Exposição ao material particulado 2,5 m coletado em vias de alto tráfego da cidade do Rio de Janeiro: avaliação mutagênica, genotóxica e determinação de risco à saúde induzido por hidrocarbonetos policíclicos aromáticos

A mutagenicidade do material particulado é atribuída primeiramente aos hidrocarbonetos policíclicos aromáticos (HPA). Investigamos a atividade mutagênica do material particulado (MP2,5) em amostras coletadas em três pontos da cidade do Rio de Janeiro. As coletas foram realizadas com auxílio de um amostrador de grande volume na Avenida Brasil, no campus da Universidade do Estado do Rio de Janeiro e no Túnel Rebouças em filtros de fibra de vidro. Metade de cada filtro foi submetido à extração por sonicação com o solvente diclorometano. Seis HPA foram identificados e quantificados por cromatografia gasosa com espectrometria de massa (GC/MS). Após a análise química as concentrações dos HPA obtidos foram correlacionados ao fatores físicos, além de ser realizado avaliação de risco para cada HPA estudado. Linhagens de Salmonella typhimurium (TA98 e derivadas TA98/1.8-DNP6, YG1021 e YG1024) foram utilizadas no ensaio de mutagenicidade e tratadas (10-50 g/placa) com extrato orgânico na presença e na ausência de metabolização exógena. Células de raiz de cebola foram tratadas com extratos orgânicos nas concentrações (5-25g/mL). A alta umidade encontrada no Túnel Rebouças pode ter influenciado na deposição de cinco dos seis HPA estudados em material particulado. Além disso, em diferentes condições de tráfego, motoristas de ônibus que cruzam a Avenida Brasil e o Rebouças túnel estão expostos ao risco induzidos por HPA na ordem de 10-6. Mutagenicidade foi detectada tanto na presença quanto na ausência de metabolização, para as linhagens YG1021 e YG1024 nos três pontos, sugerindo a presença de nitro e amino derivados de HPA. As amostras do Túnel Rebouças apresentaram os maiores valores para rev/g e rev/m3. Estes resultados podem estar relacionados ao longo trajeto e a restrita ventilação. Efeito citotóxico foi detectado pelo ensaio Allium cepa nos três pontos de monitoramento. Além disso os extratos orgânicos provenientes das coletas da Avenida Brasil, UERJ e do Túnel Rebouças induziram efeito clastogênico em células de raiz de Allium cepa

Avaliação da acidez de bio-óleos obtidos pela pirólise de óleos vegetais pós-consumo

O descarte irregular do óleo vegetal pós-consumo diretamente na rede de esgoto vem causando grandes problemas para o meio ambiente. Atualmente, essa problemática tem se intensificado devido ao aumento de produção e consumo destes óleos, o que por conseqüência aumenta o despejo desordenado. No presente estudo foi realizada a obtenção do bio-óleo a partir da pirólise térmica em atmosfera de nitrogênio, a 400C, por 20 minutos, do óleo vegetal pós-consumo, provenientes das seguintes oleoginosas: soja, milho, girassol e canola. As pirólises não-catalíticas apresentaram uma geração média entre 40 e 50% de um bio-óleo, de elevado índice de acidez, 81,8 mg NaOH/g. Na pirólise catalítica, a argila ácida K10 foi o catalisador que apresentou melhor eficácia para geração de um bio-óleo de menor índice de acidez. A concentração ótima do catalisador foi de 5%(m/m), gerando 482 % de um bio-óleo com índice de acidez de 43,8 mg NaOH/g. A caracterização dos líquidos pirolíticos obtidos foi realizada através da técnica de espectrofotometria na região do infravermelho (FTIR) e cromatografia em fase gasosa acoplada a espectrômetro de massas (CG/EM) que monstraram que a trioleína, o triglicerídeo do ácido oléico, foi craqueado, gerando o hexadecanoato de octadecila e o oleato de eicosila, ésteres do respectivo ácido graxo

Estudo in vitro de derivados sintéticos da Isoniazida e da Pirazinamida sobre Leishmania (Viannia) braziliensis

