Turbulent Modeling of ABL over Wavy Water Surface

A new model accounting for both turbulence and sea state effects has been proposed in this paper to describe momentum, heat and moisture exchanges through air-sea interface. While long wave components mainly change air flow profile, short wave components

In vivo study on the effects of microcystin extracts on the expression profiles of proto-oncogenes (c-fos, c-jun and c-myc) in liver, kidney and testis of male Wistar rats injected i.v. with toxins

Microcystins (MCs) are a potent liver tumor promoter, possessing potent tumor-promoting activity and weak initiating activity. Proto-oncogenes are known to be involved in the tumor-promoting mechanisms of microcystin-LR. However, few data are available on the effects of MCs oil proto-oncogenes in the whole animal. To investigate the effects of MCs on the expression profile of the proto-oncogenes in different organs, male Wistar rats were injected intravenously with microcystin extracts at a dose of 86.7 mu g MC-LR eq/kg bw (MC-LR eq, MC-LR equivalents). mRNA levels of three proto-oncogenes c-fos, c-jun and c-myc in liver, kidney and testis were analyzed using quantitative real-time PCR at several time points post-injection. Significant induction of these genes at transcriptional level was observed in the three organs. In addition, the increase of mRNA expression of all three genes was much higher in liver than in kidney and testis. Meanwhile, the protein levels of c-Fos and c-Jun were investigated by western blotting. Both proteins were induced in the three organs. However, elevations of protein levels were Much lower than those of mRNA levels. These findings suggest that the expression of c-fos, c-jun and c-myc might be one possible mechanism for the tumor-promoting activity and initiating activity of microcystins. (c) 2008 Published by Elsevier Ltd.

U19/Eaf2 knockout causes lung adenocarcinoma, B-cell lymphoma, hepatocellular carcinoma and prostatic intraepithelial neoplasia

Upregulated gene 19 (U19)/ELL-associated factor 2 (Eaf2) is a potential human tumor suppressor that exhibits frequent allelic loss and downregulation in high-grade prostate cancer. U19/Eaf2, along with its homolog Eaf1, has been reported to regulate transcriptional elongation via interaction with the eleven-nineteen lysine-rich leukemia (ELL) family of proteins. To further explore the tumor-suppressive effects of U19/Eaf2, we constructed and characterized a murine U19/Eaf2-knockout model. Homozygous or heterozygous deletion of U19/Eaf2 resulted in high rates of lung adenocarcinoma, B-cell lymphoma, hepato cellular carcinoma and prostate intraepithelial neoplasia. Within the mouse prostate, U19/Eaf2 defficiency enhanced cell proliferation and increased epithelial cell size. The knockout mice also exhibited cardiac cell hypertrophy. These data indicate a role for U19/Eaf2 in growth suppression and cell size control as well as argue for U19/Eaf2 as a novel tumor suppressor in multiple mouse tissues. The U19/Eaf2 knockout mouse also provides a unique animal model for three important cancers: lung adenocarcinoma, B-cell lymphoma and hepatocellular carcinoma.

Cyclin A2 is differentially expressed during oocyte maturation between gynogenetic silver crucian carp and gonochoristic color crucian carp

Silver crucian carp (Carassius auratus gibelio) is a unique gynogenetic fish. Because of its specific genetic background and reproduction mode, it is an intriguing model system for understanding regulatory mechanism of oocyte maturation division. It keeps its chromosomal integrity by inhibiting the first meiotic division (no extrusion of the first pole body). The spindle behavior during oocyte maturation is significantly different from that in gonochoristic fish. The chromosomes are first arranged in a tripolar spindle, and then they turn around and are reunited mutually to form a normal bipolar spindle. A new member of the fish A-type cyclin gene, cyclin A2, has been isolated by suppression of subtractive hybridization on the basis of its differential transcription in fully-grown oocytes between the gynogenetic silver crucian carp and gonochoristic color crucian carp. There are 18 differing amino acids in the total 428 residues of cyclin A2 between the two forms of crucian carps. In addition, cDNAs of cyclin A1 and cyclin B have also been cloned from them. Thus two members of A-type cyclins, cyclin A1 and cyclin A2, are demonstrated to exist in fish, just as in frog, humans, and mouse. Northern blotting reveals that cyclin A2 mRNA is more than 20-fold and cyclin A1 mRNA is about 2-fold in fully grown oocytes of gynogenetic silver crucian carp compared to gonochoristic color crucian carp. However, cyclin B does not show such a difference between them. Western blot analysis also shows that the cyclin A2 protein stockpiled in fully grown oocytes of gynogenetic crucian carp is much more abundant than in gonochoristic crucian carp. Moreover, two different cyclin A2 expression patterns during oocyte maturation have been revealed in the two closely related crucian carps. For color crucian carp, cyclin A2 protein is translated only after hormone stimulation. For silver crucian carp, cyclin A2 protein can be detected throughout the process of maturation division. The different expression of cyclin A2 may be a clue to understanding the special maturation division of gynogenetic silver crucian carp.

