610 resultados para OKAMURAI YAMADA
Resumo:
Two new brominated diterpenes, namely, laurendecumtriol (1) and 11-O-deacetylpinnaterpene C (2), one new polybromoindole, 2,3,4,6-tetrabromo-1-methyl-1H-indole (7), and six known natural products were isolated and identified from the marine red alga Laurencia decumbens. Their structures were elucidated on the basis of detailed spectroscopic and mass-spectrometric analysis as well as by comparison with literature data. Based on 2D-NMR experiments, the previously reported NMR data for pinnaterpene C (3) were reassigned.
Resumo:
凹顶藻属(Laurencia)海藻在分类学上属于红藻门(Rhodophyta)、红藻纲(Rhodophyceae)、仙菜目(Ceramiales)、松节藻科(Rhodomalaceae),主要分布于热带、亚热带和温带海域的低潮线附近及深海部分,约135种,中国有20种以上。凹顶藻次级代谢产物的结构类型主要包括倍半萜、二萜、三萜/聚醚和C15-多聚乙酰等,冈村凹顶藻中,倍半萜和C15-多聚乙酰最为常见,且以卤代著称。本文对凹顶藻卤代机制的研究进行了总结,并对最近10年来从凹顶藻中分离到的倍半萜、C15-多聚乙酰类成分及其合成研究进行了综述,同时对采自山东和广东的两种冈村凹顶藻(Laurencia okamurai Yamada)的化学成分进行了比较研究,发现生长在不同地理位置的同种凹顶藻化学成分有很大差异。 干燥并粉碎的冈村凹顶藻(L. okamurai)分别进行有机溶剂提取,粗提物通过硅胶柱层析、凝胶Sephadex LH-20柱层析、反相硅胶柱层析、制备薄层层析等方法分离纯化得单体化合物,利用超导核磁共振、质谱和红外光谱等现代波谱技术鉴定化合物的结构。从上述采自不同地点的冈村凹顶藻中分离鉴定的化合物共计30个,包括新化合物8个,依次是laurenokamurenes A-E (LA1-LA5),laurenokamurin (LA6),laurenokaldehyde (LA7)和isochlorolaurenol (LB1),新天然产物1个 (LA12)和已知化合物21个。其中,采自山东的冈村凹顶藻次级代谢产物结构类型相对复杂多样,从中分离到的化合物包括bisabolane型倍半萜4个,chamigrane型倍半萜5个,laurane型倍半萜6个,C15-多聚乙酰类化合物5个,其他类型化合物1个(见第III页);从采自广东的冈村凹顶藻中分离鉴定的化合物主要为7个laurane型倍半萜和2个其他类型的化合物(见第IV页)。 对分离鉴定的部分单体化合物进行了抗细菌(金黄色葡萄球菌)活性筛选,结果表明所有的测试样品都不具有抗金黄色葡萄球菌活性。
Resumo:
Seven new sesquiterpenes (1-7), together with seven known sesquiterpenes, aplysin (8), aplysinol (9), gossonorol (10), 7,10-epoxy-ar-bisabol-11-ol (11), 10-epi-7,10-epoxy-ar-bisabol-11-ol (12), johnstonol (13), and laurebiphenyl (14), have been isolated from the red alga Laurencia tristicha. The structures of new compounds were established as laur-11-en-2,10-diol (1), laur-11-en-10-ol (2), laur-11-en-1,10-diol (3), 4-bromo-1,10-epoxylaur-11-ene (4), cyclolauren-2-ol (5), laurentristich-4-ol (6), and ar-bisabol-9-en-7,11-diol (7) by means of spectroscopic methods including IR, HRMS, and ID and 21) NMR techniques. Compound 6 possessed a novel rearranged skeleton. All compounds were tested against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), hepatoma (Bel 7402), colon cancer (HCT-8), and HELA cell lines. Laurebiphenyl (14) showed moderate cytotoxicity against all tested cell lines, with IC50 values of 1.68, 1.22, 1.91, 1.77, and 1.61 mu g/mL, respectively. Other compounds were inactive (IC50 > 10 mu g/mL).
