Uptake,Depuration and Subcellular Distribution of Cadmium in Various Tissues of Perna viridis

Green-lipped mussels (Perna viridis) were collected from a local mariculture site and placed in pre-cleaned sea water tanks containing 0, 0.2, 0.5 and 1.3 μg/ml CdCl2. The level of Cd in the gill, viscera and gonad was measured. The concentration of Cd in the 3 tissues increased linearly over 4 days' of exposure. The rate of uptake depends on the concentration of Cd in the water. In the 3 tissues studied, the maximum rate of uptake (Vmax) was highest in the gill (500μg/g dry weight/day), followed by viscera (100μg/g dry weight/day) and gonad (56.8 μg/g dry weight/day). The majority of the Cd taken up was bound to a fraction of the heat-stable proteins similar to metallothioneins. The rate of Cd depuration from the tissues was poor. There was no change in Cd concentration over 8 days' depuration in clean water

Depuration of paralytic shellfish toxins in Japanese scallop(Patinopecten yessoensis) in natural environment

To study the paralytic shellfish toxins（PSTs） depuration in Japanese scallop Patinopecten yessoensis in natural environment, Japanese scallops naturally contaminated with paralytic shellfish poisoning（PSP） toxins in the Dayao Bay in the northern Huanghai Sea are transited to Qipanmo waters in the Bohai Sea of no reported PSTs incidents. The levels and profile of PSTs during 30-day depuration are detected by the high performance liquid chromatography with fluorescence detection（HPLC-FLD）. The results show that the toxicity of the PSTs in soft tissues decreases to a relatively low level at Day 9. Moreover, the depurated ratio at the early stage of the PSTs depuration is higher than that at the later stage. The toxicity analysis of dissected organs reveals that the digestive gland is the most contaminated PSTs part, which is of important implication for the human health and scallop aquiculture. The mortality of Japanese scallops during PSTs depuration experiment is relevant to PSTs level in the soft tissue.

Modeling the depuration rates of polychlorinated biphenyls in two mussel species with theoretical molecular descriptors

Using theoretical molecular descriptors as well as partial least squares(PLS) regression,two quantitative structure-activity relationship(QSAR) models were developed for depuration rate constants(kd) of polychlorinated biphenyls(PCBs) in two species of mussels,Perna viridis and Dreissena polymorpha.The cross-validated Q2cum(an indicator of fitting of goodness) values for the two models are 0.501 and 0.756,and the standard deviation(SD) is 0.084 and 0.076,respectively.The achievement of satisfactory Q2cum and low SD values indicates good predictive ability and precision of the two models.The significant descriptors governing lgkd include polarizability(α),molecular volume(MV),molecular weight(Mw),molecular surface area(S),and total energy(TE).The key descriptors in the models reflect that van der Waals interactions play a dominant role in the depuration of PCBs.The depuration of PCBs in the two mussel species may be mainly attributed to the biota-water phase partitioning processes.

基于Tri-Training和数据剪辑的半监督聚类算法

提出一种半监督聚类算法,该算法在用seeds集初始化聚类中心前,利用半监督分类方法Tri-training的迭代训练过程对无标记数据进行标记,并加入seeds集以扩大规模;同时,在Tri-training训练过程中结合基于最近邻规则的Depuration数据剪辑技术对seeds集扩大过程中产生的误标记噪声数据进行修正、净化,以提高seeds集质量.实验结果表明,所提出的基于Tri-training和数据剪辑的DE-Tri-training半监督聚类新算法能够有效改善seeds集对聚类中心的初始化效果,提高聚类性能.

Gastrointestinal toxicity induced by microcystins

Microcystins(MCs) are produced by certain bloomforming cyanobacteria that can induce toxicity in various organs, including renal toxicity, reproductive toxicity, cardiotoxicity, and immunosuppressive effects. It has been a significant global environmental issue due to its harm to the aquatic environment and human health. Numerous investigators have demonstrated that MC exposure can induce a widespread epidemic of enterogastritis with symptoms similar to food poisoning in areas close to lakes. Both in vivo and in vitro studies have provided evidence of positive associations between MC exposure and gastrointestinal toxicity. The toxicity of MCs on the gastrointestinal tract is multidimensional. MCs can affect gastrointestinal barrier function and shift the structure of gut microbiota in different gut regions. Furthermore, MCs can inhibit the secretion of gastrointestinal digestive enzymes and the release of inflammatory cytokines, which affects the expression of immune-related genes in the intestine. The damage of the intestine is closely correlated to MC exposure because the intestine is the main site for the digestion and absorption of nutrients. The damage to the gastrointestinal tract due to MCs was summarized from different aspects, which can be used as a foundation for further exploration of molecular damage mechanisms.