A review on the studies of acid-volatile sulfide in aquatic sediments

水体沉积物中酸可挥发性硫化物 (AVS)是总硫含量中活性最高的部分 ,是沉积物中有毒重金属的重要结合形态 ,它的含量在很大程度上影响着沉积物重金属的生物有效性 ,从而作为沉积物中有毒重金属环境污染评价的一个重要指标 ;就十多年来水体沉积物中酸可挥发性硫化物 (AVS)的研究进行了综述。概述了 AVS的测定方法及其影响因素 ;探讨了水体沉积物中 AVS含量时空变化的规律 ;同时就目前“同时可提取重金属”(SEM)与 AVS摩尔浓度比值和水体沉积物重金属生物毒性关系的研究进行了概括和分析。In this article, the latest development on the study of acid-volatile sulfide in aquatic sediment is reviewed. Acid-volatile sulfide (AVS) is operationally defined as sulfide in sediment which is soluble in cold acid, and was reported as the most active part of the total sulfur in aquatic sediments and a key partitioning phase controlling the activities of divalent cationic heavy metals in sediment. It has been reported that the measurement procedures of AVS concentration are very important for AVS study, the weight of sample taken for analysis, nitrogen flow rate, acid strength and digestion time could all affected the accuracy of AVS concentration analysis. Some other more convenient measure methods have been proposed, however, owing to different study conditions, there is no standard procedure to determine the concentration of AVS in aquatic sediment. The concentration of AVS in aquatic sediment is related to E _h (the redox potential) of the sediment, and has spatial and seasonal variations in sediment, therefore, it is very important which stratum of sediment should be selected to measure the AVS concentration and to used to predict the heavy metal pollution of the sediment. AVS had been proposed as the primary normalization phase for the development of sediment quality criteria for certain cationic metals because it could complex some cationic metals and thereby influences the toxicity of these metals to benthic organisms and has the potential to be an indicator of toxicity in both marine and freshwater sediments. Some studies indicated that the ratio of molar concentration between simultaneously extracted metals(SEM) and AVS can provide important insight into the potential bio-availability of toxic divalent heavy metal. Sediments with [SEM]/[AVS] ratios1.0 were thought to be toxic to benthic organisms. However, some other studies reported that the ratios>1.0 were not enough to indicate the sediment with heavy metals pollution, the other partitioning phases could also play an important role in reducing heavy metal toxicity. Furthermore, different benthic organisms may have different reactions under the same [SEM]/[AVS] ratio. The difference between the molar concentrations of SEM and AVS ([SEM]-[AVS]) should be used instead of [SEM]/[AVS] ratio as a measure of metals availability for it can provide important insight into the extent of additional available binding capacity, the magnitude by which AVS binding has been exceeded. More studies are therefore needed to understand the relations between the ratio of [SEM]/[AVS], heavy metal concentration in interstitial water, heavy metals distribution among different partitioning phases as well as different heavy metal interactions.国家自然科学基金资助项目 (3 0 170 190 )~

水体沉积物中酸可挥发性硫化物(AVS) 研究进展

水体沉积物中酸可挥发性硫化物(AV S) 是总硫含量中活性最高的部分, 是沉积物中有毒重金属的重要结合形态, 它的含 量在很大程度上影响着沉积物重金属的生物有效性, 从而作为沉积物中有毒重金属环境污染评价的一个重要指标; 就十多年来 水体沉积物中酸可挥发性硫化物(AV S) 的研究进行了综述。概述了AV S 的测定方法及其影响因素; 探讨了水体沉积物中AV S 含量时空变化的规律; 同时就目前“同时可提取重金属”(SEM ) 与AV S 摩尔浓度比值和水体沉积物重金属生物毒性关系的研 究进行了概括和分析

Rhizosphere Remediation of Phenanthrene-contaminated Sediment by Kandelia candel(L.) Druce