包头稀土工业区土壤中钍的环境化学行为

本论文分为两部分：1. 综述部分（第一章和第二章），介绍了我国包头地区稀土工业区钍污染概况，对稀土工业生产造成的放射性生态环境污染进行了分析和归纳；评述了土壤和沉积物中放射性核素污染生态物理化学研究和进展；说明了本研究课题的背景、意义和技术路线。2. 实验部分（第三章至第六章），包括以下几方面内容：土壤样品和高铁矿渣样品中钍的分析方法的建立；对土壤和矿渣样品中钍的形态进行定量分析，考察了土壤性质对土壤中钍形态分布的影响；模拟自然环境，研究钍在土壤-植物系统之间的迁移积累和钍形态的植物可利用性；土壤样品对钍的吸附-解吸行为及其影响因素。 我国包头稀土工业在稀土矿浮选和稀土精矿湿法冶炼过程中产生了大量含放射性钍的废渣、废水和粉尘，对当地生态环境造成严重的破坏和放射性污染。 采用合适内标，ICP-MS法对样品中钍分析，考察了基体干扰、记忆效应和质谱干扰，比较了不同的样品消解方法对钍测定的影响，并用标准土壤样品和标准加入法对方法的准确性进行了评价。分别采用Tessier、BCR和Martínez-Aguirre形态萃取方法对土壤和样品中钍的形态进行分析，通过对总量的回收率和萃取剂选择性比较，选择了Martínez-Aguirre连续萃取法定量样品中钍的形态，并对其进行了优化和评价。考察了土壤性质影响着钍的形态分布。 通过盆栽实验，考察了小麦对根际土壤中钍形态分布以及的在不同生长期对钍的吸收影响。利用相应的材料人工模拟了土壤中钍的形态，对模拟的钍各形态的植物可利用性和植物吸收贡献指数进行评估分析。利用不同的磷酸盐对土壤进行培养处理，考察了磷酸盐的加入对土壤中钍的生物可利用性影响。 实验了土壤样品对钍的吸附-解吸过程，通过吸附容量、分配系数和吸附百分比等参数考察土壤对钍吸附能力，并考察了被土壤吸附钍的解吸行为。通过吸附机理的分析，土壤对钍的吸附作用主要是通过Th(IV)的表面水解吸附模式进行。根据实验结果，土壤样品对溶液中钍的吸附热力学可以用Freundlich方程式来描述，吸附的动力学过程可用Elovich方程描述，并对吸附方式和吸附过程进行论述。实验发现，吸附-解吸条件、土壤性质、外源稀土元素和施肥等对土壤吸附钍有一定影响。

EDTA溶液修复重金属污染土壤的效果及金属的形态变化特征

采用0.05mol.L-1的EDTA作为萃取剂,在一定的萃取条件下,对2种尾矿土壤中重金属进行土壤柱萃取实验,并采用优化的BCR(European Community Bureau of Reference)连续萃取方案对萃取前后的Pb、Zn、Cu和Cd进行形态分析.研究EDTA对4种金属的萃取效率及萃取前后的形态变化特征.结果表明,EDTA能有效的从土壤中萃取该4种金属,萃取效率依次为:Cd>Zn>Cu>Pb;金属的4种形态均能被EDTA萃取;在浅层土壤中,EDTA对酸可提态的金属的萃取效果尤为显著;在深层土壤中,酸可提取态、氧化物结合态、有机结合态和残余态4种形态的金属萃取效果,随着土壤柱深度的增加而降低.

Simultaneous genotyping of multiplex single nucleotide polymorphisms of the K-ras gene with a home-made kit

Accurate and fast genotyping of single nucleotide polymorphisms (SNPs) is important in the human genome project. Here an automated fluorescent method that can rapidly and accurately genotype multiplex known SNPs was developed by using a homemade kit, which has lower cost but higher resolution than commercial kit. With this method, oncogene K-ras was investigated, four known SNPs of K-ras gene exon 1 in 31 coloerctal cancer patients were detected. Results indicate that mutations were present in 8(26%) of 31 patients, and most mutations were localized in codon 12. The presence of these mutations is thought to be a critical step and plays an important role in human colorectal carcinogenesisas. (C) 2003 Elsevier B.V. All rights reserved.

