum NO2--N concentration increases and the time in which the NO2--N achieves the highest concentration is accordingly shortened. For glucose, however, under high C/N ratio (C/N=29.3) both the denitrification rate and NO2--N accumulation concentration decrease. Besides, the changes of pH and ORP reflect the variation of NO2--N accumulation concentration well because pH and ORP have the significant relationship with NO2--N concentration. The second inflexion on curves indicates the real end of denitrification process.