利用盆栽试验方法,研究了红树植物秋茄(kAndElIA CAndE(ll.) druCE)对多环芳烃菲污染沉积物的修复作用。结果表明,在5、10、20、40Mg·kg-1菲处理浓度下,菲对秋茄的生长具有抑制作用,沉积物中菲初始浓度越高抑制作用越明显。4个月的修复试验结果表明,与无植物对照相比,种植秋茄能够明显促进沉积物中菲的降解。根际沉积物中菲的去除率为69%--82%,而非根际沉积物中菲的去除率为59%--66.9%。相同污染水平处理下根际沉积物中菲残留浓度低于非根际沉积物,而菲降解菌数量、多酚氧化酶和脱氢酶活性高于非根际沉积物,从而提高了沉积物中菲的降解率。Rhizosphere-remediation of phenanthrene(PHE)-contaminated sediment with Kandelia candel(L.) Druce was investigated in soil-culture medium.The results showed that the growth of Kandelia candel was inhibited by PHE in a dose-dependent way at 5, 10, 20 or 40 mg·kg-1 of the studied PHE concentrations.On the other hand, Kandelia candel significantly promoted the degradation of PHE in sediment.After 4 months, 69%--82% and 59%--66.9% of the spiked PHE disappeared from the rhizospheric and the non-rhizospheric sediments, respectively.The residual concentration of PHE in the rhizosphere was lower than that in the non-rhizosphere at the same treatment concentration.Planting Kandelia candel enhanced the number of PHE-degrading bacteria and the activities of polyphenol oxidase and dehydrogenase, thus it improved the degradation rate of PHE.Taken together, our results suggested that planting Kandelia candel could strengthen the remediation of PHE-contaminated sediment.国家自然科学基金项目(30710206

环孢素A微乳巴布膏眼贴的制备及体外透皮实验

背景:免疫性眼病如甲亢性突眼、葡萄膜炎等疾病严重危害患者的眼健康,是眼科的常见病和疑难病,目前最常见的治疗方法为口服激素和免疫抑制剂,疗效不佳、反复发作、预后差同时全身不良反应很大。此类疾病多有淋巴细胞直接或间接参与。尝试把免疫抑制剂制作成巴布膏眼贴,通过局部外用使药物进入体内,利用环孢素A微乳的淋巴靶向性能,使环孢素A作用在睑周淋巴结,从而达到治疗或控制睑周淋巴结参与反应的免疫性眼病。这种方法为局部外用,不用全身用药,针对性强,药物剂量小,如果治疗效果好,可以有效治疗免疫性眼病并规避原有药物全身应用及长期应用的不良反应。目的:制备环孢素A微乳巴布膏眼贴,研究环孢素A微乳巴布膏眼贴体外透皮吸收特性。方法:将环孢素A微乳与聚丙烯酸钠、聚乙烯醇、聚乙烯吡络烷酮、明胶、桃胶、羧甲基纤维素钠、羟丙基纤维素等的水溶性高分子材料混合物以1 mg∶1 mL的比例充分混匀,涂布于无纺布上制备成巴布膏。Franz扩散池法测定该巴布膏在ICR小鼠腹部皮肤的通透性。高效液相色谱分析法检测环孢素A浓度,并进行皮肤刺激性和过敏性实验。结果与结论:实验成功制备了粘性适宜、透气透水性能良好、敷贴舒适、无皮肤刺激性和过敏反应的环孢素A微乳巴布膏,环孢素A含量为10 mg/片,质量浓度为1 g/L。环孢素A微乳透皮的浓度随着时间的增加而增加,具有较好的透皮效果。证实将环孢素A微乳制备成巴布膏眼贴是可行的。其在透皮性能、黏附能力、皮肤舒适方面表现良好。莆田学院校级课题(2014034);;莆田市科技局课题(2014S06(2))~

碳稳定同位素技术在植物水分胁迫研究中的应用

植物体的碳稳定同位素组成主要由植物本身的生物学特性决定, 但环境胁迫对其影响也十分明显。综述了碳稳定同位素 技术在研究植物水分利用效率、生物量高低及判断历史气候依据等研究领域的进展, 阐明了植物体的D13C 值对干旱、盐分及其 它环境因素的变化所引起的水分胁迫的响应, 并对碳稳定同位素对水分胁迫的响应机理进行了归纳和推断

盐胁迫下红海榄脯氨酸与活性氧代谢特征研究

系统地研究了盐胁迫下红海榄脯氨酸和活性氧的代谢特征. 结果表明:1) 脯氨酸含量随着盐度的增加出现先 降后升的趋势,当盐度达到10 时,其含量达最低. 在无盐和高盐环境下脯氨酸的大量积累是植物细胞的适应性反应, 其含量的高低不宜作为红海榄的抗盐性指标. 2) 超量脯氨酸积累会影响CO2 的固定,降低叶片细胞内有机物的合成 量,导致高盐胁迫下叶片的肉质化程度降低. 3) 红海榄SOD 活性随盐度呈先降低后升高的趋势,其超氧负离子释放 速率与SOD 活性呈负相关. 在中高盐度下,其POD、CAT 活性迅速增加,可有效地清除由SOD 与O H2 产生的H2O2 ,避免了由于盐胁迫导致活性氧增加而对质膜造成的伤害