As leishmanioses são um grupo de doenças causadas por protozoários do gênero Leishmania spp que afetam 98 países. No Brasil, no ano de 2013, foram relatados 3.253 casos de leishmaniose visceral e 18.226 casos de Leishmaniose Tegumentar Americana. O tratamento de primeira escolha continua sendo realizado com antimoniais pentavalentes, e em casos de insucessos os fármacos de segunda escolha são a pentamidina e a anfotericina B. Tais medicamentos causam intensos efeitos adversos e ultimamente têm surgido cepas resistentes aos mesmos. Em áreas endêmicas têm sido cada vez mais comum o surgimento da co-infecção Leishmania com Mycobacterium tuberculosis. O tratamento para a tuberculose com pirazinamida (PZA) e isoniazida (INZ), controla a leishmaniose. Esses dados sugerem atividade anti-leishmania da PZA e da INZ. O objetivo deste trabalho foi avaliar a atividade in vitro da INZ e da PZA e seus compostos derivados (série G e série R, respectivamente) sobre Leishmania (Viannia) braziliensis. As moléculas foram testadas em monocamadas de macrófagos peritoneais de camunongos infectados com L. (V) braziliensis durante 48h. Todas as moléculas testadas inibiram o índice de infecção de forma dose dependente em comparação aos controles. As moléculas da série R foram mais ativas do que a PZA, porém o resultado foi significativo somente para a R02 (p < 0,005). Apenas a molécula R05 (76,64M) foi relativamente tóxica para macrófagos. Os compostos mais ativos foram R02, G01 e G02, cujos índices de seletividade foram 14,31, 19 e 30, respectivamente. A dosagem de nitrito foi feita em sobrenadantes de monocamadas de macrófagos peritoniais infectados e tratados com as substâncias nas concentrações 10 e 100M. A G01 e a G02 estimularam a produção de NO2 nas duas concentrações, entretanto o resultado foi estatisticamente significativo para a G02 em 100M (p < 0,0001), a G05 só estimulou óxido nítrico na maior concentração. Todos os compostos da série R estimularam NO2, contudo, o resultado foi estatisticamente significativo para a R03 e R05 a 100M (p < 0,001). Adicionalmente, foi realizado uma análise preditiva in sílico de parâmetros farmacocinéticos das moléculas mais ativas in vitro, utilizando o software admetSAR. Os dados obtidos mostraram que de forma semelhante às suas moléculas originais a G01, G02 e R02 apresentaram alta capacidade de serem absorvidas pelo trato gastrointestinal, baixo potencial hepatotoxico e carcinogênico. Juntos, esses dados demonstram que essas moléculas são seletivamente tóxicas para o parasito com potencial para serem testadas pela via oral em estudos em modelo experimental de infecção.

噬菌体434单链阻遏蛋白的高亲和力DNA结合序列的设计和筛选

一． 设计和筛选单链阻遏蛋白的高亲和力DNA结合序列 　　单链阻遏蛋白RRTRES是噬菌体434阻遏蛋白的衍生物，它是噬菌体434阻 遏蛋白的N端DBD(1-69位氨基酸)组成的共价二聚体。这个单链分子有两个DBD，一个是野生型噬菌体434的DBD-R，另一个是突变了的DBD - RTRES，二者用重组接头以头接尾的方式连接起来。在RTRES的α3-螺旋中．1、1、2、5位氨基酸与DNA识别紧密相关，它们分别为T、R、E、S。为了筛选出突变的RTRES的DNA结合位点，设计了核心序列为CATACAAGAAAGNNNNNNTTTATG随机DNA库，通过RRTRES与随机DNA库的体外结合和循环筛选。将筛选到的群体克隆并测序。通过与单链阻遏蛋白RRTRES的亲和力测定，对每一个筛选到的序列进行特性分析。结果表明，当结合位点（上述划线部分）为TTAC或TTCC时为最适操纵区序列。它们与单链阻遏蛋白RRTRES的亲和力很高，Kd值在1-10pM的范围。其中随机部分为TTTACG的操纵区与RRTRES的亲和力最高，Kd值约为lpM;当结合位点为TTAC时，平均Kd值为3pM：当结合位点为 TTCC时，Kd值在5-lOpM之间。天然噬菌体434阻遏蛋白与其操纵区的亲和力的Kd值在nM数量级，与之相比，所筛选操纵区的亲和力明显提高。此外，亲和力大小还受到结合位点两侧的碱基的影响，特别是5'位碱基的影响。 　　表达纯化同源双突变的单链阻遏蛋白RTRESRTRE'根据RTRES的以上识别特一点，设计了一系列新的操纵区序列，它们的共有序列为GTAAGAAARNTTACN，或GGAAGAAARNTTCCN，并测定它们与RTRES RTRE之间的结合特异性。结果表明，它们可被RTRES RTRES特异识别，且亲和力也很高，Kd值在5-40pM之间。其中GTAAGAAAGTTTACG与RTRES RTRES之间结合的Kd值约为5pM。同样，表达了异源双突变的单链阻遏蛋白R*RTRES，然而它与 设计的相关操纵区的亲和力并不很高，Kd值约为lOOpM。利用本工作中的随机筛选和合理设计的原则，得到了新的具有特异性识别和高亲和力的蛋白一DNA相互作用。这个方法可望用于其他DBP的新的结合特异性的筛选。 二． 非同位素的方法筛选单链阻遏蛋白的最佳DNA结合序列初探 　　克隆和表达了带半胱氨酸尾的单链阻遏蛋白，利用已包被了马来酰胺的活性板可以与自由巯基结合的特性，将蛋白固定在活性板表面。体外筛选RTRES RTRES的最佳DNA结合序列，得到了一些与RTRES RTRES结合的序列，但Kd值nM数量级。此方法需进一步优化。

