Studies on extraction procedure and antioxidative activity of phlorotannins fromSargassum kjellmanianum

Known only in phaeophyceae, phlorotannins (brown algal polyphenols) are natural products with potential uses in pharmacology. This study yielded an extraction procedure to obtain high purity, high molecular weight phlorotannins fromSargassum kjellmanianum and revealed the characteristics of their infrared and flourescence spectra. The antioxidative activity of phlorotannins, which was about 2.6 times as strong as that of 0.02% BHT (tert-butyl-4-hydroxytoluene), showed potential for preventing oil rancidification. Contribution No. 2918 from the Institute of Oceanology, Chinese Academy of Sciences. The project was supported by The State Ninth-five Key Program of China. (No. 96-916-04-01).     

Optimization of the microwave-assisted extraction of phlorotannins from Saccharina japonica Aresch and evaluation of the inhibitory effects of phlorotannin-containing extracts on HepG2 cancer cells

The use of a microwave-assisted extraction(MAE) method for the extraction of phlorotannins from Saccharina japonica Aresch(S.japonica) has been evaluated with particular emphasis on the influential parameters,including the ethanol concentration,solid/liquid ratio,extraction time,extraction temperature,and microwave power.The MAE procedure was optimized using single-factor design and orthogonal array design(OAD).The content of total phlorotannins in S.japonica was determined using a Folin-Ciocalteu(FC) assay.A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant(mg PGE/g DW) was obtained using the optimized model,which included an ethanol concentration of 55%,solid/liquid ratio of 1:8,extraction time of 25 min,irradiation power of 400 W,and temperature of 60°C.Under similar conditions,the application of a conventional extraction method led to a lower phlorotannin yield of 0.585 mg PGE/g WD.These results demonstrated that the MAE approach provided better results for the extraction of phlorotannins from S.japonica and was a promising technique for the extraction of phenolic compounds from S.japonica and other materials.In addition,screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells(HepG2) by inducing their apoptosis.The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining.     

基于伪纯像元的精度评价策略及其应用

土地覆被是地球科学研究中的重要参量,评价土地覆被数据的制图精度是保障数据合理使用的前提。本文提出了一种基于伪纯像元的精度评价策略（伪纯像元策略）,即当低空间分辨率栅格窗口内对应的高空间分辨率数据中优势类别（面积最大的地类）的占比高于伪纯像元纯度阈值（代表像元纯度,取值范围：35%~100%,步长为5%）时,以此栅格窗口为基准生成土地覆被类型为优势类别的伪纯像元用于精度评价。以澜沧江-湄公河（澜湄）流域为试验区,选择GlobeLand30为参考数据,并基于混淆矩阵精度评价方法对比分析了伪纯像元策略与重采样法（最近邻法和众数法）在CCI-LC（300 m）和MCD12Q1（500 m） 2套全球土地覆被数据精度评价中的差异。结果表明：① 伪纯像元策略在35%~100%纯度阈值下对CCI-LC和MCD12Q1在澜湄流域评价的精度分别为72.76%~55.26%和71.44%~45.41%,比重采样法评价的单一精度（众数法：71.21%和70.54%、最近邻法：71.48和69.87%）能更好地反映像元纯度对土地覆被数据精度的影响;② CCI-LC的总体精度高于MCD12Q1,且2套数据的精度差随纯度阈值的增大而增加,CCI-LC和MCD12Q1在35%、100%纯度阈值下的精度差分别为1.32%和9.85%;③ 2套数据中耕地、有林地、草地和水体的分类精度均相对较高,而灌木林地（精度接近0）和裸地的分类精度均较低;④ 2套数据与GlobeLand30的空间不一致区域多出现在土地覆被类型高度异质化的混合像元区域,且随纯度阈值的增大,评价样本栅格更趋均质,混合像元对评价精度的影响也会递减。伪纯像元精度评价策略适用于跨空间分辨率土地覆被数据的精度对比,为评价全球土地覆被产品在区域尺度的适用性及适用范围提供了新的检验策略。     

Inhibitory effects and mechanisms of high molecular-weight phlorotannins from <Emphasis Type="Italic">Sargassum thunbergii</Emphasis> on ADP-induced platelet aggregation

We evaluated the effects of high molecular-weight phlorotannins from Sargassum thunbergii(STP) on ADP-induced platelet aggregation and arachidonic acid(AA) metabolism in New Zealand white rabbits and Wistar rats.The inhibition of STP on platelet aggregation was investigated using a turbidimetric method,and the levels of the terminal products of AA metabolism were measured using the corresponding kits for maleic dialdehyde(MDA),thromboxane B2(TXB2) and 6-keto-prostaglandin F1α(6-keto-PGF1α) by colorimetry an...     