铅胁迫对双孢蘑菇积累铅及抗氧化酶活性的影响

铅（Pb）是环境中最普遍的重金属污染物之一，不仅直接毒害土壤生物，破坏生态结构，还可以通过食物链迁移转化，危害人体健康，因此Pb污染的治理迫在眉睫。大型真菌具有强的金属富集能力及较高的相对年生物量，因此在对Pb污染的修复中有一定优势。本文以双孢蘑菇菌丝为研究对象，采用马铃薯葡萄糖琼脂培养的方法，研究不同浓度Pb胁迫对双孢蘑菇菌丝体的生长状况、形态以及机体内抗氧化酶系统的影响。结果表明，在实验浓度下Pb对双孢蘑菇菌丝体的生长率无显著性影响，且菌丝体中Pb含量随着培养基中Pb浓度的增加而升高，达到10.40 μg/g。扫描电镜和透射电镜结果显示，Pb胁迫下菌丝体的细胞结构受到一定破坏，细胞膜透性增加。X射线能谱分析观察得到细胞中的黑色颗粒为铅，表明Pb在细胞内的富集。菌丝体中丙二醛含量随Pb浓度的增加而增加，超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）等抗氧化酶活性随着Pb浓度的增加有不同程度的反应。在酶活力达到最大时，相比对照组分别增加了56.45%、61.36%、13.08%和10.59%，说明双孢蘑菇通过调节自身抗氧化酶系统适应Pb胁迫环境，据此在Pb污染的生物修复中具有应用潜力。福建省教育厅中青年教师教育科研项目（JAT170364）;;\n国家自然科学基金项目（31530008和318704832）资

木麻黄质膜离子泵在酸雨条件下对镧的响应

研究镧对酸雨(pH 为4. 5) 胁迫下木麻黄幼苗早期生长和质膜离子泵ATP 酶活性的影响。结果表明: 较低浓度La3 + 浸种能使幼苗株高、 根长、鲜重以及质膜质子泵活性明显增强, 在200 mg·L - 1 La3 + 处理时达到最高增强值, 而高浓度的La3 + 浸种使之表现出抑制效应; 幼苗质 膜钙泵的活性受La3 + 抑制。质子泵活性与细胞的伸长生长呈显著正相关关系, 镧对质子泵的活化作用有助于促进植物的生长, 且适量的镧具有缓解酸雨胁迫下生长的植物细胞质酸化, 维持细胞内环境稳定的间接作用。为抗酸雨和促生长, 木麻黄经镧浸种8 h 的最适宜La3 + 浓度为50～200 mg·L - 1

Effects of La~(3+) on ATPase Activities of Plasma Membrane Vesicles Isolated from Casuarina Equisetifolia Seedlings under Acid Rain Stress

The effects of La3 + on the growth and the ATPases activities of plasma membrane (PM) vesicles isolated from Casuarina equisetifolia seedlings under artificial acid rain (pH 4. 5) stress were studied. The results show that the height , length of roots , fresh weight and PM H+2ATPase activites of Casuarina equisetifolia seedlings increase by the treatments of soaking seeds in LaCl3 solutions with lower concentrations , and those can reach their peak values by treating with 200 mg ·L - 1 La3 + . However , in comparison with the CK, those are inhibited by the higher La3 + concentrations ; PM Ca2 +2AT2 Pase activity is inhibited with the treatments of La3 + . The results also reveal that the H+2ATPase activity and the growth of cell enlarge have a remarkable positive correlation , and La3 + activating H+2ATPase can facilitate plant growth. La3 + al2 so can alleviate cytosolic acidification of plant under acid rain stress and indirectly maintain the stability of intracellular environment . In order to resistant to acid rain and accelerate the growth of Casuarina equisetifolia , the suitable range of La3 + concentrations to soak seeds for 8 h is 50～200 mg·L - 1

