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991.
深圳市宝安区蔬菜农药残留研究 总被引:2,自引:0,他引:2
根据2006年、2007年和2008年对55种蔬菜、共27551份样品农药残留的检测结果,分析了广东深圳市宝安地区蔬菜农药残留的状况和规律.结果表明:随着政府各项监督管理措施的落实,宝安地区蔬菜农药残留超标率逐年下降,2006年为4.35%,2007年为4.34%,2008年为1.41%;每年6~8月超标率最低,而冬春两季超标率较高;检出超标率最高的农药是有机磷类农药,包括甲基异柳磷、治螟磷、毒死蜱和敌敌畏,其次是氯氰菊酯和甲氰菊酯等拟除虫菊酯类农药;在抽检的55种蔬菜中超标率较高的是几种十字花科蔬菜,依次是芥菜、小白菜和菜心. 相似文献
992.
Lu Huang Xiaojie Cheng Chengsheng Liu Ke Xing Jing Zhang Gangzheng Sun Xiaoyan Li Xiguang Chen 《生物学前沿》2009,4(3):321-327
An oleic acid-grafted chitosan oligosaccharide (CSO-OA) with different degrees of amino substitution (DSs) was synthesized by the 1-ethyl-3-(3-dimethylami-nopropyl) carbodiimide (EDC)-mediated coupling reac-tion. Fourier transform infrared spectroscopy (FT-IR) suggested the formation of an amide linkage between amino groups of chitosan oligosaccharide and carboxyl groups of oleic acid. The critical aggregation concentra-tions (CACs) of CSO-OA with 6%, 11%, and 21% DSs were 0.056, 0.042, and 0.028mg·mL-1, respectively. Nanoparticles prepared with the sonication method were characterized by means of transmission electron micro-scopy (TEM) and Zetasizer, and the antibacterial activity against Escherichia coli and Staphylococcus aureus was investigated. The results showed that the CSO-OA nanoparticles were in the range of 60-200 nm with satisfactory structural integrity. The particle size slightly decreased with the increase of DS of CSO-OA. The antibacterial trial showed that the nanoparticles had good antibacterial activity against E. coli and S. aureus. 相似文献
993.
Background
Microarray technology is commonly used as a simple screening tool with a focus on selecting genes that exhibit extremely large differential expressions between different phenotypes. It lacks the ability to select genes that change their relationships with other genes in different biological conditions (differentially correlated genes). We intend to enrich the above procedure by proposing a nonparametric selection procedure that selects differentially correlated genes. 相似文献994.
Identification and characterization of novel amphioxus microRNAs by Solexa sequencing 总被引:1,自引:0,他引:1
995.
Bo Zhao Erica K Benson Ruifang Qiao Xing Wang Sunchin Kim James J Manfredi Sam W Lee Stuart A Aaronson 《EMBO reports》2009,10(1):71-78
Ku80 is important in the repair of DNA double-strand breaks by its essential function in non-homologous end-joining. The absence of Ku80 causes the accumulation of DNA damage and leads to premature ageing in mice. We showed that mouse embryonic fibroblasts (MEFs) from ku80−/− mice senesced rapidly with elevated levels of p53 and p21. Deletion of p21 delayed the early senescence phenotype in ku80−/− MEFs, despite an otherwise intact response of p53. In contrast to ku80−/−p53−/− mice, which die rapidly primarily from lymphomas, there was no significant increase in tumorigenesis in ku80−/−p21−/− mice. However, ku80−/−p21−/− mice showed no improvement with respect to rough fur coat or osteopaenia, and even showed a shortened lifespan compared with ku80−/− mice. These results show that the increased lifespan of ku80−/− MEFs owing to the loss of p21 is not associated with an improvement of the premature ageing phenotypes of ku80−/− mice observed at the organismal level. 相似文献
996.
Hai Jin He Xing Sheng Wang Rong Pan Liang Dong Wang Ming Nan Liu Rong Qiao He 《BMC cell biology》2009,10(1):81
Background
The microtubule-associated protein tau is able to interact with actin and serves as a cross-linker between the microtubule and actin networks. The microtubule-binding domain of tau is known to be involved in its interaction with actin. Here, we address the question of whether the other domains of tau also interact with actin. 相似文献997.
Xing Fan Li-Na Sha Rui-Wu Yang Hai-Qin Zhang Hou-Yang Kang Cun-Bang Ding Li Zhang You-Liang Zheng Yong-Hong Zhou 《BMC evolutionary biology》2009,9(1):247-15
Background
Single- and low- copy genes are less likely subject to concerted evolution, thus making themselves ideal tools for studying the origin and evolution of polyploid taxa. Leymus is a polyploid genus with a diverse array of morphology, ecology and distribution in Triticeae. The genomic constitution of Leymus was assigned as NsXm, where Ns was presumed to be originated from Psathyrostachys, while Xm represented a genome of unknown origin. In addition, little is known about the evolutionary history of Leymus. Here, we investigate the phylogenetic relationship, genome donor, and evolutionary history of Leymus based on a single-copy nuclear Acc1 gene. 相似文献998.
