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121.
Mechanical stimulation (MS), widely existing but usually ignored in nature, is one of the major environmental stress factors. MS by increasing the rotational speed of shaker incubator could alleviate a decrease in vitality of tobacco (Nicotiana tabacum L.) suspension cultured cells and reduce the accumulation of MDA under chilling stress at 1°C, which in turn improved survival percentage under chilling stress and regrowth ability of tobacco suspension cells after chilling stress. In addition, MS could increase the activity of Δ1-pyrroline-5-carboxylate synthetase (P5CS) and induce the accumulation of endogenous proline in tobacco cells; exogenously applied proline also could enhance its endogenous level under normal culture conditions and survival percent-age of the cells under chilling stress. These results suggest that MS could improve chilling tolerance of tobacco suspension cells and the acquisition of this chilling tolerance was related to proline. 相似文献
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Gong Zhang Witold Kinsner Bin Huang 《Computer methods in biomechanics and biomedical engineering》2013,16(6):701-707
This paper presents an electrocardiogram (ECG) data mining scheme based on the ECG frame classification realised by a dynamic time warping (DTW) matching technique, which has been used successfully in speech recognition. We use the DTW to classify ECG frames because ECG and speech signals have similar non-stationary characteristics. The DTW mapping function is obtained by searching the frame from its end to start. A threshold is setup for DTW matching residual either to classify an ECG frame or to add a new class. Classification and establishment of a template set are carried out simultaneously. A frame is classified into a category with a minimal residual and satisfying a threshold requirement. A classification residual of 1.33% is achieved by the DTW for a 10-min ECG recording. 相似文献
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Min Wang Heng Jiang Zhiguo Song Hong Gong 《Preparative biochemistry & biotechnology》2013,43(4):372-379
Abstract An efficient synthesis of 3,4-dihydropyrimidin-2(1H)-ones from aldehydes, 1,3-dicarbonyl compounds, and urea using copper nitrate under refluxing temperature in ethanol was described. Compared with other Lewis copper salts, copper nitrate proved to be the most efficient. The advantages of the new method were good yields (61–93%), short reaction time (0.4–3 h), and inexpensive catalyst. 相似文献
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Leixiang Yang Jingxu Gong Feng Wang Yongmin Zhang Yanguang Wang Xiaojiang Hao 《Journal of enzyme inhibition and medicinal chemistry》2013,28(4):399-404
In this work, we evaluated the antioxidant properties of the eight novel silybin analogues for their capacity to scavenge free radicals including superoxide anion radicals and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in vitro. Compound 7d demonstrated an excellent antioxidant effect in scavenging superoxide anion free radical with an IC50 value of 26.5 μM, while the IC50 of quercetin (the reference compound) was 38.1 μM. Compounds 7b, 7e, 7h showed certain scavenging activities for both types of free radicals. 相似文献
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Gene-derived simple sequence repeats (genic SSRs), also known as functional markers, are often preferred over random genomic markers because they represent variation in gene coding and/or regulatory regions. We characterized 544 genic SSR loci derived from 138 candidate genes involved in wood formation, distributed throughout the genome of Populus tomentosa, a key ecological and cultivated wood production species. Of these SSRs, three-quarters were located in the promoter or intron regions, and dinucleotide (59.7%) and trinucleotide repeat motifs (26.5%) predominated. By screening 15 wild P. tomentosa ecotypes, we identified 188 polymorphic genic SSRs with 861 alleles, 2–7 alleles for each marker. Transferability analysis of 30 random genic SSRs, testing whether these SSRs work in 26 genotypes of five genus Populus sections (outgroup, Salix matsudana), showed that 72% of the SSRs could be amplified in Turanga and 100% could be amplified in Leuce. Based on genotyping of these 26 genotypes, a neighbour-joining analysis showed the expected six phylogenetic groupings. In silico analysis of SSR variation in 220 sequences that are homologous between P. tomentosa and Populus trichocarpa suggested that genic SSR variations between relatives were predominantly affected by repeat motif variations or flanking sequence mutations. Inheritance tests and single-marker associations demonstrated the power of genic SSRs in family-based linkage mapping and candidate gene-based association studies, as well as marker-assisted selection and comparative genomic studies of P. tomentosa and related species. 相似文献
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Sheng Hua Mu Yao Soma Vignarajan Paul Witting Leila Hejazi Zhen Gong Ying Teng Marzieh Niknami Stephen Assinder Des Richardson Qihan Dong 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2013,1831(6):1146-1157
Constitutive phosphorylation of protein kinase B (AKT) is a common feature of cancer caused by genetic alteration in the phosphatase and tensin homolog (PTEN) gene and is associated with poor prognosis. This study determined the role of cytosolic phospholipase A2α (cPLA2α) in AKT, extracellular signal-regulated kinase (ERK) and androgen receptor (AR) signaling in PTEN-null/mutated prostate cancer cells. Doxycycline (Dox)-induced expression of cPLA2α led to an increase in pAKT, pGSK3β and cyclin D1 levels in LNCaP cells that possess a PTEN frame-shift mutation. In contrast, silencing cPLA2α expression with siRNA decreased pAKT, pGSK3β and cyclin D1 levels in both PC-3 (PTEN deletion) and LNCaP cells. Silencing of cPLA2α decreased pERK and AR protein levels. The inhibitory effect of cPLA2α siRNA on pAKT and AR protein levels was reduced by the addition of arachidonic acid (AA), whereas the stimulatory effect of AA on pAKT, pERK and AR levels was decreased by an inhibitor of 5-hydroxyeicosatetraenoic acid production. Pharmacological blockade of cPLA2α with Efipladib reduced pAKT and AR levels with a concomitant inhibition of PC-3 and LNCaP cell proliferation. These results demonstrate an important role for cPLA2α in sustaining AKT, ERK and AR signaling in PTEN-null/mutated prostate cancer cells and provide a potential molecular target for treating prostate cancer. 相似文献