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81.
There are two approaches to mining text form online repositories. First, when the knowledge to be discovered is expressed directly in the documents to be mined, Information Extraction (IE) alone can serve as an effective tool for such text mining. Second, when the documents contain concrete data in unstructured form rather than abstract knowledge, Information Extraction (IE) can be used to first transform the unstructured data in the document corpus into a structured database, and then use some state-of-the-art data mining algorithms/tools to identify abstract patterns in this extracted data. This paper presents the review of several methods related to these two approaches. 相似文献
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Abnormal cell adhesion is an important contributing factor in invasion and metastasis. Here, we show that morphologically 'normal' cell-cell and cell-substratum adhesion can be restored to a poorly differentiated carcinoma cell line by activation of protein kinase C (PKC). This cell line, VACO 10MS, grows as multicellular aggregates loosely attached to the substratum. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA, 7.5 nM) induces rapid adhesive changes with 2 components. First, within 15 min of TPA the cells become closely apposed, an event resembling the 'compaction' seen in the mouse early embryo. Next, over 2 hr, the cells spread, forming a monolayer. We show that compaction depends on extracellular calcium, E-cadherin-mediated adhesion and F-actin but not on protein synthesis, microtubules or substratum adhesion. By contrast, cell spreading is independent of cadherin and extracellular Ca2+ but involves the formation of focal contacts containing alpkha(v) integrin. TPA treatment causes rapid translocation of PKC-alpha to the insoluble fraction. During compaction, actin- and PKC-alpha-containing lamellae form over the entire aggregate surface, those adjacent to the substratum appearing to initiate spreading. Compaction does not involve increased phosphorylation of the cadherin/catenin complex. We conclude that activation of PKC-alpha restores 'normal' morphology to these poorly differentiated cells. Our results are of general interest in relation to the regulation of cell adhesion and, through further investigation, may lead to identification of novel targets for therapeutic suppression of invasion and metastasis. 相似文献
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RA LaCasse KE Follis M Trahey JD Scarborough DR Littman JH Nunberg 《Canadian Metallurgical Quarterly》1999,283(5400):357-362
Current recombinant human immunodeficiency virus (HIV) gp120 protein vaccine candidates are unable to elicit antibodies capable of neutralizing infectivity of primary isolates from patients. Here, "fusion-competent" HIV vaccine immunogens were generated that capture the transient envelope-CD4-coreceptor structures that arise during HIV binding and fusion. In a transgenic mouse immunization model, these formaldehyde-fixed whole-cell vaccines elicited antibodies capable of neutralizing infectivity of 23 of 24 primary HIV isolates from diverse geographic locations and genetic clades A to E. Development of these fusion-dependent immunogens may lead to a broadly effective HIV vaccine. 相似文献
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The Federal German Water Law of 1976 postulated for the first time that a licence for the discharge of wastewater into public watercourses might only be granted when the wastewater, prior to discharge, is treated according to laid-down standards. In 1976 it was also decided that for the residual pollution load in sewage-treatment plant effluents a pollution fee has to be paid.
At present three pollution units have to be paid per capita and annually for untreated domestic wastewater. One pollution unit is assessed at 17/annum, but the price will be increased to 30/annum in future.
Since the pollution units encompass COD, nitrogen, phosphorus, heavy metals, and chlorinated hydrocarbon compounds, the pollution unit is a good tool to compare the effectiveness of treatment. For different drainage systems the residual pollution units (per litre and second) can also be calculated for low-flow conditions. 相似文献
At present three pollution units have to be paid per capita and annually for untreated domestic wastewater. One pollution unit is assessed at 17/annum, but the price will be increased to 30/annum in future.
Since the pollution units encompass COD, nitrogen, phosphorus, heavy metals, and chlorinated hydrocarbon compounds, the pollution unit is a good tool to compare the effectiveness of treatment. For different drainage systems the residual pollution units (per litre and second) can also be calculated for low-flow conditions. 相似文献
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The crying infant is a common presenting complaint and a difficult diagnostic dilemma that may represent the primary manifestation of a serious or even life-threatening condition. Although many children experience an exacerbation of the normal crying tendencies or minor ailments typical of the early months of life, a significant number of infants have underlying pathologic conditions requiring immediate intervention. This article briefly reviews current and past research on this phenomenon and presents differential diagnoses and recommendations for the evaluation and management of the acute crying episode. 相似文献