Distributed maximum likelihood for simultaneous self-localization and tracking in sensor networks

We show that the sensor self-localization problem can be cast as a static parameter estimation problem for Hidden Markov Models and we implement fully decentralized versions of the Recursive Maximum Likelihood and on-line Expectation-Maximization algorithms to localize the sensor network simultaneously with target tracking. For linear Gaussian models, our algorithms can be implemented exactly using a distributed version of the Kalman filter and a novel message passing algorithm. The latter allows each node to compute the local derivatives of the likelihood or the sufficient statistics needed for Expectation-Maximization. In the non-linear case, a solution based on local linearization in the spirit of the Extended Kalman Filter is proposed. In numerical examples we demonstrate that the developed algorithms are able to learn the localization parameters. © 2012 IEEE.

Efficient decoding with generative score-spaces using the expectation semiring

State-of-the-art speech recognisers are usually based on hidden Markov models (HMMs). They model a hidden symbol sequence with a Markov process, with the observations independent given that sequence. These assumptions yield efficient algorithms, but limit the power of the model. An alternative model that allows a wide range of features, including word- and phone-level features, is a log-linear model. To handle, for example, word-level variable-length features, the original feature vectors must be segmented into words. Thus, decoding must find the optimal combination of segmentation of the utterance into words and word sequence. Features must therefore be extracted for each possible segment of audio. For many types of features, this becomes slow. In this paper, long-span features are derived from the likelihoods of word HMMs. Derivatives of the log-likelihoods, which break the Markov assumption, are appended. Previously, decoding with this model took cubic time in the length of the sequence, and longer for higher-order derivatives. This paper shows how to decode in quadratic time. © 2013 IEEE.

Novel biodiesel production technology from soybean soapstock

This paper describes an attractive method to make biodiesel from soybean soapstock (SS). A novel recovery technology of acid oil (AO) from SS has been developed with only sulfuric acid solution under the ambient temperature (25 +/- 2 degrees C). After drying, AO contained 50.0% FFA, 15.5% TAG 6.9% DAG 3.1% MAG 0.8% water and other inert materials. The recovery yield of AO was about 97% (w/w) based on the total fatty acids of the SS. The acid oil could be directly converted into biodiesel at 95 degrees C in a pressurized reactor within 5 hours. Optimal esterification conditions were determined to be a weight ratio of 1 : 1.5 : 0.1 of AO/methanol/sulfuric acid. Higher reaction temperature helps to shorten the reaction time and requires less catalyst and methanol. Ester content of the biodiesel derived from AO through one-step acid catalyzed reaction is around 92%. After distillation, the purity of the biodiesel produced from AO is 97.6% which meets the Biodiesel Specification of Korea. The yield of purified biodiesel was 94% (w/w) based on the total fatty acids of the soapstock.

