A new brominated phenylpropylaldehyde and its dimethyl acetal from red alga Rhodomela confervoides

A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde, 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl) propylaldehyde dimethyl acetal and 3-bromo-4,5-dihydroxybenzoic acid methyl ester by spectroscopic techniques including IR, HRFABMS, ID and 2DNMR experiments.

Two new bromophenols from red alga Rhodomela confervoides

Two new bromophenols were isolated from Rhodomela confervoides. Their structures were elucidated as 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-hydroxymethyldiphenylmethane and 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane by spectroscopic methods including IR, HREIMS, 1D and 2D NMR techniques.

Antibacterial bromophenols from the marine red alga Rhodomela confervoides

Two bromophenols, together with three known compounds, were isolated from the methanolic extract of the marine alga, Rhodomela confervoides. By means of MS and NMR spectroscopic analyses, they were identified as 3-bromo-4-[2,3-dibromo-4,5-dihydroxyphenyl] methyl-5-(hydroxymethyl) 1,2-benzenediol (1) and 3-bromo-4-[2,3-dibromo-4,5-dihydroxyphenyl] methyl-5- (ethoxymethyl) 1,2-benzenediol (2). Three known compounds were also isolated, namely 3-bromo-4-[2,3-dibromo-4,5-dihydroxyphenyl] methyl-5-(methoxymethyl) 1,2-benzenediol (3), 4,4'- methylenebis [5,6-dibromo-1,2-benzenediol] (4) and bis (2,3-dibromo-4,5-dihydroxybenzyl) ether (5). Compound 5 was the most active against five strains of bacteria with the MIC less than 70 mug/ml, while compounds 2, 3 and 4 exhibited moderate activity.

Sorption and desorption of lead (II) from wastewater by green algae Cladophora fascicularis

Biosorption is an effective method to remove heavy metals from wastewater. In this work, adsorption features of Cladophora fascicularis were investigated as a function of time, initial pH, initial Pb(II) concentrations, temperature and co-existing ions. Kinetics and equilibria were obtained from batch experiments. The biosorption kinetics followed the pseudo-second order model. Adsorption equilibria were well described by the Langmuir and Freundlich isotherm models. The maximum adsorption capacity was 198.5 mg/g at 298 K and pH 5.0. The adsorption processes were endothermic and the biosorption heat was 29.6 kJ/mol. Desorption experiments indicated that 0.01 mol/L Na(2)EDTA was an efficient desorbent for the recovery of Pb(II) from biomass. IR spectrum analysis suggested amido or hydroxy, C=O and C-O could combine intensively with Pb(II). (C) 2006 Elsevier B.V. All rights reserved.

Effect of ethanol extract of alga Laurencia supplementation on DNA oxidation and alkylation damage in mice

Laurencia terpenoid extract (LET) had been extracted from the red alga Laurencia tristicha. The study is to investigate the effects of LET supplementation on DNA oxidation and alkylation damages in mice. Forty healthy kunming mice weighing between 18g and 25g were randomly assigned into 4 groups, each consisting of ten animals. The mice were orally intubated respectively for 60 days with the designed concentrations of LET (25, 50, 100 mg/kg b.w.) for three exposed groups and salad oil (0.2 ml) for the blank group. Food and water were free for the animals. Mice in the blank and exposed groups were sacrificed after the last treatment and the blood of each animal was quickly taken for further experiments. The spontaneous and oxidized DNA damages of peripheral lymphocytes induced by H2O2 were analysed by SCGE. O-6-Methy-guanine (O-6-MeG) was measured by high performance capillary zone electrophoresis. There was no significantly difference in DNA spontaneous damage on peripheral lymphocytes of all the mice. The oxidative DNA damage in the 50 mg/Kg body weight supplement group are 286AU with the oxidation of 10 mu mol/L H2O2, significantly lower than the blank group 332AU (p<0.05). The contents of O-6-MeG in plasma in the 50mg/kg b.w. and 100mg/kg b.w. supplement group were 1.50 mu mol/L andl.88 mu mol/L, significantly lower than that of the blank group, which was 2.89 mu mol/L(p<0.05). The results from the present study indicated that the LET were rich in terpenoids and safety to be taken orally and it could improve antioxidative and decrease DNA damage effectively.

The chemical constituents from red alga Gymnogongrus flabelliformis Harv.

Eight compounds were isolated from red alga Gymnogongrus flabelliformis Harv. In normal phase silica gel, Sephadex LH-20 gel column chromatography, reverse phase HPLC, and recrystallization. Based on MS and 1D NMR spectroscopic data, their structures were determined as: stigmast-4-en-3-one (I), cholest-4-en-3-one (II), cholesterol (III), uracil (IV), uridine (V), adenosine (VI), succinic acid (VII), and 5-hydroxy-4-methyl-5-pentyl-2,5-dihydro-furan-2-on (VIII). All of them were obtained from this species for the first time. Cytotoxicity of these compounds was screened using standard MTT method, but all the compounds were inactive (IC50 > 10 mu g/ml).

