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Acoustic pulses generated by an electrical discharge (pulsed acoustics) were investigated as a means for biofouling control in two test formats, viz. a 5/8\" outside diameter titanium tube and a mockup heat exchanger. The pulsed acoustic device, when operated at 17 kV, demonstrated 95% inhibition of microfouling over a 20 ft length of titanium tube over a 4-week period, comparable to chlorination in combination with a high-velocity flush. The pulsed acoustic device inhibited microfouling over a downstream distance of 15 ft, therefore, a single pulsed acoustic device is theoretically capable of protecting at least 30 ft of tube from microfouling (15 ft on either side of the device). A correlation between acoustic intensity in the frequency range 0.01-1 MHz and the level of biofouling inhibition was observed. The threshold acoustic intensity for microfouling inhibition was determined for this frequency range. It was also observed that the orientation of the device is critical to obtaining microfouling inhibition.  相似文献   

2.
Five naphtha hydrocarbon-degrading bacteria including representative strains of the two classified species (Serratia marcescensAR1, Bacillus pumilusAR2, Bacillus carboniphilus AR3, Bacillus megaterium AR4, and Bacillus cereus AR5) were identified by 16S rDNA gene sequence in a naphtha-transporting pipeline. The naphtha-degrading strains were able to be involved in the corrosion process of API 5LX steel and also utilized the naphtha as the sole carbon source. The biodegradation of naphtha by the bacterial isolates was characterized by gas chromatography-mass spectrometry. Weight-loss measurement on the corrosion of API 5LX steel in the presence/absence of consortia grown in naphtha-water aqueous media was performed. The scanning electron microscope observation showed that the consortia were able to attack the steel API 5LX surface, creating localized corrosion (pit). The biodegradation of naphtha by the strains AR1, AR2, AR3, AR4, and AR5 showed biodegradation efficiency of about 76.21, 67.20, 68.78, 68.78, and 68.15, respectively. The role of degradation on corrosion has been discussed. This basic study will be useful for the development of new approaches for the detection, monitoring, and control of microbial corrosion in a petroleum product pipeline.  相似文献   

3.
There is a wide range of factors affecting bacterial adhesion and biofilm formation. However, in both food processing and medical settings, it is very hard to obtain suitably controlled conditions so that the factors that reduce surface colonisation and biofouling can be studied. The aim of this study was to evaluate the effect of glucose concentration, temperature and stainless steel (SS) surface roughness on biofouling by four common pathogens (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and L. monocytogenes). Among the tested variables, the untreated SS surface (3C) was shown to be fouled more than 3D polished, brushed or electropolished SS surfaces. Although an array of parameters influenced biofouling, the most promising control measure was the influence of low temperature (4?°C) that reduced biofouling even in the case of the psychrophilic Listeria monocytogenes. The study findings could significantly contribute to the prevention of SS surface contamination and consequential biofouling by food and healthcare associated pathogens.  相似文献   

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为探讨糖尿病(DM)大鼠阴茎海绵体凋亡情况,以及与API5表达的相关性,采用链脲佐菌素(STZ)诱导建立糖尿病大鼠模型,并使用APO阴茎勃起实验筛选DMED大鼠并检测各组大鼠阴茎海绵体压力(ICP).10周后取大鼠阴茎海绵体组织,通过原位末端标记法(TUNEL)和免疫组织化学法分别检测阴茎海绵体细胞凋亡及API5的表达情况.在该实验中,动物模型血糖浓度:观察组显著高于对照组(P<0.05);体重变化:观察组明显低于对照组(P<0.05);观察组ICP和ICP/MAP均明显低于对照组(P<0.05);观察组大鼠阴茎海绵体组织的细胞凋亡较对照组显著升高(P<0.05);观察组大鼠阴茎海绵体组织中API5蛋白表达较对照组明显减少.通过实验,可了解DM大鼠阴茎海绵体细胞凋亡率增加,这可能是糖尿病性勃起功能障碍的发病机制之一,而API5可能参与了DM大鼠阴茎海绵体细胞凋亡的基因调控.  相似文献   

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药用寄生植物菟丝子属,列当属和无根藤属氨基酸的分析   总被引:1,自引:0,他引:1  
本文测定了菟丝子属、列当属和无根藤属某些种的种子和植株氨基酸的种类组成和含量。结果表明,3个属种子和植株氨基酸均在15种以上,且含量丰富,特别是必需氨基酸的含量较高。文中讨论了氨基酸的药用和在种子鉴定与化学分类上的作用,探讨了开发应用的前景。  相似文献   

8.
    