厚朴中α-葡萄糖苷酶抑制活性成分研究

本论文由三章组成。 第一章是关于厚朴中具有α-葡萄糖苷酶抑制活性成分的研究。凹叶厚朴的乙醇提取物显示了较强的α-葡萄糖苷酶抑制活性。为了确定其活性成分，在活性测试的指导下，通过溶剂萃取、树脂吸附和反复硅胶柱层析等分离方法从凹叶厚朴乙醇提取物中分离得到6 个生物碱，并用质谱和核磁共振等波谱方法分别鉴定为：木兰箭毒碱，木兰花碱，鹅掌楸碱，蕃荔枝碱，罗默碱和Lysicamine。应用小肠α-葡萄糖苷酶模型测定了它们对α-葡萄糖苷酶的抑制作用。其中，番荔枝碱和木兰箭毒碱对α-葡萄糖苷酶相对抑制活性最好，分别为60%和62%；其它四个生物碱成分对α-葡萄糖苷酶的抑制活性几乎相当，鹅掌楸碱为46%，罗默碱为51%，Lysicamine 为49%，木兰花碱为51%。 第二章报道了厚朴酚的衍生物及其对α-葡萄糖苷酶的抑制活性。根据糖苷酶抑制剂的结构特点，设计合成了一系列厚朴酚的衍生物。厚朴酚经过Mannich 反应和环氧化及开环反应制备了一系列衍生物，经活性测试发现衍生物活性与取代基关系较大，其中5,5′-diallyl-3-((bis(2-hydroxyethyl)amino)methyl)biphenyl-2,2′-diol 的抑制活性最高，为72%。 第三章综述了厚朴的化学成分及药理活性两个方面的研究进展。 The dissertation consists of three chapters. The first chapter is about the study on the constituents with α-glycosidase inhibitory activity from Magnolia officinalis. The EtOH extracts of M. officinalis Rehd. et Wils showed good inhibitory activity against α-Glucosidase. In order to determine the active compounds, bio-assay was used to guide the isolation. Six known alkaloids were isolated by solvent extraction and repeated silica gel column chromatography, and their structures were identified as liriodenine, anonaine, roemerine, lysicamine, magnoflorine and magnocurarine by spectroscopic methods. The inhibitory activity against α-Glucosidase of these alkaloids was measured with alvine screening model of α-glucosidase. Among them, lysicamine and liriodenine have the best inhibitory activity at 60% and 62%, respectively. The other four alkaloids have close inhibitory activity, from 46% to 51%. The second chapter is about the derivation of magnolol and the inhibitory a ctivity of the derivatives. Seven derivatives of magnolol were prepared by Manni-ch reaction, epoxidation followed by ring-opening reaction. Biological activity as say indicated the inhibitory activity was related to substituting groups. Among them, 5,5′-diallyl-3-((bis(2-hydroxyethyl)amino)methyl)biphenyl-2,2′-diol had the highest activity at 72%. The third chapter is a review on the progress of M. officinalis including chemical constituents and pharmacological activity.