Inbreeding depression for various traits in two cultured populations of the American bay scallop, Argopecten irradians irradians Lamarck (1819) introduced into China

This paper examines the effect of inbreeding level of population on the magnitude of inbreeding depression expressed by comparing them between two cultured populations (A and B) in the hermaphroditic animal of the bay scallop Argopecten irradians irradians. Population A is expected to have less genetic variations and higher inbreeding level due to longer cultured history (20 generations) and less "ancestral" individuals (26 individuals) than population B due to shorter cultured history (4 generations) and more "ancestral" individuals (406 individuals). Two groups within each population were produced, one using self-fertilization and one using mass-mating within the same population. Selfed offspring (AS and BS) from two populations both had lower fitness components than their mass-mated counterparts (AM and BM) and exhibited inbreeding depression for all examined traits, e.g. lower hatching, less viability and slower growth, indicating that inbreeding depression is a common feature in this animal. Fitness components in all traits of offspring from population A significantly differed those from population B and the magnitude of inbreeding depression for all traits in population A with higher inbreeding level was significantly smaller than that in population B with lower inbreeding level, indicating that both fitness components and magnitude of inbreeding depression were significantly affected by inbreeding level of populations and genetic load harbored in population A may be partially purged through inbreeding. Moreover, the magnitude of inbreeding depression in the two populations both varied among traits and life history stages. The present results support the partial-dominance hypothesis of inbreeding depression. (C) 2008 Elsevier B.V. All rights reserved.

Biosorption of copper (II) and lead (II) from aqueous solutions by nonliving green algae Cladophora fascicularis: Equilibrium, kinetics and environmental effects

Biosorption of Cu2+ and Pb2+ by Cladophora fascicularis was investigated as a function of initial pH, initial heavy metal concentrations, temperature and other co-existing ions. Adsorption equilibriums were well described by Langmuir and Freundlich isotherm models. The maximum adsorption capacities were 1.61 mmol/ g for Cu2+ and 0.96 mmol/ g for Pb2+ at 298K and pH 5.0. The adsorption processes were endothermic and biosorption heats calculated by the Langmuir constant b were 39.0 and 29.6 kJ/ mol for Cu2+ and Pb2+, respectively. The biosorption kinetics followed the pseudo- second order model. No significant effect on the uptake of Cu2+ and Pb2+ by co-existing cations and anions was observed, except EDTA. Desorption experiments indicated that Na(2)EDTA was an efficient desorbent for the recovery of Cu2+ and Pb2+ from biomass. The results showed that Cladophora fascicularis was an effective and economical biosorbent material for the removal and recovery of heavy metal ions from wastewater.

Extraction of the polysaccharides from five algae and their potential antioxidant activity in vitro

The sulfated polysaccharides extracted from algae possess excellent antioxidant activities. In this study, we prepared five polysaccharides extracted from five algae including one brown alga Laminaria japonica. one red alga Porphyra haitanensis and three green algae Ulva pertusa, Enteromorpha linza and Bryopsis plumose. And then the antioxidant activities of all the samples were investigated including scavenging effects of superoxide and hydroxyl radicals, and reducing power. The chemical analysis and FT-IR spectrum showed these extracts were polysaccharides. And in addition, we found that certain polysaccharide exhibited stronger antioxidant activity in certain antioxidant activity. Factors effecting and attributing to radical scavenging effect need to be further studied. (C) 2010 Elsevier Ltd. All rights reserved.

Two new norisoprenoid derivatives from the red alga Gymnogongrus flabelliformis

Two new norisoprenoid derivatives have been isolated from the red alga Gymnogongrus flabelliformis. Their structures were elucidated as (3R, 6R, 7E)-(+)-3-O-phenylacetyl-4,7-megastigmadiene-9-one and (3R,7E)-(-)-3-O-phenylacetyl-5,7-megastigmadiene-9-one, respectively, by spectroscopic methods including HRMS, 1D and 2D NMR techniques.