5-methoxypsoralen (5-MOP) binds to human serum low density lipoproteins (LDL) according to a two-step process. Scatchard analysis of the first step yields K = 1.4 × 105 M?1 and 4 binding sites. It involves the LDL apoprotein. The second step corresponds to a solubilization, in the lipidic core, of ? 45 molecules of 5MOP per LDL molecule. It is accompanied by a large blue shift of the 5MOP fluorescence. The ability of LDL to bind 5MOP and to carry it into various cells may explain some biological effects sometimes encountered during PUVA therapy.  相似文献   

9.
簇毛麦(Dasypyrum villosum(L.)P.Candargy 2n=14,VV)是小麦改良重要的三级基因源.簇毛麦5VS染色体臂上携带抗白粉病基因Pm55、抗条锈病基因Yr5V和籽粒硬度基因Dina/Dinb等优异基因.已创制的小麦-簇毛麦T5VS.5AL和T5VS.5DL易位系为小麦抗病和品质改良提供了优...  相似文献   

10.
Summary In a first experiment, cucumber transplants (cucumis sativa L. cv. Toska) were grwon at five root-zone temperatures (RZT) ranging from 12° to 36°C. Maximum shoot growth and total leaf area were obtained at 24° and 30°C (RZT). In a second experiment, cucumber transplants were submitted to five RZT (12, 18, 24, 30 and 36°C) and five night air temperatures (NAT) that were maintained either constant at 9°, 13° and 17°C or splitted (in two halfs) at midnight (17°/12°C, 17°/9°C). Root-zone warming to 24° or 30°C increased cucumber plant growth and leaf development, but did not compensate completely the loss of productivity induced by low NAT. Split-night temperature had greater effects under the lowest NAT (17°/9°C) and at high RZT (24° or 30°C). In a third experiment, soil warming caused large increase in yields when cucumber plants were grown in the spring, but had very little effects in the fall.  相似文献   

11.
Cell division cycle 5‐like protein (Cdc5L) is a core component of the putative E3 ubiquitin ligase complex containing Prp19/Pso4, Plrg1 and Spf27. This complex has been shown to have a role in pre‐messenger RNA splicing from yeast to humans; however, more recent studies have described a function for this complex in the cellular response to DNA damage. Here, we show that Cdc5L interacts physically with the cell‐cycle checkpoint kinase ataxia‐telangiectasia and Rad3‐related (ATR). Depletion of Cdc5L by RNA‐mediated interference methods results in a defective S‐phase cell‐cycle checkpoint and cellular sensitivity in response to replication‐fork blocking agents. Furthermore, we show that Cdc5L is required for the activation of downstream effectors or mediators of ATR checkpoint function such as checkpoint kinase 1 (Chk1), cell cycle checkpoint protein Rad 17 (Rad17) and Fanconi anaemia complementation group D2 protein (FancD2). In addition, we have mapped the ATR‐binding region in Cdc5L and show that a deletion mutant that is unable to interact with ATR is defective in the rescue of the checkpoint deficiency in Cdc5L‐depleted cells. These findings show a new function for Cdc5L in the regulation of the ATR‐mediated cell‐cycle checkpoint in response to genotoxic agents.  相似文献   