齐墩果酸的微生物转化

齐墩果酸（OA）是一个分布广泛、含量丰富的天然三萜化合物，常以皂苷元的形式广泛存在于植物中,具有多种重要生物活性。但是OA许多活性较弱，且生物利用度低，限制了其在临床上的应用。一是OA水溶性差;二是抗癌活性仍与临床应用的抗癌药物相差比较大。 真菌在微生物转化中具有种类多、培养条件比较简单等特点，为了寻找到具有转化OA能力的菌株，采取一步发酵的方法，在18株实验室保藏真菌菌株中筛选到5株目的菌株,TLC分析显示有转化效果。 随后采用二步发酵的方法作为复筛，验证5株菌株转化能力，波谱分析结果表明5株菌株对OA确实有转化作用。 选择5株菌种中代号1F-2 2菌株作为放大实验菌株，分离转化产物，得到OA衍生物108（相对分子量414m/z）和1010（相对分子量340 m/z），分离出的产物用于活性检测。寻找到产物108的RP-HPLC分离条件，质谱得出二者相对分子质量。 为验证OA转化产物抗肿瘤活性，首次研究了OA对卵巢癌细胞株IGROV1和人乳腺癌细胞株MDA-MB-231作用，通过细胞增殖抑制实验、用MTT法检测细胞活性，结果表明齐墩果酸可降低卵巢癌细胞株IGROV1和乳腺癌细胞MDA-MB-231细胞增殖能力并呈剂量依赖性，对肿瘤细胞株的半数有效抑制浓度化IC50 分别为36.58μg/mL和38.8μg/mL (P<0．01)。OA能抑制肿瘤细胞活性，并且OA对卵巢癌细胞株IGROV1抑制活性高于乳腺癌细胞MDA-MB-231。 在此基础上，转化产物108和1010对卵巢癌细胞株IGROV1和人乳腺癌细胞株MDA-MB-231的抑制作用也进行研究，MTT实验结果表明，转化产物对两株癌细胞也有抑制活性（P<0．01）。 总之，本文工作为进一步开展齐墩果酸类化合物结构改造和抗肿瘤活性的研究奠定了基础。 Oleanolic acid (OA) is a triterpenoid widely distributed in the nature which possesses various important bioactivities. OA also serves as aglycon of many natural saponins. However, the relatively weak activities and poor bioavailability hinder its clinical use. Firstly, poor water-solubility results in worse bioavailability. Secondly, compared with clinical antitumor drug, the antitumor effect of OA has a great difference, it is worse. Many fungi have ability to transform nature products into a variety of derivatives, and transformation conditions of fungi are simple. Attempt to obtain fungi strains able to biotransform OA, we carried out the following experiments: To investigate the biotransformation 0f OA by strains supplied firstly, we used one-step fermentation method to screen the aimed strains from 18 fungus strains stored in our laboratory. On the basis of the initial screening experiments, we found 5 aimed strains. The TLC results showed that the 5 fungi strains could transform OA into other components derivatives. Then we used two-step fermentation method as secondly screening. We repeated the five strains to do the experiments, analytical data of the results proved the transformation indeed. In the followed experiments work, we chose 1F-2 2 strain as large-scale transformation fungus from the aimed fungi. We got two biotransformation products of OA by 1F-2 2, and named those derivatives 108 and 1010. We found RP-HPLC separation conditions of product 108. The two products were characterized by ESI-MS. To verify the anti-tumor activity of biotransformation products of OA, we studied the inhibition effect of oleanolic acid on the ovarian carcinomas IGROV1 and breast cancer cell line MDA-MB-231 firstly. With an assay based on a tetrazolium dye (MTT), the effects of various concentrations of oleanolic acid on ovarian carcinomas IGROV1 and breast cancer cell line MDA-MB-231 were studied. MTT method was used to measure the tumor cells viability. Compared with the control group, oleanolic acid can significantly inhibit the viability of the ovarian carcinoma cells IGROV1 and MDA-MB-231 breast cancer cell line (P<0．01), IC50 values were 36.58μg/mL or 38.8μg/mL. Oleanolic acid can inhibit the malignant tumor cells viability, and inhibitory activity of OA to ovarian carcinomas IGROV1 was higher than to breast cancer cell line MDA-MB-231. On this basis, we studied the anti-tumor activity of the two derivatives of OA [called 108 (414 m/z) and 1010(340 m/z)]. It came to the conclusion that the two derivatives also showed potent inhibitory effect on the growth of these tumor cells（P<0．01）. Therefore, the results of studies will benefit the further investigating on the relationships of structures and antitumor activities of OA.

Investigation on the Voltammetric Behaviors in Planar Bilayer Lipid Membranes

In the TCNQ-modified BLM, the voltammetric response is different due to the different methods used to prepare the membrane forming solution. The direct and indirect dissolved methods result in irreversible and reversible responses respectively. These results can be explained by the different styles of the orientation of TCNQ in the membrane. The reversible response is controlled by the diffusion of electroactive species in the interior of the membrane. When MB is used to modify the BLM, very complex voltammograms are obtained. The intersection of the voltammetric curves can be regarded to be owing to the appearance of new phase in the membrane caused by MB. But it disappears at lower scan rate. Peak current increases with decreasing scan rate. This indicates that the resistance of the membrane at lower scan rate is lower than that at higher scan rate. Asymmetric curve of MB incorporated BLM is ascribed to the different rates of redox reaction at the two membrane/solution interfaces.

