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五峰垃圾填埋场渗滤液污染特征及处理系统 总被引:1,自引:0,他引:1
系统分析了五峰垃圾填埋场渗滤液中COD,BOD_5的季节变化特征,并对该填埋场的污水处理系统进行了研究和评价。 相似文献
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The 35S promoter of the cauliflower mosaic virus (CaMV) contains a tandem repeat of the sequence TGACG in the region -83 to -63. This 21-base pair (bp) sequence, called as-1, is involved in root expression of the 35S promoter. When inserted in a promoter of a gene expressed specifically in photosynthetic tissues, as-1 confers high level expression in roots. We have described a factor, ASF-1, that binds specifically to as-1 in vitro. There is a good correlation between ASF-1 binding affinity to as-1 related sequences in vitro and the function of these sequences in vivo. These results strongly suggest that ASF-1 is responsible for the function of as-1. Here we report the isolation of tobacco complementary DNA clones encoding two TGACG-sequence-specific binding-proteins (TGA1a and TGA1b). Sequence analysis of the cDNA clones shows that both proteins contain a basic region that shows high homology to a stretch of basic amino acids in the nuclear factors CREB, GCN4, and c-Jun to a 'leucine-zipper' region. On the basis of binding specificity we propose TGA1a to be a good candidate for ASF-1. 相似文献
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Auroral substorm response to solar wind pressure shock 总被引:1,自引:0,他引:1
Two cases of auroral substorms have been studied with the Polar UVI data, which were associated with solar wind pressure shock
arriving at the Earth. The global aurora activities started about 1–2 min after pressure shocks arrived at dayside magnetopause,
then nightside auroras intensified rapidly 3–4 min later, with auroral substorm onset. The observations in synchronous orbit
indicated that the compressing effects on magnetosphere were observed in their corresponding sites about 2 min after the pressure
shocks impulse magnetopause. We propose that the auroral intensification and substorm onset possibly result from hydromagnetic
wave produced by the pressure shock. The fast-mode wave propagates across the magnetotail lobes with higher local Alfven velocity,
magnetotail was compressed rapidly and strong lobe field and cross-tail current were built in about 1–2 min, and furthermore
the substorm was triggered due to an instability in current sheet. 相似文献
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Crystal structure of TFIID TATA-box binding protein. 总被引:48,自引:0,他引:48
D B Nikolov S H Hu J Lin A Gasch A Hoffmann M Horikoshi N H Chua R G Roeder S K Burley 《Nature》1992,360(6399):40-46
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Chiow KH Tan Y Chua RY Huang D Ng ML Torta F Wenk MR Wong SH 《Cellular and molecular life sciences : CMLS》2012,69(9):1505-1521
Since being introduced globally as aspirin in 1899, acetylsalicylic acid has been widely used as an analgesic, anti-inflammation,
anti-pyretic, and anti-thrombotic drug for years. Aspirin had been reported to down-regulate surface expression of CD40, CD80,
CD86, and MHCII in myeloid dendritic cells (DC), which played essential roles in regulating the immune system. We hypothesized
that the down-regulation of these surface membrane proteins is partly due to the ability of aspirin in regulating trafficking/sorting
of endocytosed surface membrane proteins. By using an established epidermoid carcinoma cell line (A-431), which overexpresses
the epidermal growth factor receptor (EGFR) and transferrin receptor (TfnR), we show that aspirin (1) reduces cell surface
expression of EGFR and (2) accumulates endocytosed-EGFR and -TfnR in the early/sorting endosome (ESE). Further elucidation
of the mechanism suggests that aspirin enhances recruitment of SNX3 and SNX5 to membranes and consistently, both SNX3 and
SNX5 play essential roles in the aspirin-mediated accumulation of endocytosed-TfnR at the ESE. This study sheds light on how
aspirin may down-regulate surface expression of EGFR by inhibiting/delaying the exit of endocytosed-EGFR from the ESE and
recycling of endocytosed-EGFR back to the cell surface. 相似文献
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Macroautophagy, the process by which cytosolic components and organelles are engulfed and degraded by a double-membrane structure,
could be viewed as a specialized, multistep membrane transport process. As such, it intersects with the exocytic and endocytic
membrane trafficking pathways. A number of Rab GTPases which regulate secretory and endocytic membrane traffic have been shown
to play either critical or accessory roles in autophagy. The biogenesis of the pre-autophagosomal isolation membrane (or phagophore)
is dependent on the functionality of Rab1. A non-canonical, Atg5/Atg7-independent mode of autophagosome generation from the
trans-Golgi or endosome requires Rab9. Other Rabs, such as Rab5, Rab24, Rab33, and Rab7 have all been shown to be required,
or involved at various stages of autophagosomal genesis and maturation. Another small GTPase, RalB, was very recently demonstrated
to induce isolation membrane formation and maturation via its engagement of the exocyst complex, a known Rab effector. We
summarize here what is now known about the involvement of Rabs in autophagy, and discuss plausible mechanisms with future
perspectives. 相似文献