12.
A rice (Oryza sativa L.) cDNA clone coding for the cytoplasmic ribosomal protein L5, which associates with 5 S rRNA for ribosome assembly, was cloned and its nucleotide sequence was determined. The primary structure of rice L5, deduced from the nucleotide sequence, contains 294 amino acids and has intriguing features some of which are also conserved in other eucaryotic homologues. These include: four clusters of basic amino acids, one of which may serve as a nucleolar localization signal; three repeated amino acid sequences; the conservation of glycine residues. This protein was identified as the nuclear-encoded cytoplasmic ribosomal protein L5 of rice by sequence similarity to other eucaryotic ribosomal 5 S RNA-binding proteins of rat, chicken, Xenopus laevis, and Saccharomyces cerevisiae. Rice L5 shares 51 to 62% amino acid sequence identity with the homologues. A group of ribosomal proteins from archaebacteria including Methanococcus vanniellii L18 and Halobacterium cutirubrum L13, which are known to be associated with 5 S rRNA, also related to rice L5 and the other eucaryotic counterparts, suggesting an evolutionary relationship in these ribosomal 5 S RNA-binding proteins.  相似文献   

13.
    
ATG16L1 plays a major role in autophagy. It acts as a molecular scaffold which mediates protein–protein interactions essential for autophagosome formation. The ATG12~ATG5–ATG16L1 complex is one of the key complexes involved in autophagosome formation. Human ATG16L1 comprises 607 amino acids with three functional domains named ATG5BD, CCD and WD40, where the C‐terminal WD40 domain represents approximately 50% of the full‐length protein. Previously, structures of the C‐terminal WD40 domain of human ATG16L1 as well as of human ATG12~ATG5 in complex with the ATG5BD of ATG16L1 have been reported. However, apart from the ATG5BD, no structural information for the N‐terminal half, including the CCD, of human ATG16L1 is available. In this study, the authors aimed to structurally characterize the N‐terminal half of ATG16L1. ATG16L111–307 in complex with ATG5 has been purified and crystallized in two crystal forms. However, both crystal structures revealed degradation of ATG16L1, resulting in crystals comprising only full‐length ATG5 and the ATG5BD of ATG16L1. The structures of ATG5–ATG5BD in two novel crystal forms are presented, further supporting the previously observed dimerization of ATG5–ATG16L1. The reported degradation points towards a high instability at the linker region between the ATG5BD and the CCD in ATG16L1. Based on this observation and further biochemical analysis of ATG16L1, a stable 236‐amino‐acid subfragment comprising residues 72–307 of the N‐terminal half of ATG16L1, covering the residual, so far structurally uncharacterized region of human ATG16L1, was identified. Here, the identification, purification, biochemical characterization and crystallization of the proteolytically stable ATG16L172–307 subfragment are reported.  相似文献   

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摘要 目的:检测CD5L水平在肝脏疾病患者血清中的变化,并分析其临床意义。方法:采用ELISA法检测41例慢性肝炎患者、192例肝硬化患者、69例肝癌患者和136例健康对照血清CD5L水平。全自动生化分析仪测定肝功能指标,Spearman相关性分析用于评估CD5L与肝功能指标的关系。受试者工作曲线(receiver operator characteristic, ROC)分析血清CD5L的潜在诊断价值。结果:与健康对照相比,CD5L水平在肝炎、肝硬化、肝癌患者中显著降低(P<0.01)。肝硬化患者血清CD5L水平较肝炎及肝癌患者显著降低(P<0.01)。肝硬化代偿期和失代偿期患者血清CD5L水平无显著差异。血清CD5L水平与FIB-4指数(肝纤维化评分)呈显著负相关(r=-0.2688,P=0.0001)。Spearman相关性分析结果显示:在肝炎患者中,血清CD5L与总胆红素(T-BIL)、直接胆红素(D-BIL)、间接胆红素(I-BIL)显著正相关;在肝硬化患者中,CD5L与其他肝功指标无显著相关性;在肝癌患者中,CD5L与碱性磷酸酶(ALP)显著正相关。以健康人为对照组,肝硬化患者为病例组,ROC分析显示血清CD5L的诊断特异性为85.3%,敏感性为77.1%。结论:CD5L水平在肝炎、肝硬化及肝癌患者血清中显著降低,且在肝硬化患者中最低。CD5L水平与肝纤维化评分FIB-4指数负相关,可作为监测肝纤维化进展的潜在生物标志物。  相似文献   