Resumo:
A new rearranged chamigrane sesquiterpene, named laurenokamurin, was isolated from the marine red alga Laurencia okamurai. Its structure was determined on the basis of spectroscopic methods. (C) 2008 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Resumo:
A one-dimensional water column model using the Mellor and Yamada level 2.5 parameterization of vertical turbulent fluxes is presented. The model equations are discretized with a mixed finite element scheme. Details of the finite element discrete equations are given and adaptive mesh refinement strategies are presented. The refinement criterion is an "a posteriori" error estimator based on stratification, shear and distance to surface. The model performances are assessed by studying the stress driven penetration of a turbulent layer into a stratified fluid. This example illustrates the ability of the presented model to follow some internal structures of the flow and paves the way for truly generalized vertical coordinates. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
Ishige okamurai Yendo, determined by M.J.Wynne 2006
Resumo:
Disasters, particularly those triggered by nature are often followed by a swift humanitarian relief response to address the resultant emergencies. These efforts are then transitioned through the medium recovery stage, eventually aimed at providing a long term post-disaster reconstruction solution. Emergency humanitarian relief focuses on responding to the immediate need for restoration of basic services, medical treatment and medical supplies, food and temporary shelter, and is a short term strenuous effort. Reconstruction of permanent houses, on the other hand, is a continuous process that often requires decades of effort to return a community to normality. Whilst emergency relief is generally perceived to be very effective, post-disaster housing reconstruction projects often fail to meet their set objectives. This paper outlines and discusses factors that contribute to the failure of post-disaster housing reconstruction projects and the subsequent immediate and long term negative impacts of failure on project outcomes.
Resumo:
Long undersea debris runout can be facilitated by a boundary layer formed by weak marine sediments under a moving slide mass. Undrained loading of such offshore sediment results in a profound drop of basal shear resistance, compared to subaerial shear resistance, enabling long undersea runout. Thus large long-runout submarine landslides are not truly enigmatic (Voight and Elsworth 1992, 1997), but are understandable in terms of conventional geotechnical principles. A corollary is that remoulded undrained strength, and not friction angle, should be used for basal resistance in numerical simulations. This hypothesis is testable via drilling and examining the structure at the soles of undersea debris avalanches for indications of incorporation of sheared marine sediments, by tests of soil properties, and by simulations. Such considerations of emplacement process are an aim of ongoing research in the Lesser Antilles (Caribbean Sea), where multiple offshore debris avalanche and dome-collapse debris deposits have been identified since 1999 on swath bathymetric surveys collected in five oceanographic cruises. This paper reviews the prehistoric and historic collapses that have occurred offshore of Antilles arc islands and summarizes ongoing research on emplacement processes.
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The year 2010 was the wettest year on record for Queensland, Australia and the wettest year since 1974 for Southeast Queensland. The extremely heavy rain in early January 2011 fell on the catchments of heavily saturated Brisbane and Stanley Rivers systems resulting in significant runoff which rapidly produced a widespread and devastating flood event. The area of inundation was equivalent to the total land area of France and Germany combined. Over 200,000 people were affected leaving 35 people dead and 9 missing. The damage bill was estimated at over $1B and cost to the economy at over $10B with over 30,000 homes and 6,000 business flooded and 86 towns and regional centres affected. The need to disburse disaster funding in a prompt manner to the affected population was paramount to facilitate individuals getting their lives back to some normality. However, the payout of insurance claims has proved to be a major area of community anger. The ongoing impasse in payment of insurance compensation is attributed to the nature and number of claims, confusing definition of flooding and the lack or accuracy of information needed to determine individually the properties affected and legitimacy of claims. Information was not readily available at the micro-level including, extent and type of inundation, flood heights at property level and cause of damage. Events during the aftermath highlighted widespread community misconceptions concerning the technical factors associated with the flood event and the impact of such on access to legitimate compensation and assistance. Individual and community wide concerns and frustration, anger and depression, have arisen resulting from delays in the timely settlement of insurance claims. Lessons learnt during the aftermath are presented in the context of their importance as a basis for inculcating communities impacted by the flood event with resilience for the future.
