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441.
442.
Summary Eighteen major and trace elements (Al, As, Ba, Br, Ca, Cl, Co, Cu, Fe, K, Mg, Mn, Na, Sb, Sc, Sr, V, Zn) have been determined in needles ofPicea abies by neutron activation analysis. Trees from 31 sites with different characteristics were investigated. The sampled area was 140 km2 and centered around the city of Winterthur, Switzerland.The effect of washing the needles before analysis was investigated. Washing was found to be essential for a meaningful determination of most elements. The values of the individual elements could be approximated by normal or by lognormal distributions. The width of these distributions varies greatly, being 14% for Cu and a factor of 5 for Mn. Many elements show highly significant positive or negative correlations.Whereas the levels of the major elements as determined here are in the generally accepted range, the values for most of the minor elements show very poor correspondence with published values. For some elements the present data seem to be the only available values. Distinct environmental influences were only manifest for Na, Cl, Br, and these elements show very high values at sites bordering highways.  相似文献   
443.
R2R3-MYB转录因子参与植物生长发育、激素信号传导和逆境响应等生物过程。为了揭示橡胶树MYB家族成员结构与功能,从橡胶树热研73397(RY73397)叶片中克隆HbMYB88的cDNA全长。该基因长为1 848 bp,含1 440 bp的ORF,编码479个氨基酸。HbMYB88蛋白序列包含2个SANT保守结构域,存在HTH三级结构,与拟南芥AtMYB88、AtMYB124具有高度相似性。AtMYB88、AtMYB124与干旱等逆境相关且未划分亚族。qRT-PCR分析发现HbMYB88在橡胶树茎和花中表达量高,在根、叶片、树皮和胶乳中表达量极低。热研73397组培苗叶片喷施过氧化氢(H2O2)和脱落酸(ABA)等处理后,HbMYB88表达量受诱导显著上调表达。表明HbMYB88与橡胶树抗旱等逆境反应有关,为深入研究其结构和功能打下基础。  相似文献   
444.
miR-382-3p has been reported to be upregulated in synovial membrane in knee osteoarthritis (OA). Nevertheless, its role in OA remains largely unknown. The aim of this study was to investigate the specific function and mechanisms of miR-382-3p in the course of OA. In this study, human OA chondrocytes were pretreated with interleukin-1β (IL-1β) at 5 ng/ml for 12 hr to stimulate inflammatory response and matrix metalloproteinases (MMPs) expression in chondrocytes. Meanwhile, miR-382-3p was downregulated in IL-1β-stimulated chondrocytes. In addition, we found that miR-382-3p directly interacts with connexin 43 (CX43) and attenuates the increase of cytochrome c oxidase polypeptide II, inducible nitric oxide synthase, and MMP-1/13 that is induced by IL-1β. Furthermore, our observations indicated that miR-382-3p inhibited the expression of Toll-like receptor 4 (TLR4), Myeloid differentiation primary response 88 (MyD88) and nuclear factor κB (NF-κB) in IL-1β-stimulated chondrocytes, while CX43 overexpression could partly reverse these decreases. In conclusion, miR-382-3p participated in OA may through the TLR4/MyD88/NF-κB signaling pathway by directly targeting CX43.  相似文献   
445.
Rice architecture is an important agronomic trait that affects grain yield. We characterized a tillering dwarf mutant d88 derived from Oryza sativa ssp. japonica cultivar Lansheng treated with EMS. The mutant had excessive shorter tillers and smaller panicles and seeds compared to the wild-type. A reduction in number and size of parenchyma cells around stem marrow cavity as well as a delay in the elongation of parenchyma cells caused slender tillers and dwarfism in the d88 mutant. The D88 gene was isolated via map-based cloning and identified to encode a putative esterase. The gene was expressed in most rice organs, with especially high levels in the vascular tissues. The mutant carried a nucleotide substitution in the first exon of the gene that led to the substitution of arginine for glycine, which presumably disrupted the functionally conserved N-myristoylation domain of the protein. The function of the gene was confirmed by complementation test and antisense analysis. D88, thus, represents a new category of genes that regulates cell growth and organ development and consequently plant architecture. The potential relationship between the tiller formation associated genes and D88 is discussed and future identification of the substrate for D88 may lead to the characterization of new pathways regulating plant development. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
446.