Quantitative structure-property relationships for colour reagents and their colour reactions with cerium using computational neural networks

Quantitative structure-activity/property relationships (QSAR/QSPR) studies have been exploited extensively in the designs of drugs and pesticides, but few such studies have been applied to the design of colour reagents. In this work, the topological indices A(x1)-A(x3) suggested in this laboratory were applied to multivariate analysis in structure-property studies. The topological indices of 43 phosphone bisazo derivatives of chromotropic acid were calculated. The structure-property relationships between colour reagents and their colour reactions with cerium were studied using A(x1-Ax3) indices with satisfactory results. The purpose of this work was to establish whether QSAR can be used to predict the contrasts of colour reactions and in the longer term to be a helpful tool in colour reagent design.

Quantitative structure-property relationships for colour reagents and their colour reactions with ytterbium using regression analysis and computational neural networks

In this paper, the new topological indices A(x1)-A(x3) suggested in our laboratory and molecular connectivity indices have been applied to multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphono bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between colour reagents and their colour reactions with ytterbium have been studied by A(x1)-A(x3) indices and molecular connectivity indices with satisfactory results. Multiple regression analysis and neural networks were employed simultaneously in this study.

壳寡糖及其新型衍生物的制备和抗肿瘤活性初步研究

壳聚糖具有多种生物活性且无毒、无污染，可生物降解，但分子量大，水溶性差，其应用受到很大限制。壳寡糖具有良好的水溶性，其制备方法和应用近年来成为研究的热点。本论文详细研究了酶法和化学法制备壳寡糖的工艺条件，并对酶降解和化学氧化降解的产物进行了比较，结果表明氧化降解的壳寡糖氨基含量有所下降，而酶法降解的产物氨基含量基本没有变化。研究发现在木瓜蛋白酶中加入Vc可以一定程度上降低降解产物的粘度。对几种酶联合降解效果进行了研究，结果表明三种酶的联合降解可得到分子量为1800左右的壳寡糖产物，同时可获得较高产率。 本论文还制备了三种新型壳寡糖衍生物，并研究了壳寡糖和三种衍生物的抗肿瘤活性。通过在壳寡糖上引入胍基乙酸，首次合成了壳寡糖胍基乙酰衍生物(N-2-胍基乙酰-壳寡糖)；引入烟酰氯、烟酰异硫氰酸酯合成了(N-2-烟酰-壳寡糖、N-2-烟酰异硫氰酸酯-壳寡糖)。 通过对BEL•7402肝癌细胞进行了抑制肿瘤活性研究表明：烟酰壳寡糖衍生物的抗肿瘤活性较其他两种衍生物和壳寡糖的活性要好(1mg/ml浓度下抑制率为21.54%)，在较低浓度下有一定的抑制活性（50ug/ml浓度下抑制率为3.57%）。随着浓度的升高，抑制活性也随之提高。烟酰异硫氰酸酯壳寡糖衍生物和胍基乙酰壳寡糖衍生物在低浓度条件下对肿瘤细胞基本没有抑制活性，在高浓度条件下有一定的抑制活性。

含硫、磷壳聚糖新衍生物的制备、结构与抑菌活性关系研究

由于化学农药和抗生素兽药残留问题严重影响着环境和人类健康，生物农药和兽药的开发迫在眉睫。壳聚糖无毒、无污染、可生物降解，已经成为这一方向研究热点。但是，目前对壳聚糖抑菌活性的研究大都集中于分子量和脱乙酰度对其活性的影响，而对壳聚糖衍生物的研究相对较少。本文制备了壳聚糖磺酰胺类、酰基异硫氰酸酯类和α-氨基烷基膦酸酯类共计40余种新型壳聚糖含硫、磷衍生物，研究了它们对6种真菌（棉花枯萎病菌、番茄早疫病菌、葡萄炭疽病菌、姜叶斑点病菌、黄瓜灰霉病菌、芦笋茎枯病）和4种细菌（大肠杆菌、绿脓杆菌、金黄色葡萄球菌、八叠球菌）的抑菌活性，结果发现，所有衍生物的抑菌活性均强于壳聚糖原料，其中4种新型衍生物对于真菌具有较强抑制活性，其抑制率大于或接近阳性对照武夷菌素；10余种衍生物对于细菌有较强的杀菌、抑菌活性，如4-HBSA(l)CMCS、4-HBSA(l)CSS等对四种细菌具有广谱性，效果接近甚至强于阳性对照诺氟沙星。 对影响因素、构效关系和机理进行了深入探讨。衍生物的分子量、浓度、溶解性、α-位C原子空间位阻、吸电子空间诱导效应、烷基链的增长、等因素变化均会对抑菌活性产生重大影响。