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This paper presents an approach to modelling the resilience of a generic (potable) water supply system. The system is contextualized as a meta-system consisting of three subsystems to represent the natural catchment, the water treatment plant and the water distribution infrastructure for urban use. An abstract mathematical model of the meta-system is disaggregated progressively to form a cascade of equations forming a relational matrix of models. This allows the investigation of commonly implicit relationships between various operational components within the meta system, the in-depth understanding of specific system components and influential factors and the incorporation of explicit disturbances to explore system behaviour. Consequently, this will facilitate long-term decision making to achieve sustainable solutions for issues such as, meeting a growing demand or managing supply-side influences in the meta-system under diverse water availability regimes. This approach is based on the hypothesis that the means to achieve resilient supply of water may be better managed by modelling the effects of changes at specific levels that have a direct or in some cases indirect impact on higher-order outcomes. Additionally, the proposed strategy allows the definition of approaches to combine disparate data sets to synthesise previously missing or incomplete higher-order information, a scientifically robust means to define and carry out meta-analyses using knowledge from diverse yet relatable disciplines relevant to different levels of the system and for enhancing the understanding of dependencies and inter-dependencies of variable factors at various levels across the meta-system. The proposed concept introduces an approach for modelling a complex infrastructure system as a meta system which consists of a combination of bio-ecological, technical and socio-technical subsystems.
Resumo:
Since the identification of the gene family of kallikrein related peptidases (KLKs), their function has been robustly studied at the biochemical level. In vitro biochemical studies have shown that KLK proteases are involved in a number of extracellular processes that initiate intracellular signaling pathways by hydrolysis, as reviewed in Chapters 8, 9, and 15, Volume 1. These events have been associated with more invasive phenotypes of ovarian, prostate, and other cancers. Concomitantly, aberrant expression of KLKs has been associated with poor prognosis of patients with ovarian and prostate cancer (Borgoño and Diamandis, 2004; Clements et al., 2004; Yousef and Diamandis, 2009), with prostate-specific antigen (PSA, KLK3) being a long standing, clinically employed biomarker for prostate cancer (Lilja et al., 2008). Data generated from patient samples in clinical studies, alongwith biochemical activity, suggests that KLKs function in the development and progression of these diseases. To bridge the gap between their function at the molecular level and the clinical need for efficacious treatment and prognostic biomarkers, functional assessment at the in vitro cellular level, using various culture models, is increasing, particularly in a three-dimensional (3D) context (Abbott, 2003; Bissell and Radisky, 2001; Pampaloni et al., 2007; Yamada and Cukierman, 2007).
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The level of 67 kDa laminin receptor (67LR) expression on breast and colon tumor cell surfaces was previously shown to be correlated with the capacity of tumor cells to metastasize. In the present work we investigate the effects of progestins and estrogen on the expression of 67LR in two sublines of the T47D human breast cancer cells: weakly tumorigenic, poorly invasive parental T47D cells and a highly tumorigenic, more invasive T47Dco subclone. Inmmunoblotting with an affinity purified antibody directed against a synthetic peptide recognizes the 67LR in these cells. 67LR expression in the T47Dco subclone is 5,5-fold higher than in their parental T47D cells. Treatment of T47D cells with 1 nM of the synthetic progestin R5020 results in a 4-fold increase in 67LR protein expression. Estrogen also induced 67LR expression, but only by 1.5-fold. The progestin-stimulated expression of the 67LR correlates with a 4.3-fold increase in attachment of T47D cells to laminin. A monoclonal antibody, mAb 13, directed against β1 integrin, completely blocks the attachment of T47D cells to fibronectin, only partially inhibits the attachment of T47D cells to laminin, and appears not to affect the progestin-stimulated laminin attachment of T47D cells. A new antiprogestin, ZK 112.993, significantly inhibits both progestin-stimulated 67LR expression and the increased attachment to laminin. These results suggest a possible role for progestin in mediating one of the multiple events thought to be important in metastasis of steroid receptor positive human breast cancer cells.