Automated Software Testing Based on Constraint Processing

软件质量问题是工业界和学术界共同关注的热点问题. 软件测试是软件生产质量保障中的一项重要技术, 它的主要目的是尽可能地减少程序的错误. 本文着重研究了如何将约束求解应用到自动化软件测试. 这些研究大致可以分为如下三个方面. 本文第一方面的工作是关于白盒测试的研究. 白盒测试是面向程序代码的精确测试方法. 我们可以采用符号执行的方法来处理程序中的路径, 进而测试程序某些方面的性质. 然而, 由于符号执行的代价比较高, 测试程序的所有路径几乎不可能; 同时由于不可行路径的影响, 我们需要采用一些合适的测试准则或者路径选择策略来指导我们生成测试路径集合. 这一方面的工作包括两个部分.1) 本文提出了一种有效地产生可行基本路径的自动化方法, 能在可接受的时间内针对真实C 单元程序生成可行的基本路径. 这种方法产生的基本路径集合的带权路径长度的总和是最小的. 2) BPEL 是一种业务流程描述语言, 它可以表达程序复杂的并发行为. 本文提出了一种新颖的基于并发路径分析的BPEL 测试生成方法. 我们采用了一些限制组合的技术以及路径覆盖准则来避免测试路径的组合爆炸. 这个框架是模块化的, 所以很多测试中采用的技术, 比如不同的测 试准则和约束处理技术, 可以应用到其中. 本文第二方面的工作属于黑盒测试. 黑盒测试用于对程序的功能和接口进行测试. 我们可以用约束描述被测系统的规约或者测试准则, 在这种情况下, 黑盒测试用例的生成问题可以转化为有限约束满足问题. 这一部分的工作也包含两部分. 1) 提出了基于SAT 和回溯搜索算法的方法来解决组合测试生成问题. 并提出了一个新颖的剪枝策略SCEH, 用于提高算法的效率. 一些已有的启发式搜索策略, 以及一些对称打破技术, 也被应用到我们的回溯搜索算法中. 实验结果表明, 我们的方法在一些小规模实例上的表现优于其它的方法. 2) 对于针对布尔规范的MUMCUT 测试准则, 本文提出了一种基于SAT 的自动测试生成方法. 为了提高采用完备性SAT 工具时的求解效率, 我们采用了一些对称打破技术. 本文第三方面的工作是分析线性数值约束的逻辑关系. 在程序分析和验证中, 相同的约束可能会需要反复处理. 一种可能的加速方法就是预先找到约束之间的逻辑关系. 这种关系可以用规则来描述. 我们不大可能在多项式时间内找到所有的规则. 本文提出了一种基于搜索的算法, 以及一些启发式策略, 用于 寻找这些规则. 实验结果表明我们的方法能够在可接受的时间内产生足够的规则.The quality of software is a hot topic attracting attentions from both researchers and practitioners. Software testing is an important technique to guarantee the quality of software. It aims to reduce the software faults as much as possible. The author studied the problem of how to apply the constraint satisfaction techniques to software testing automatically. The study can be divided into the following three parts. The first part of this article is related to white-box testing. White-box testing is an accurate code-based software testing method. We can employ symbolic execution techniques to process the program paths, so as to test some features of programs. However, the complexity of symbolic execution technique makes it impossible to test all the paths of the program under test. Furthermore, some of the program paths may be infeasible. Therefore we need some test criteria and path selection strategies to guide the generation of the test paths. This part of work includes the following two aspects. 1) An efficient method is presented to generate a set of feasible basis paths. This method can generate feasible basis paths for real-world C unit programs automatically in acceptable time. The basis path set generated by this method has the minimum sum of weighted length. 2) BPEL is a business description language that could express complex concurrent behaviors. This paper presents a novel method of BPEL test case generation, which is based on concurrent path analysis. To avoid the combination explosion of the path number, some techniques and test criteria are used to restrict the combination. This method is modularized so that many test techniques, such as various test criteria and complex constraint solvers, can be applied. The second part of work is about black-box testing. Black-box Testing is used to test the functions and interfaces of programs. We can use constraints to describe the test criteria and the specifications of Software Under Test. Therefore the test generation for black-box testing can be translated into the finite domain constraint satisfaction problem. This part also includes two aspects. 1) A SAT-based approach and a backtracking search algorithm are presented to solve the problem. A novel pruning strategy called SCEH is proposed to increase the efficiency of the methods. Several existing search heuristics and symmetry breaking techniques are also used in the backtracking search algorithm. The experiments show that our method outperforms other methods in many small size cases. 2) This paper proposes a SAT-based method to generate the test cases automatically for MUMCUT testing of boolean specifications. To speed up the processing for the complete SAT tools, we make use of some symmetry breaking techniques. The last part of this paper studies the problem of finding Boolean relations among a set of linear numerical constraints. In program analysis and verification, there are some constraints that have to be processed repeatedly. A possible way to speed up the processing is to find some relations among these constraints first. The relations can be represented by rules. It is believed that we can not generate all the rules in polynomial time. A search based algorithm with some heuristics to speed up the search process is proposed. Experimental results with various examples show that our method can generate enough rules in acceptable time