16.
Ribosomal protein L5 is a shuttling protein that, in Xenopus oocytes, is involved in the nucleocytoplasmic transport of 5S rRNA. As demonstrated earlier, L5 contains three independent nuclear import signals (NLSs), which function in oocytes as well as in somatic cells. Upon physical separation, these NLSs differ in respect to their capacity to bind to nuclear import factors in vitro and to mediate the nuclear import of a heterologous RNP in vivo. As reported in this communication, analysis of the in vitro nuclear import activity of these three NLSs reveals that they also differ in respect to their requirements for cytosolic import factors and Ran. Nuclear import mediated by the N-terminal and the central NLS depends on cytosolic import factor(s) and Ran, whereas import via the C-terminal NLS occurs independently from these factors. Thus, the presence of multiple NLSs in ribosomal protein L5 appears to allow for efficient nuclear transport via utilisation of multiple, mechanistically different import pathways.  相似文献   

17.
对嗜酸乳杆菌S层蛋白的提取方法进行了改进.用酸性5mol/L LiCl法,中性5mol/L LiCl法和8mol/L尿素法提取嗜酸乳杆菌的表层蛋白,考马斯亮兰法测蛋白浓度,进行常规SDS-PAGE,用Gel—Pro软件进行数据分析,得出其中酸性5mol/L LiCl法提取表层蛋白百分含量最多.分析影响提取条件的因素,设置0、4、室温(25℃)3个温度梯度和10、15、20、25、30min 5个时间梯度,进行常规SDS-PAGE,检测提取表层蛋白的效果.Sephadex G-100柱分离中性5mol/L LiCl法和8mol/L尿素法提取嗜酸乳杆菌的表层蛋白获得SA蛋白.酸性5mol/L LiCl法可用于分析各种表层蛋白;中性5mol/L LiCl法和8mol/L尿素法用于提取43kDa的SA蛋白.25℃处理15min得到最大量的表层蛋白.  相似文献   

18.
From a readily available 5-C-Me ribofuranoside, we have realized a reliable route to valuable 5′-deoxy-5′-amino-5′-C-methyl adenosine derivatives at gram scale with confirmed stereochemistry. These adenosine derivatives are useful starting materials for the preparation of 5′-deoxy-5′-amino-5′-C-methyl adenosine derivatives with higher complexity. From one of the new adenosine derivatives, some 5′-deoxy-5′-amino-5′-C-methyl adenosine DOT1L inhibitors were prepared in several steps. Data from DOT1L assay indicated that additional 5′-C-Me group improved the enzyme inhibitory activity.  相似文献   

19.
  总被引:1,自引:0,他引:1  
The effects of ribosomal protein L5 on the conformation of 5 S rRNA in the 5 S rRNA-protein L5 complex extracted from rat liver ribosomes have been studied by laser Raman spectroscopy. A comparison of the spectra shows small protein-induced conformational changes in the 5 S rRNA, but most of the base-paired regions appear to be present in the complex with protein L5 as well as in the free 5 S rRNA. Furthermore specific interactions between 5 S rRNA and protein L5 are indicated. Cytosine (and/or uracil) residues in single-stranded regions and the N(7) of guanine are engaged in interactions with the protein as suggested by the Raman data.  相似文献   

20.
The monoclonal L5 antibody reacts with an N-glycosidically linked carbohydrate structure which is present on the neural cell adhesion molecule L1, neural chondroitin sulfate proteoglycans, and other not yet identified glycosylated proteins. Using this antibody, we isolated and characterized proteoglycans from adult mouse brain and cultured astrocytes biosynthetically labeled with Na2 35SO4 and a 3H-amino acid mixture. Our data suggest that the L5 proteoglycans of both sources are identical in their biochemical properties. The apparent molecular mass of the L5 proteoglycan is approximately 500 kDa. Digestion of the iodinated L5 proteoglycan from mouse brain and of the [35S]methionine-labeled L5 proteoglycan from cultured astrocytes with proteinase-free chondroitinases ABC and AC revealed three major core proteins with apparent molecular masses of approximately 380, 360, and 260 kDa. These represent molecularly distinct protein cores.  相似文献   

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