Evaluation of a sequential extraction for the speciation of thorium in soils from Baotou area, Inner Mongolia

Sequential extraction procedures were widely applied for speciation of radioactive elements. In this study, the sequential extraction procedure developed by Martinez-Aguirre was employed for quantification of different chemical forms of thorium in the soil. The total amount of thorium in contaminated soil was much higher by four-fold than the local background value. The soil properties affect the amount of thoriurn and distribution of fractions in contaminated soil. Results showed that the proportion of thorium in soils from Baotou was found as the residual fraction (F5 + F6) > absorbed fraction (F3), coprecipitated fraction (F4) > carbonates fraction (172) and exchangeable fraction (F1) that could be available to plants. The recovery, calculated by ratio of the sum of the six fractions to the pseudo-total content of thorium, was in the range from 96% to 110%. A comparison was carried out between the sequential extraction and the single extraction to evaluate the selectivity of the extractants. It was found that the amount of thorium of absorbed fraction (H) was higher in the single extraction than that estimated in the sequential extraction, possibly duo to transform of the labile form. While for non-residual fraction analysis, the single extraction scheme was a desirable alternative to the sequential extraction procedure.

Rhein induces apoptosis and cell cycle arrest in human hepatocellular carcinoma BEL-7402 cells

Rhein, an anthraquinone derivative of rhubarb, inhibits the proliferation of various human cancer cells. In this paper, we focused on studying the effects of rhein on human hepatocelluar carcinoma BEL-7402 cells and further understanding the underlying molecular mechanism in an effort to make the potential development of rhein in the treatment of cancers. Using MTT assay and flow cytometry, we demonstrate a critical role of rhein in the suppression of BEL-7402 cell proliferation in a concentration- and time-dependent manner. The increase of apoptosis rate was observed after incubation of BEL-7402 cells with rhein at 50-200 mu M for 48 hours, and the cells exhibit typical apoptotic features including cellular morphological change and chromatin condensation. Moreover, rhein-induced cell cycle S-phase arrest. Additionally, after rhein treatment, expression levels of c-Myc gene were decreased, while those of caspase-3 gene were increased in a dose-dependent manner by using real-time PCR assay. The results demonstrate for the first time that cell cycle S-phase arrest is one of the mechanisms of rhein in inhibition of BEL-7402 cells. Rhein plays its role by inducing cell cycle arrest via downregulation of oncogene c-Myc and apoptosis through the caspase-dependent pathway. It is expected that rhein will be effective and useful as a new agent in hepatocelluar carcinoma treatment in the future.

贵阳市郊（喀斯特地区）菜园土重金属的生物地球化学循环与绿色作物生产

随着城市化进程的快速推进，大量蔬菜等食物由农村向城市输送，因此促进了城郊结合部蔬菜基地的发展。然而，城市化发展却导致越来越严重的城市和城郊土壤和大气污染，加上现代化生产中化肥和农用化学品的大量使用等，使得重金属在菜园土中大量积累，并可能通过食物链进入人体，威胁人类身体健康。因此，对重金属在土壤－蔬菜体系间迁移的生物地球化学行为的研究是我们了解和防治蔬菜重金属污染、促进绿色作物生产和保护人类健康的关键。 本文选择世界典型喀斯特地区的贵阳市市郊的菜园土－蔬菜体系为主要研究对象，通过系统地对土壤、主要蔬菜和大气沉降物质的元素分析以及铅同位素分析，对研究区域菜园土的主要理化性质、土壤（以及剖面）和蔬菜样品中重金属Cu、Pb、Zn和Cd的含量变化、菜园土以及土壤剖面重金属的形态分布等特征进行了研究。利用微量元素地球化学以及同位素地球化学理论，并结合土壤学研究理论和方法探讨了重金属在菜园土（石灰土和黄壤）和蔬菜体系间的赋存形态、重金属元素的来源、迁移与转化规律及其中的主要控制因素。 主要研究结果认为：贵阳市郊菜园土重金属元素含量变化与土壤母质显著相关，黄壤类型菜园土处于中度污染水平，石灰土类型菜园土处于轻度污染水平。菜园土中重金属形态以残余态为主，其次为有机结合态，再次为铁锰氧化物结合态和酸可提取态。土壤剖面中，菜园土表层大多数重金属含量高于背景剖面，其余各层吻合度较高。土壤剖面中重金属的形态分布仍以残余态为主，菜园土剖面上各元素的生物可利用态即酸可提取态、氧化物结合态和有机结合态则均要高于背景剖面，Pb和Zn主要受到有机结合态的影响，而Cd则三种形态的含量均高于背景剖面，种种迹象表明人为活动增加了菜园土重金属的活性和生物有效性，且以有机结合态的改变最为显著。 蔬菜中红薯可食部位的各项重金属富集系数均大于其他蔬菜，最容易受到土壤中重金属的影响；在土壤－蔬菜体系中，重金属元素含量的分布总体特征为菜园土>根>茎叶>果实，体系内元素的迁移在土壤/蔬菜根界面上最为关键，起着控制作用，此界面上各元素的迁移系数顺序为Cd>>Cu，Zn>Pb，大多数重金属元素在黄壤类型的菜园土中的迁移系数要小于石灰土类型的；在土壤－红薯和土壤－辣椒体系中，Cd的迁移系数随土壤pH的增加而降低，而其余元素的迁移系数则随土壤pH的增加而增加；土壤主成分与土壤理化性质对重金属形态分布有显著影响，但BCR连续提取法得到的土壤中重金属元素的各生物可利用态的含量与蔬菜根部的含量相关性不大；覆膜种植方式使土壤pH由4.5降低到3.8，并改变了其它物化参数，从而影响重金属的形态分布及其在蔬菜体内的含量分布特征，极可能增加农业系统中重金属的环境风险；铅稳定同位素分析表明，土壤中的铅主要来自于母岩的风化，蔬菜中放射成因铅明显略低于菜园土，菜园土和蔬菜中铅同位素组成在208Pb/206Pb对207Pb/206Pb的分布图上呈直线分布（在菜园土－蔬菜体系中，土壤样品、蔬菜不同部位的样品、以及雨水样品的铅同位素组成的分布也形成了极好的直线），显示明显的两端元混合体系；根据各端元物质铅同位素组成计算，土壤铅对蔬菜根部、茎叶的贡献值由71.8%~77.7%降低到16.0%~45.4%之间，大气铅的贡献则沿根向茎叶和果实逐渐增加，研究结果显示大气污染对蔬菜重金属Pb的贡献不可忽视。