Purification and photodynamic bioactivity of phycoerythrin and phycocyanin from Porphyra yezoensis Ueda

Phycoerythrin and phycocyanin were purified from Porphyra yezoensis Ueda with their bioactivity determined in this study. Continuous precipitation with ammonium sulfate at different concentrations （10%, 20%, 40%and 50%） increased the purity （A564：A280） of phycoerythrin to 1.49, 3.92 fold of the raw extract （0.38） and the purity （A615：A280） of phycocyanin to 0.70, 3.33 fold of the raw extract （0.21）. Two more times of chromatography with hydroxylapatites finally made the purity of phycoerythrin and phy-cocyanin reach 5.50, 14.47 fold of the raw extract, and 5.10, 24.29 fold of the raw extract, respectviely. The yield of high purity phycoerythrin and phycocyanin were 0.21%and 0.09%of dried P. yezoensis blade, respectively. The photodynamic cytotoxic ex-periment showed that both phycoerythrin and phycocyanin inhibited the growth of liver tumor cells significantly. It was found that 250 mg L-1 purified phycoerythrin and phycocyanin inhibited the growth of hepatocellular carcinoma cells 24 h after laser-irradiation by 80%and 59%, respectively, and 100 mg L-1 purified phycoerythrin and phycocyanin induced the apoptosis of 31.54%and 32.54%of the cells, respectively, 8 h after photodynamic therapy. Oue findings demonstrated that P. yezoensis can serve as photosensitizer （phycoerythrin and phycocyanin） producer.     

Improvement of Urban Impervious Surface Estimation in Shanghai Using Landsat7 ETM＋ Data

This paper explores the potential to improve the impervious surface estimation accuracy using a multi-stage approach on the basis of vegetation-impervious surface-soil (V-I-S) model. In the first stage of Spectral Mixture Analysis (SMA) process, pixel purity index, a quantitative index for defining endmember quality, and a 3-dimensional endmember selection method were applied to refining endmembers. In the second stage, instead of obtaining impervious surface fraction by adding high and low albedo fractions directly, a linear regression model was built between impervious surface and high/low albedo using a random sampling method. The urban impervious surface distribution in the urban central area of Shanghai was predicted by the linear regression model. Estimation accuracy of spectral mixture analysis and impervious surface fraction were assessed using root mean square (RMS) and color aerial photography respectively. In comparison with three different research methods, this improved estimation method has a higher overall accuracy than traditional Linear Spectral Mixture Analysis (LSMA) method and the normalized SMA model both in root mean square error (RMSE) and standard error (SE). However, the model has a tendency to overestimate the impervious surface distribution. Foundation item: Under the auspices of National Natural Science Foundation of China (No. 40701177)     

Enzymatic synthesis of methyl-galactoaldehyde

Methyl-galactosides were oxidized at room temperature by galactose oxidase in a one-step reaction and afforded methyl-galactoaldehyde in excellent yield and high purity. The resulting galactoaldehyde as a useful intermediate can be directly used in glycopeptide synthesis.     

Geological and geochemical prediction on deeply-seated ore-bodies in Haigou gold deposit of Jilin，China

Lode 28 is the largest gold-bearing quartz vein in Haigou gold deposit,and the lode itself contains more than 30t of gold. Geochemical study shows that 12 trace elements related gold mineralization can be divided into 5 metallogenic factors(element assemblages) .The high values of F1,F2 and F4 together indicate overlapped of multiple stages of gold mineralization,revealing high potential of gold mineralization at depth;the single high value of F4 represents the root of an existing ore body while high values of F3 and F4 show the intervals of barren sectors in the lode. Comprehensive geochemical studies show the high prospection potential below the 14th level and between lines 39-71. It is also prospective to look for blind ore-bodies between lines 15-29 and below the 10th level.     

Antiviral Effects of Stichopus japonicus Acid Mucopolysaccharide on Hepatitis B Virus Transgenic Mice

Hepatitis B virus(HBV) is a significant global pathogen and efficient cure for HBV patients is still a challenging goal. We previously reported that acidic mucopolysaccharide from stichopus japonicus selenka(SJAMP) could inhibit HBs Ag and HBe Ag expression in vitro. However, the potential anti-HBV effects of SJAMP in vivo have not yet been explored. In this study, we show that SJAMP exhibits potent anti-HBV activity in HBV transgenic mice in a dose-dependent manner. Specifically, sixty HBV transgenic male BALB/c mice were randomly selected to receive the treatment of PBS, low dose SJAMP(30 mg kg~(-1)), middle dose SJAMP(40 mg kg~(-1)), high dose SJAMP(50 mg kg~(-1)) and IFN(45 IU kg~(-1)) for 30 d. SJAMP treatment suppressed serum HBV-DNA, and liver HBs Ag and HBc Ag levels in HBV-transgenic mice. The present study highlights the potential application of SJAMP in HBV therapy.     