Sustained response to selection in an introduced population of the hermaphroditic bay scallop Argopecten irradians irradians Lamarck (1819)

Introduced species often start with limited genetic variability, which is problematic for selective breeding. The problem of inbreeding can be exasperated by hermaphroditism. The bay scallop Argopecten irradians irradians is a hermaphroditic species that has been introduced to and now supports a major aquaculture industry in China. Positive response to selection for fast growth was observed in one of the less inbred stocks in a previous study. In this study, we evaluated selection for the second generation to determine if response to selection can be sustained in this introduced population of a hermaphroditic species. Response to selection, realized heritability for the second generation, cumulative (over two generations), current (for the second generation) and residual (from the first generation) genetic gains were estimated by comparing three different types of lines: SS (selected for two generation), SC (selected for the first generation only) and CC (unselected for two generations). The SS line grew significantly faster (P < 0.05) than the other two lines, indicating that the second generation selection for faster growth is still effective. Response to selection and realized heritability for the second generation were 0.612 +/- 0.101 and 0.349 +/- 0.057, respectively, which are similar to those observed for the first generation. The cumulative, current, and residual gains were 17.56 +/- 5.30%, 10.63 +/- 2.46%, and 6.25 +/- 3.13%, respectively. The sustained response to selection for the second generation observed here suggests that considerable genetic variability exists in this population and that future efforts on selective breeding are likely to be fruitful. (c) 2005 Elsevier B.V. All rights reserved.

基于介电泳的电极阵列电场仿真研究

介电泳方法被广泛地应用于微纳颗粒的分离和操纵中,实现介电泳操作的关键是设计满足所需电场分布的电极阵列。针对目前在微电极阵列设计中尚缺乏简单有效的电场解析方法的现状,提出一种基于格林公式的电极阵列电场的解析方法。首先介绍了传统介电泳和行波介电泳的概念和计算模型,分析了介电泳过程与电极上所施加的交变电压的频率和幅度的关系,然后在确立电极电势的边界条件的基础上,采用基于格林公式的电场解析方法,建立了非均匀电场的解析模型,得出不同条件下的电极阵列电场分布的仿真结果,最后利用FEMLAB有限元仿真软件对解析模型进行了对比仿真,验证了该解析模型的可行性。基于格林公式的电场解析求解方法能够有效地提高电极阵列设计中的针对性以及缩短电极设计的时间。

藏东南巨厚松散堆积体发育条件、成灾模式及防治对策——以川藏公路然乌至鲁朗段为例

The unique geologic, geomorphic and climatic conditions of southeast Tibet have made the region to develop the multi-style and frequently occurring geologic hazards, especially the collapses and landslides and debris flows along the section of Ranwu-Lulang in Sichuan-Tibet highway. However, most of those geologic hazards have close relationship with the loose accumulations. That is, the loose accumulations are the main carrier of most geologic hazards. Thereof, the huge-thick accumulations along the highway is regarded as the objective in the thesis to study the geologic background, hazarding model and mitigation methods comprehensively, based on the multi-disciplinary theories and former materials. First of all, in the paper, based on field engineering geologic investigations, the genetic type and the characteristics of spatiotemporal distribution of the huge-thick loose accumulations along the highway, have been analysized from the factors of regional geology and geomorphy and climate, as well as the coupling acting of those factors with inoculation and eruption of the loose accumulations geologic hazards. The huge-thick loose accumulations has complex genetic types and specific regulations of spatiotemporal distribution, closely controlled by the outer environment of the region. The accumulations are composed of earth and boulder, with disorder structure and poor sorting, specific forming environments and depositing conditions. And its physical and mechanic properties are greatly distinguished from rock and common earth inland. When Sichuan-Tibet highway was firstly constructed along the north bank of Purlung Tsangpo River, the huge-thick loose accumulations was cut into many high and steep slopes. Through the survey to the cut-slopes and systematic investigation to their failures, the combination of height and angle of the accumulations slope has been obtained. At the same time, the types of genetic structure of those cut-slopes are also analysized and concluded, as well as their failure models. It is studied in the paper that there are piaster, duality, multielement and complexity types in genetic structure, and rip-dump-repose, rip-shear-slip and weathering-flake types in failure models. Moreover, it is briefly introduced present engineering performance methods and techniques dealing with the deformation and failure of the accumulations cut-slope. It is also suggested that several new techniques of slope enforcement and the method of landslide and rockfall avoiding should be applied. The research of high and steep cut-slope along the highway has broadened the acknowledgement of the combination of cut-slope height and angle. Especially, the dissertation also has made the monographic studies about the geologic background and hazarding models and prevention methods of some classic but difficult accumulations geologic hazards. They are: (1) Research of the engineering geologic background of the 102 landslide group and key problems about the project of tunnel. The 102 landslide group is a famous accumulational one composed of glacial tills and glaciofuvial deposit. The tunnel project is a feasible and optional one which can solve the present plight of “sliding after just harnessing” in the 102 section. Based on the glacial geomorphy and its depositing character, distribution of seepage line, a few drillhole materials and some surveying data, the position of contact surface between gneiss and accumulations has been recognized, and the retreating velocities of three different time scales (short, medium and long term) have been approximately calculated, and the weathering thickness of gneiss has also been estimated in the paper. On the basis of above acknowledgement, new engineering geomechnic mode is established. Numerical analysis about the stability of the No.2 landslide is done by way of FLAC program, which supplies the conclusion that the landslide there develops periodically. Thereof, 4 projects of tunnel going through the landslide have been put forwards. Safety distance of the tunnel from clinohefron has been numerically analysized. (2) Research of the geologic setting and disaster model and hazard mitigation of sliding-sand-slope. From the geologic setting of talus cone, it is indicated that the sliding-sand-slope is the process of the re-transportation and re-deposit of sand under the gravity action and from the talus cone. It is the failure of the talus cone essentially. The layering structure of the sliding-sand-slope is discovered. The models of movement and failure of the sliding-sand-slope has been put forwards. The technique, “abamurus+grass-bush fence+degradable culture pan”, is suggested to enforcement and green the sliding-sand-slope. (3) Characteristics and hazarding model and disaster mitigation of debris flow. The sources of solid material of three oversize debris flows have been analysized. It is found that a large amount of moraine existing in the glacial valley and large landslide dam-break are the two important features for oversize debris flow to be taken place. The disaster models of oversize and common debris flows have been generalized respectively. The former model better interpret the event of the Yigong super-large landslide-dam breaking. The features of common debris flow along the highway section, scouring and silting and burying and impacting, are formulated carefully. It is suggested that check dam is a better engineering structure to prevent valley from steeply scouring by debris flow. Moreover, the function of check dam in enforcing the slope is numerically calculated by FLAC program. (4) Songzong ancient ice-dammed lake and its slope stability. The lacustrine profile in Songzong landslide, more than 88 meters thick, is carefully described and measured. The Optical Simulated Luminescence (OSL) ages in the bottom and top of the silty clay layer are 22.5±3.3 kaB.P., 16.1±1.7 kaB.P., respectively. It is indicated by the ages that the lacustrine deposits formed during the Last Glacial Maximum ranging from 25ka B.P. to 15ka B.P. The special characteristics of the lacustrine sediment and the ancient lake line in Songzong basin indicated that the lacustrine sediment is related to the blocking of the Purlung Tsangpo River by the glacier in Last Glacial Maximum from Dongqu valley. The characteristics of the lacustrine profile also indicate that the Songzong ice-dammed lake might run through the Last Glacial Maximum. Two dimensional numerical modeling and analysis are done to simulate the slope stability under the conditions of nature and earthquake by FLAC program. The factor of safety of the lacusrtine slope is 1.04, but it will take place horizontal flow under earthquake activity due to the liquefaction of the 18.33 m silt layer. The realign to prevent the road from landslide is suggested.