黔西南滥木厂铊矿化区河流沉积物重金属环境地球化学及环境效应研究

矿山环境重金属污染及其生态效应研究是环境地球化学研究的热点问题之一，其中水环境生态系统中的沉积物重金属污染由于可能影响流域水环境安全而备受关注。贵州矿产资源丰富，其开采利用过程中的重金属元素污染十分严重，尤其是Tl、As和Hg的污染备受关注。本研究选择黔西南滥木厂铊矿化区为研究对象，通过分析该地区河流沉积物中铊、砷、汞等重金属元素的环境地球化学分布特征，对重金属污染状况进行评价，并探讨其对环境的生态危害，得到以下几点认识： 1. 滥木厂铊矿化区河流沉积物中重金属Tl、Hg、As和Cd的含量相对很高。其中，Tl、Hg和As在矿山影响区河流沉积物中平均含量分别为23.3 mg/kg、46.8 mg/kg 和97.3 mg/kg，比页岩平均含量高几十倍至上百倍，而矿山未影响区及对照区河流沉积物中含量都相对较低。Cd在矿渣以及清水河矿山影响区、矿山未影响区和对照区河流沉积物中的平均含量都相对较高，分别为0.97 mg/kg、1.31 mg/kg、1.17 mg/kg和1.21 mg/kg，约为页岩平均含量的2～5倍，且变化不明显。重金属环境地球化学分析表明，Tl、Hg和As为同源污染物质，主要来自矿山硫化物的风化淋漓；Cd的高含量与矿山联系不明显，可能是由于地域上的Cd异常所致。Cu、Cr、Zn和Pb的含量都相对较低，只略高于页岩平均含量。 2. 地质累积指数（Igeo）和潜在生态危害系数（RI）分析评价结果显示，滥木厂清水河沉积物主要受到Hg、Tl、As以及Cd的污染。受矿山影响的河流沉积物中Hg和Tl的污染很严重，具有很强的潜在生态危害；As和Cd次之；Zn、Cu、Cr和Pb的污染不明显，潜在生态危害很小。 3. 沉积物中重金属各形态分级提取分析（BCR）表明，受矿山影响的滥木厂清水河沉积物及剖面沉积物中：不但总Tl含量很高，有效态Tl含量也高，平均分别为6.0 mg/kg 和5.9 mg/kg，对环境的生态危害很大；Hg虽然总含量非常高，但其酸可提取态含量都低于仪器的检测下限，可还原态含量也不高，平均分别只为0.46 mg/kg 和1.53 mg/kg，主要集中在不易释放的可氧化态和非常稳定的残余态，对环境的生态危害一般；As的总含量较高，但有效态平均含量只为6.51 mg/kg和1.58 mg/kg，对环境的生态危害较小；Cd的总含量也相对较高，有效态平均含量也分别达0.55 mg/kg和0.52 mg/kg，对环境的危害可能较大；Cr、Cu、Zn及Pb的总含量和有效态含量都较低，对环境的生态危害较小。 4. 滥木厂铊矿化区河流沉积物中Tl、Hg和Cd的重金属污染的生态危害性主要表现为Tl、Hg和Cd对食物链的直接或间接污染。Tl和Cd易在农作物中富集，Hg甲基化后也可以在农作物中富集，其人体健康危害性较大。