For tissue engineering applications, the preparation of biodegradable and biocompatible scaffolds is the most desirable but challenging task.  Among the various fabrication methods, electrospinning is the most attractive one due to its simplicity and versatility. Additionally, electrospun nanofibers mimic the size of natural extracellular matrix ensuring additional support for cell survival and growth. This study showed the viability of the fabrication of long fibers spanning a larger deposit area for a novel biodegradable and biocompatible polymer named poly(glycerol-dodecanoate) (PGD)1 by using a newly designed collector for electrospinning. PGD exhibits unique elastic properties with similar mechanical properties to nerve tissues, thus it is suitable for neural tissue engineering applications. The synthesis and fabrication set-up for making fibrous scaffolding materials was simple, highly reproducible, and inexpensive. In biocompatibility testing, cells derived from mouse embryonic stem cells could adhere to and grow on the electrospun PGD fibers. In summary, this protocol provided a versatile fabrication method for making PGD electrospun fibers to support the growth of mouse embryonic stem cell derived neural lineage cells.  相似文献   
447.
髓样分化因子(MyD88)是Toll受体(TLR)信号通路中的一个关键接头分子,在传递信息和介导炎症反应中具有重要的作用。对鸡MyD88(Myeloid differentiation primary response protein MyD88)的TIR(Toll-interleukin1-resistance)区域进行同源建模,并评估其可用性,为进一步研究MyD88与TLR(Toll receptor)相互作用的原理奠定基础。通过结构域分析、模板相似性搜索和序列比对、初始建模、精修和动力学优化,立体化学结构和能量合理性评估,获得未知三维结构的鸡MyD88-TIR三维模型。结果表明,鸡MyD88包含DEATH和TIR两个结构域,所模拟的MyD88-TIR三维模型二面角构象和氨基酸能量分布以及主侧链立体化学特性合理。  相似文献   
448.
The promising new anticancer agent, PI-88, is prepared by the sulfonation of the oligosaccharide phosphate fraction of the extracellular phosphomannan produced by the yeast Pichia (Hansenula) holstii NRRL Y-2448. The composition of the oligosaccharide phosphate fraction was determined by capillary electrophoresis (CE) with indirect UV detection using 6 mM potassium sorbate at pH 10.3 as the background electrolyte. Further confirmation of the composition was obtained by HPLC analysis of a sample dephosphorylated by treatment with alkaline phosphatase. The structure of the hexasaccharide component has been determined by isolation and NMR spectroscopic analysis of its dephosphorylated derivative. Additionally, the structure of a second, previously undetected tetrasaccharide component (a hexosamine) has been determined by isolation and NMR spectroscopic analysis of the acetate of its dephosphorylated derivative. It is demonstrated that CE is an ideal method for the quality control of the oligosaccharide phosphate fraction for use in the production of PI-88.  相似文献   
449.
Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-α 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-α 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.  相似文献   
450.
The zebrafish is an important model to understand the cell and molecular biology of organ and appendage regeneration. However, molecular strategies to employ reverse genetics have not yet been adequately developed to assess gene function in regeneration or tissue homeostasis during larval stages after zebrafish embryogenesis, and several tissues within the zebrafish larva are difficult to target. Intraventricular injections of gene-specific morpholinos offer an alternative method for the current inability to genomically target zebrafish genes in a temporally controlled manner at these stages. This method allows for complete dispersion and subsequent incorporation of the morpholino into various tissues throughout the body, including structures that were formerly impossible to reach such as those in the larval caudal fin, a structure often used to noninvasively research tissue regeneration. Several genes activated during larval finfold regeneration are also present in regenerating adult vertebrate tissues, so the larva is a useful model to understand regeneration in adults. This morpholino dispersion method allows for the quick and easy identification of genes required for the regeneration of larval tissues as well as other physiological phenomena regulating tissue homeostasis after embryogenesis. Therefore, this delivery method provides a currently needed strategy for temporal control to the evaluation of gene function after embryogenesis.   相似文献   
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