品牌属性权重判断的反应时研究

In current days, many companies have carried out their branding strategies, because strong brand usually provides confidence and reduce risks to its consumers. No matter what a brand is based on tangible products or services, it will possess the common attributes of this category, and it also has its unique attributes. Brand attribute is defined as descriptive features, which are intrinsic characteristics, values or benefits endowed by users of the product or service (Keller, 1993; Romaniuk, 2003). The researches on models of brand multi-attributes are one of the most studied areas of consumer psychology (Werbel, 1978), and attribute weight is one of its key pursuits. Marketing practitioners also paid much attention to evaluations of attributes. Because those evaluations are relevant to the competitiveness and the strategies of promotion and new product development of the company (Green & Krieger, 1995). Then, how brand attributes correlate with weight judgments? And what features the attribute judgment reaction? Especially, what will feature the attribute weight judgment process of consumer who is facing the homogeneity of brands? Enlightened by the lexical hypothesis of researches on personality traits of psychology, this study choose search engine brands as the subject and adopt reaction time, which has been introduced into multi-attributes decision making by many researchers. Researches on independence of affect and cognition and on primacy of affect have cued us that we can categorize brand attributes into informative and affective ones. Meanwhile, Park has gone further to differentiate representative and experiential with functional attributes. This classification reflects the trend of emotion-branding and brand-consumer relationship. Three parts compose the research: the survey to collect attribute words, experiment one on affective primacy and experiment two on correlation between weight judgment and reaction. The results are as follow: In experiment one, we found: (1) affect words are not rated significantly from cognitive attributes, but affect words are responded faster than cognitive ones; (2) subjects comprehend and respond in different ways to functional attribute words and to representative and experiential words. In experiment two, we fund: (1) a significant negative correlation between attributes weight judgment and reaction time; (2) affective attributes will cause faster reaction than cognitive ones; (3) the reaction time difference between functional and representative or experiential attribute is significant, but there is no different between representative and experiential. In sum, we conclude that: (1): In word comprehension and weight judgment, we observed the affective primacy, even when the affect stimulus is presented as meaningful words. (2): The negative correlation between weight judgment and reaction time suggest us that the more important of attribute, the quicker of the reaction. (3): The difference on reaction time of functional, representative and experiential reflects the trend of emotional branding.