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991.
城郊公路两侧主要森林类型铅含量及分布规律 总被引:31,自引:3,他引:28
对南京城郊312国道两侧主要森林类型林木不同器官中Pb含量和分布规律的研究表明,不同树种、同一树种不同器官中Pb含量有明显差异.火炬松对Pb污染的净化能力强于杉木、栎树.汽车尾气排放的Pb污染影响范围在离公路两侧100m以内,主要在40m以内范围.有林地土壤由于有林木及林下植被的覆盖,其Pb含量(尤其是表层0~20cm范围内)明显降低,说明林分可有效地降低土壤中Pb的污染程度.林木不同器官对Pb尘的吸附率在180%~281%之间,以叶片吸附能力最强;不同树种比较,以松树吸附率为高 相似文献
992.
金属硫蛋白(metalothionein,简称MT)是一类低分子量、富含半胱氨酸的蛋白质,由于1个MT分子可结合7个金属离子,因此MT分子具有很强的金属结合特性[1,2].本文一方面利用MT分子的高金属结合性能,另一方面利用苏州医学院血液研究所研制成... 相似文献
993.
Y Wang Z S Zhang J S Ruan Y M Wang S M Ali 《Journal of industrial microbiology & biotechnology》1999,23(3):178-187
Five thousand actinomycetes were isolated from soil samples collected from rainforests in Singapore and the generic identities
of these isolates were determined by using a procedure that combined morphological, chemotaxonomic and 16S rDNA sequence-based
phylogenetic analyses. Actinomycetes belonging to a total of 36 genera were identified. The most abundant isolates are members
of Streptomyces, Micromonospora, Actinoplanes, Actinomadura, Nonomuria, Nocardia and Streptosporangium. By phylogenetic analysis of 16S rDNA sequences of our isolates together with those of known actinomycete species, we also
evaluated the species diversity of several genera including Streptomyces, Micromonospora, Nonomuria, and Actinomadura. We found that: first, the tropical isolates are present in most clades represented by known species; and second, many tropical
isolates form new clades distant from the known species, indicating the presence of unidentified taxa at both species and
genus levels. Based on these results, we conclude that actinomycete diversity in the tropical rainforest is very great and
should represent an excellent source for discovery of novel bioactive compounds.
Received 17 March 1999/ Accepted in revised form 24 June 1999 相似文献
994.
枯否细胞在实验性肝癌细胞凋亡中的作用研究 总被引:1,自引:0,他引:1
探讨Kupffer细胞在大鼠实验性肝癌细胞凋亡中的作用。应用免疫组化方法和TUNEL法对单用二乙基亚硝胺(DENA)诱发的肝癌及用氯化钆(GC)或酶母多糖(ZM)分别阻塞或激活Kupffer细胞后,给以DENA所引起的大鼠肝癌中的增殖细胞核抗原(PCNA)、bax、bcl-2蛋白表达和肝癌细胞的凋亡进行了对比研究,结果显示:肝癌组织的增殖指数在ZM+DENA组、DENA组、GC+DENA组依次增高,而凋亡指数在上述各组依次降低。Bax阳性率在ZM+DENA组明显高于DENA组(P<0.05),而ZM+DENA组bcl-2阳性率明显低于DENA组(P<0.05)。结果提示:Kupffer细胞可促进实验性肝部细胞凋亡。 相似文献
995.
Haochun Chen Hui Yao Xiangdong Ruan Bernard Wallner Julia Ostner Zuofu Xiang 《动物学报(英文版)》2021,67(4):465-467
Wildlife tourism is a thriving form of nature-based tourism that can provide revenue for conservation funds,and increase public aware-ness of biodiversity conse... 相似文献
996.
转录因子WRI1(WRINKLED 1)在油脂合成过程中发挥重要调控作用,其转录和翻译水平调控机理以及下游的靶基因现已基本明确,但尚未见其转录后调控的报道。为探讨沙棘(Hippophae rhamnoides) hrh-miRn458与转录因子WRI1之间的靶向关系,并阐明其在果肉和种子发育过程中的表达模式,通过生物信息学方法预测hrh-miRn458成熟体序列及其与候选靶基因WRI1的结合位点,采用双荧光素酶报告基因检测和RNApulldown技术相结合的方法验证hrh-miRn458与WRI1基因之间的靶向关系,并应用qRT-PCR方法分析hrh-miRn458与WRI1在沙棘不同发育期果肉和种子油脂合成过程中的表达变化。结果表明,生物信息学预测WRI1基因的CDS区第309–327位与hrh-miRn458成熟体序列的15个碱基互补;荧光检测显示pmirGLO-WRI1-WT+hrh-miRn458 mimics显著抑制荧光素酶活性(P<0.001); RNA pull down实验证实hrh-miRn458与WRI1存在互作关系;不同发育期果肉和种子中hrh-miRn45... 相似文献
997.
998.
999.
Jiliang Xu Xiaohui Zhang Zhengwang Zhang Guangmei Zheng Xiangfeng Ruan Keyin Zhang Bo Xi 《生物学前沿》2006,1(2):174-181
Home range and habitat use of male Reeves’s pheasant (Syrmaticus reevesii) were studied during winter of 2001~2002 and 2002~2003 in the Dongzhai National Nature Reserve, Henan Province. Results from five individuals of Reeves’s pheasant with over 30 relocations, indicated that the average size of home range was 10.03 ± 1.17 hm2 by Minimum Convex Polygon method, 8.60 ± 0.35 hm2 by 90% Harmonic Mean Transformation method, and 9.50 ± 1.90 hm2 by 95% Fixed Kernel method. It was observed that the winter range is smaller than that in the breeding season. The mean core area of the home range was found to be 1.88 ± 0.37 hm2. Although the habitat composition of the core area varied greatly for individuals, a large part of the habitats used were composed of confier and broadleaf mixed forests, masson pine forests, fir forests, and shrubs. Habitat use within the study area was non-random, while habitats within home ranges were randomly used. Habitat use was dictated by tree diameter at breast height, shrub height and coverage at 2.0 m. The proximity between forests and shrubs were also found to be important in providing refuge for the birds during winter. Recommendations for conservation management include protecting the existing habitats in Dongzhai National Nature Reserve, increasing suitable habitat for Reeves’s Pheasant through artificial plantations (e.g. firs), and restoring some parts of the large shrub area into forests. 相似文献
1000.
附子多糖FⅠ的分离纯化及部分理化性质研究 总被引:1,自引:0,他引:1
白附片经热水抽提、Sevag法脱蛋白、乙醇沉淀、DEAE-C32柱层析分离,再通过Sephadex G-200柱层析进一步纯化,得到一种纯白色粉末状多糖,糖含量为97%,平均分子量为2.6×105,熔点为270℃.经完全酸水解、薄层层析、红外光谱分析,证明为葡聚糖. 相似文献