Functional characterization of a novel microbial esterase identified from the Indian Ocean and its use in the stereoselective preparation of (<Emphasis Type="Italic">R</Emphasis>)-methyl mandelate

Genomic mining has identified a novel microbial alkaline esterase from the Indian Ocean. This esterase was overexpressed in E. coli BL21 (DE3) and further functionally characterized. Under optimal conditions (10 mmol/L substrate, pH 6.0, 2 h at 40 °C), this esterase can hydrolyze racemic methyl mandelate to (R)-methyl mandelate with very high optical purity (e.e. >99%) and yield (nearly 90%). Interestingly, the stereoselectivity of this esterase is opposite to that of two previously reported lipases that can generate (S)-methyl mandelate through the hydrolysis of racemic methyl mandelate. No organic solvents or other additives were required to optimize the optical purity and production of the final chiral product (R)-methyl mandelate, which can potentially simplify the production procedure of (R)-methyl mandelate catalyzed by esterase.     

不同保存条件下鱼类组织基因组DNA的提取效果分析

对-20℃下冰冻,常温下酒精、甲醛溶液和Bouin氏液等保存条件下的鱼体组织(血液、肌肉、鳞片、鳍条)的DNA提取方法作了比较,并经琼脂糖凝胶电泳、紫外分光光度计检测及RAPD扩增结果验证。结果表明,除鳞片外,新鲜组织、-20℃冰冻组织以常规方法可提取出较高质量的DNA;保存于70%酒精或10%甲醛溶液中的组织,经预处理,亦可得高质量DNA;新鲜、冰冻、70%酒精或短时间10%甲醛固定的鳞片经适当预处理也可提取出较高质量的DNA。     

Anti-proliferative activity of phlorotannin extracts from brown algae Laminaria japonica Aresch

In this study, we evaluated the anti-proliferative activity of phlorotannins derived from brown algae Laminaria japonica Aresch extracts on the human hepatocellular carcinoma cell (BEL-7402) and on murine leukemic cells (P388) by MTT assay. Cells were incubated with 100 μg/mL of the phlorotannin extract (PE) for 48 h. The inhibitory rate of PE on BEL-7402 and P388 cells was 30.20±1.16% and 43.44±1.86%, respectively, and the half-inhibitory concentration of PE (IC₅₀) on P388 and BEL-7402 cells was 120 μg/mL and >200 μg/mL, respectively. Microscopic observation shows that the morphologic features of tumor cells treated with PE and 5-fluorouracil are markedly different from the normal control group. The inhibitory rate of fraction A₂ isolated from PE by sephadex LH-20 for BEL-7402 and P388 cells at the sample concentration of 70.42 μg/mL was 61.96±7.02% and 40.47±8.70%, respectively. The apoptosis peak for fraction A₂ was the most profound of all fractions used in the flow cytometry assay. The results indicate that the anti-proliferative of this algal extract is associated with the total phlorotannin content.     

Preparation and characteristics of biosilica derived from marine diatom biomass of Nitzschia closterium and Thalassiosira

In this study, biosilica of high purity was successfully prepared from marine diatom( Nitzschia closterium and Thalassiosira) biomass using an optimized novel method with acid washing treatment followed by thermal treatment of the biomass. The optimal condition of the method was 2% diluted HCl washing and baking at 600°C. The SiO_2 contents of N. closterium biosilica and Thalassiosira biosilica were 92.23% and 91.52%, respectively, which were both higher than that of diatomite biosilica. The SiO_2 morphologies of both biosilica are typical amorphous silica. Besides, N. closterium biosilica possessed micropores and fibers with a surface area of 59.81 m~2/g. And Thalassiosira biosilica possessed a mesoporous hierarchical skeleton with a surface area of 9.91 m~2/g. The results suggest that the biosilica samples obtained in this study present highly porous structures. The prepared porous biosilica material possesses great potential to be used as drug delivery carrier, biosensor, biocatalyst as well as adsorbent in the future.     