地幔对流理论及其在解释地球物理观测的应用

With the improving of mantle convection theory, the developing of computing method and increasing of the measurement data, we can numerically simulate more clearly about the effects on some geophysical observed phenomenons such as the global heat flow and global lithospheric stress field in the Earth's surface caused by mantle convection, which is the primary mechanism for the transport of heat from the Earth's deep interior to its surface and the underlying force mechanism of dynamics in the Earth.Chapter 1 reviews the historical background and present research state of mantle convection theory.In Chapter 2, the basic conception of thermal convection and the basic theory about mantle flow.The effects on generation and distribution of global lithospheric stres s field induced by mantle flow are the subject of Chapter 3. Mantle convection causes normal stress and tangential stresses at the bottom of the lithosphere, and then the sublithospheric stress field induces the lithospheric deformation as sixrface force and results in the stress field within the lithosphere. The simulation shows that the agreement between predictions and observations is good in most regions. Most of subduction zones and continental collisions are under compressive. While ocean ridges, such as the east Pacific ridge, the Atlantic ridge and the east African rift valley, are under tensile. And most of the hotspots preferentially occur in regions where calculated stress is tensile. The calculated directions of the most compressive principal horizontal stress are largely in accord with that of the observation except for some regions such as the NW-Pacifie subduction zone and Qinghai-Tibet Plateau, in which the directions of the most compressive principal horizontal stress are different. It shows that the mantel flow plays an important role in causing or affecting the large-scale stress field within the lithosphere.The global heat flow simulation based on a kinematic model of mantle convection is given in Chapter 4. Mantle convection velocities are calculated based on the internal loading theory at first, the velocity field is used as the input to solve the thermal problem. Results show that calculated depth derivatives of the near surface temperature are closely correlated to the observed surface heat flow pattern. Higher heat flow values around midocean ridge systems can be reproduced very well. The predicted average temperature as a function of function of depth reveals that there are two thermal boundary layers, one is close to the surface and another is close to the core-mantle boundary, the rest of the mantle is nearly isothermal. Although, in most of the mantle, advection dominates the heat transfer, the conductive heat transfer is still locally important in the boundary layers and plays an important role for the surface heat flow pattern. The existence of surface plates is responsible for the long wavelength surface heat flow pattern.In Chapter 5, the effects on present-day crustal movement in the China Mainland resulted from the mantle convection are introduced. Using a dynamic method, we present a quantitative model for the present-day crustal movement in China. We consider not only the effect of the India-Eurasia collision, the gravitational potential energy difference of the Tibet Plateau, but also the contribution of the shear traction on the bottom of the lithosphere induced by the global mantle convection. The comparison between our results and the velocity field obtained from the GPS observation shows that our model satisfactorily reproduces the general picture of crustal deformation in China. Numerical modeling results reveal that the stress field on the base of the lithosphere induced by the mantle flow is probably a considerable factor that causes the movement and deformation of the lithosphere in continental China with its eflfcet focuing on the Eastern China A numerical research on the small-scale convection with variable viscosity in the upper mantle is introduced in Chapter 6. Based on a two-dimensional model, small-scale convection in the mantle-lithosphere system with variable viscosity is researched by using of finite element method. Variation of viscosity in exponential form with temperature is considered in this paper The results show that if viscosity is strongly temperature-dependent, the upper part of the system does not take a share in the convection and a stagnant lid, which is identified as lithosphere, is formed on the top of system because of low temperature and high viscosity. The calculated surface heat flow, topography and gravity anomaly are associated well with the convection pattern, namely, the regions with high heat flow and uplift correspond to the upwelling flow, and vice versa.In Chapter 7, we give a brief of future research subject: The inversion of lateral density heterogeneity in the mantle by minimizing the viscous dissipation.