It is still an open question that how the teeth root development is initiated at the molecular level. But what we know is that the teeth root development begins after the crown part is completely formed, and then the terminal cervical loop structure faces two developmental fate options when the crown development is quite advanced: it can remain as a ‘crown’ pattern, and continue enamel production, or it can adopt the ‘root’ fate, and begins teeth root development. Epithelial notch and mesenchymal fgf10 signaling are thought to be the key switches of root or crown development pattern. But, for a rodent's molars and incisors, it is very interesting that after a similar teeth crown developmental process, the late development for the molars and incisors is quite different: the molar germ forms a multi-rooted pattern, while the incisor germ forms a single-rooted analogue and without a really root development process. In a recent study, one of the negative regulating factors for notch signaling, sel1l was found strongly related to the molar root development. So we hypotheses that the negative regulating factors of notch signaling, may be the key signals to determine the tooth root developmental onset, and the quantity or function's abnormal of that factors, may lead to hypoplasia of the teeth root. 相似文献
999.
The tissue-preferential distributed calcium sensors, SOS3 and SCaBP8, play important roles in SOS pathway to cope with saline conditions. Both SOS3 and SCaBP8 interact with and activate SOS2. However the regulatory mechanism for SOS2 activation and membrane recruitment by SCaBP8 differs from SOS3. SCaBP8 is phosphorylated by SOS2 at plasma membrane (PM) under salt stress. This phosphorylation anchors the SCaBP8-SOS2 complex on plasma membrane and activates PM Na+/H+ anti-porter, such as SOS1. Here, we describe that SOS2 has high binding affinity and catalytic efficiency to SCaBP8, suggesting that phosphorylation of SCaBP8 by SOS2 perhaps occurs rapidly in salt condition. SCaBP8 is also phosphorylated by PKS5 (SOS2-like Protein Kinase5) which negatively regulates PM H+-ATPase activity and functions in plant alkaline tolerance, providing a clue to roles of SCaBP8 in both salt and alkaline tolerance. SOS2 interacts with SOS3 and SCaBP8 with its FISL motif at C-terminus. However, luciferase activity complement assay indicates that SOS2 N-terminal is also essential for interacting with these proteins in plant.Key words: calcium signal, kinase activity, luciferase complementDue to their sessile nature, plants have developed elaborate strategies to deal with a number of environmental challenges. One overwhelming constraint is high salinity in the soil, which inhibits plant growth and decreases the agricultural productivity. Efflux and/or sequestering of sodium ion to apoplastic space/vacuolar are well-known cellular mechanisms that plants protect them from saline stress.1 Recently identified SOS (salt overly sensitive) pathway plays critical roles in maintaining ion homeostasis in response to high salinity.2 Two calcium sensors, SOS3 and SCaBP8 (SOS3-like calcium binding protein8), perceive cytosolic calcium signature triggered by salt, interact with and activate a Thr/Ser protein kinase, SOS2 and recruit it to the plasma membrane. Then, the formed SOS3-SOS2 or SCaBP8-SOS2 complex activates a PM Na+/H+ anti-porter, SOS1.2–4 Moreover, SOS2 also regulates vascular Na+/H+ antiporter activity.5 Previously, we reported that SCaBP8 and SOS3 function distinctly in activation of SOS2.3 For instance, N-terminal myristoylation of SOS3 plays an important role in salt tolerance.6 However, there is no consensus myristoylated motif in SCaBP8. Instead, an N-terminal hydrophobic domain is sufficient to facilitate the association of SCaBP8 to plasma membrane.3 In addition, SCaBP8 is phosphorylated by SOS2 under salt stress and this phosphorylation stabilizes the interaction of SOS2 and SCaBP8.4 In this report, we describe that SCaBP8 possibly is rapidly phosphorylated by SOS2 under salt stress and also phosphorylated by another stress responsible protein kinase, implying additional roles of SCaBP8 in stress responses. 相似文献
1000.
Zhen-Xia Sha Shi-Chao Xing Chang-Wei Shao Yong-Sheng Tian Xiao-Lin Liao Song-Lin Chen 《Conservation Genetics》2009,10(6):1799-1801
Ladyfish (Elops saurus Linnaeus) is an economically important marine fish species. 76 microsatellite loci were isolated from an enriched genomic library
of Elops saurus. Twelve of these markers were polymorphic in a test population with alleles per locus ranging from three to nine. The number
of observed, expected heterozygosity and polymorphism information content (PIC) per locus in 20 individuals ranged from 0.2000
to 1.0000, 0.1897–0.8846, 0.1769–0.8476, respectively. One markers significantly deviated from Hardy-Weinberg equilibrium
after Bonferroni correction analysis and there was no significant linkage disequilibrium found between pairs of markers. As
a result, 12 microsatellite markers probably should provide sufficient level of genetic diversity to investigate the fine-scale
population structure, stock management and enhancement, genetic linkage map construction and molecular marker-assisted breeding
in Elops saurus Linnaeus. 相似文献