Isolation of Chloroplasts from Marine Microalga Isochrysis galbana Parke for Their Lipid Composition Analysis

Marine microalga Isochrysis galbana is an important feed species with a high nutritional value.Different from other uni-cellular algae,its cell contains two chloroplasts which are the major sites for lipid synthesis.Here,we optimized a chloroplast isola-tion approach suitable for the isolation of I.galbana chloroplasts and determined the purity and integrity of the isolated chloroplasts through microscopic observations and enzyme activity assay.The chloroplast lipids were analyzed with a ultrahigh-performance li-quid chromatography-Q Exactive Orbitrap-mass spectrometry.This newly developed isolation approach is simple and reliable to isolate chloroplasts with high integrity and purity.The average yield of intact chloroplasts was 15.3%±0.1%.Glycolipids and acyl-glycerols were the main chloroplast lipids.Glycolipids accounted for 56.6%of chloroplast lipid.Digalactosyldiacylglycerol(DGDG),monogalactosyldiacylglycerol(MGDG)and sulfoquinovosyldiacylglycerol(SQDG)were the main glyceroglycolipids.The fatty acyl R1/R2 were mostly 18:4/16:1,18:3/16:1 and 18:4/18:5 in DGDGs,14:0/18:4,18:4/18:5,18:4/18:4 and 18:3/18:4 in MGDGs and 16:0/14:0,16:0/18:3,and 18:4/18:3 in SQDGs.In addition,diacylglycerol(DAG)was the most abundant acylglycerols;the content of 22:6/18:4-DAG was the highest.There was a little amount of glycosphingolipid(GSL)in chloroplast.Digalactosylmonoglyceride(DGMG),monogalactosylmonoglyceride(MGMG),sulfoquinovosylmonoacylglycerol(SQMG),monoglyceride(MAG),phospholi-pids(PLs),ceramide(Cer)and betaine lipids were nearly undetectable in chloroplast.The fatty acid proportions of DGDGs,MGDGs,SQDGs,DAGs,triglycerides(TAGs)and GSLs were either higher or lower than or similar to those of whole-cell.Collectively,our isolation approach is applicable to many aspects of chloroplast biology,and may offer a reference for the isolation of chloroplasts from other marine microalgae.     

地球自转和固体潮对地球重力场时变特征的影响

精密和详细测定地球重力场及其时间变化，是目前卫星重力测量的主要课题。基于高精度的固体潮展开，研究了地球自转和固体潮对地球重力场时变特性的影响。给出了适合应用于潮波法的理论公式，该公式不同于IERS（92）（96）历书频谱法公式，考虑了4阶潮汐效应，精度可达到10^-11ms^-2量级。改正了IERS（96）关于永久性潮汐处理的不妥之处，即指出要用长期Love数代替固体潮Love数的理由，并利用潮汐数据进行了计算，给出了理论公式可为高精度地球重力场时变特性的研究提供理论参考和依据。     

Purification and Refolding of a Novel β-Agarase from Inclusion Body of E. coli

β-agarase AgaB appears to represent a new family of glycoside hydrolase; it is structurally and functionally different from other known agarases. In the present study, AgaB was expressed with a temperature-inducible expression system in E. coli BL21 (DE3) as a fusion protein bearing a C-terminal hexahistidine tag. The protein existed mainly in the form of inclusion body.After being washed and solubilized, AgaB in inclusion body was denatured and purified to electrophoretic purity by immobilized metal affinity chromatography. The purified AgaB was then refolded using a simple pulse dilution method, and the refolded AgaB showed a high specific hydrolysis activity of about 1600 units/mg protein. Forty milligrams of refolded pure protein were obtained from 1L of culture.     

Metabolic and physiological regulation of Chlorella sp. (Trebouxiophyceae,Chlorophyta) under nitrogen deprivation

Journal of Oceanology and Limnology - A freshwater green microalgae Chlorella sp., UMACC344 was shown to produce high lipid content and has the potential to be used as feedstock for biofuel...     

山东省地质资料电子文档的管理和利用探讨——以“焦家式”金矿地质资料信息服务集群化和产业化工作为例

电子文档具有设备依赖性强、高密度存储性和自动化程度较高等特性,在充分分析和利用这一特征的基础上,以＂焦家式＂金矿地质资料信息服务集群化和产业化工作为例,提出新时代的地质资料管理要尽快转变传统的管理模式,提升地质资料电子文档管理水平,最大程度地挖掘地质资料电子文档的内在潜力,以便使地质资料更好地为国民经济建设服务。     

DISTRIBUTION OF LEAD IN URBAN SOIL AND ITS POTENTIAL RISK IN SHENYANG CITY, CHINA

1INTRODUCTION The ubiquitous distribution and known toxicity of lead pollution in urban environment are posinggreat concern, in term of human health and environment (JULIE and ALEX, 2001). In recent years various human activities, such as automobile exhaust, waste disposal, paint, lead smelting and refining, battery disposal, as well as coal and fuel combustion have implied notable contributions to the increase of environmental lead concentration (SUTHERLAND et al., 2003). Pb is an…