螺旋藻多糖对肿瘤细胞生长及Hela细胞早期凋亡作用的实验研究

采用MTT法(四甲基偶氮唑盐比色法)研究了钝顶螺旋藻多糖(PSP)对Hela细胞及HepG2细胞生长的抑制作用。结果表明,随PSP浓度及培养时间的增加,肿瘤细胞存活率逐渐降低,抑制率逐渐增加,以PSP40 mg/L作用72 h最为显著。应用Annexin V/PI双染色流式细胞仪检测了早期Hela细胞凋亡,未经PSP处理的正常Hela细胞凋亡细胞极少,经PSP处理的细胞,凋亡细胞的百分比明显高于正常对照组,其作用随着剂量的增加和时间的延长而增强,具有量效关系和时效关系。结果说明PSP的抗肿瘤机制,除了诱导肿瘤细胞凋亡,还存在细胞毒性等其他机制,是多种机制共同作用的结果。     

Mitigation of Ice-Induced Vibrations for Offshore Platforms Using Tuned Mass Damper

The problems of ice-induced vibration have been noticed and concerned since the 1960s, but it has not been well resolved. One reason is that the dynamic interaction between ice and structure is so complicated that practical ice force model has not been developed. The recent full-scale tests conducted on jacket platforms in the Bohai Sea presented that ice could cause intense vibrations which endanger the facilities on the deck and make discomfort for the crew. In this paper, the strategy of mitigation of ice-induced offshore structure vibration is discussed. Based on field observations and understanding of the interaction between ice and structure, the absorption mitigation method to suppress ice-induced vibration is presented. The numerical simulations were conducted for a simplified model of platform attached with a Tuned Mass Danlper （TMD） under ice force function and ice force time history. The simulation results show that TMD can fa- vorably reduce ice-induced vibrations, therefore, it can be considered to be an alternative approach to utilize. Finally, the application possibilities of utilizing TMDs on other miniature offshore structures in ice-covered areas of marginal oil fields are discussed.     

Stable isotope ratios in Cape gannets around the southern coasts of Africa reveal penetration of biogeographic patterns in oceanic signatures

The southern coasts of Africa are influenced by two major oceanic currents, leading to biogeographic patterns in inshore and offshore species assemblages, and in the stable isotope signatures of suspended particulate matter and filter-feeding mussels. We used the stable isotope ratios of carbon (¹³C/¹²C) and nitrogen (¹⁵N/¹⁴N) from the blood and feathers of adult and chick Cape gannets (Morus capensis) to investigate whether the geographic differences observed at the lower levels in the marine communities are deep penetrating effects that reach top predators. Additionally, we evaluated whether trophic segregation occurs between adult and reared chick gannets, and whether a shift to wintering habitat occurs in adults. The study was conducted during the 2006 breeding season on Bird Island in the Agulhas system, and on Malgas and Ichaboe Islands, in the south and north Benguela respectively. Our results showed significant differences in the isotope ratios of members of different colonies, but no intra-colony differences between tissues or age groups. These results indicate that there is neither age-related nor temporal segregation in the diet of members of the same colony. Feather isotopic values suggest that adults remain all year round in the same habitats, and do not undertake long migration after reproduction. Since all gannets tend to target similar prey, we attributed among-colony differences in isotope signatures mostly to the oceanic conditions experienced by the main prey of birds rather than substantial differences in diet composition. Overall, isotopic signatures segregate the two current systems, with depleted carbon values in the Agulhas and enriched nitrogen values in the upwelled waters of the Benguela. Within the Benguela birds from Ichaboe in the north had higher δ¹⁵N values than those from Malgas in the south, which we attributed to differences in the functioning of the upwelling cells in the vicinity of the two colonies. Finally, slight variation in the proportion of main prey and discards from fisheries may contribute to the variation in the stable-isotope signatures between colonies in the Benguela.     

贻贝(Mytilus edulis)的核型与减数分裂

利用体内注射ＰＨＡ和秋水仙素的方法，以锶和生殖腺为材料，对贻贝ＭｙｔｉｌｕｓｅｄｕｌｉｓＬｉｎｎａｅｕｓ的核型和减数分裂进行了观察分析，结果为，二倍体数２ｎ＝２８，核型为１０ｍ＋１２ｓｍ＋６ｓｔ，ＮＦ＝５０。没有发现异形性染色体，贻贝的减数分裂与其他动物类似，也没有发现异形染色体的特殊行为。     

东海二甲基硫丙酸的分布及其制约因素的初步研究

于１９９４年４月对海水域二甲基硫丙酸浓度进行观测,结合对叶绿素和营养盐的监测结果,分析研究了了ＤＭＳＰ分布及其调控因素。结果表明,ＤＭＳＰ浓度范围为０．１７－５．６６ｎｍｏｌ／Ｌ,最高浓度出现一４１０站。     

蛋白核小球藻在废水污泥中培养的研究

啤酒厂废水污泥中含有一定的营养元素和活性物质。本研究利用废水污泥培养蛋白核小球藻（Chlorellapyrenoidosa）取得了初步结果。将一定比例的活性污泥掺入普通培养液形成混合培养基,其中80：20试验组无论从蛋白核小球藻的生物量还是粗蛋白的含量均与普通培养基的培养产物近似,具有实践意义。结果表明,混合培养基培养某些藻类,不仅降低了养殖成本,还可净化环境,为废水污泥用于藻类养殖开辟了一条新途径。     

中华鲟随机扩增多态性DNA及遗传多样性研究

采用随机扩增多态性ＤＮＡ（ＲＡＰＤ）技术进行了连续３年（１９９５－１９９７）共７０尾来源于长江水系中华鲟样本遗传分析,共用了４０个１０ｂｐ长的随机引物,在２６种可供分析的引物中,只有ＯＰＫ０１、ＯＰＫ０２、ＯＰＫ０３、ＯＰＫ０９、ＯＰＫ１４和ＯＰＱ０８ＲＡＰＤ－ＰＣＲ产物有多态现象,多态引物占２３％。２６个引物中共扩增出１０８条稳定的ＤＮＡ带。其中１２条带为多态带,多态座位比例为１１．１％。个体间     

扇贝多肽在体外对免疫细胞活性的影响及其抗紫外线的氧化损伤作用

采用噻唑盐（MTT）比色方法研究在紫外线辐射损伤条件下扇贝多肽对免疫细胞的保护作用，并探讨扇贝多肽对胸腺细胞和脾细胞活性的影响，结果表明，扇贝多肽具有抗紫外线氧化损伤的作用，可减轻或抑制紫外线对胸腺细胞和脾细胞的氧化损伤，并且呈剂量依赖性，扇贝多肽在0.5%-10.0%的浓度范围内，其抗氧化能力随浓度的增高而增强，在正常条件下可显著增强免疫细胞的活性，并且可拮抗雌激素对免疫细胞的抑制作用。提示扇贝多肽不仅具有抗氧化损伤作用，而且具有免疫增强使用。     

Biogeochemical Variation in Dimethylsulfide, Phytoplankton Pigments and Heterotrophic Bacterial Production in the Subarctic North Pacific during Summer

Dimethylsulfide (DMS), chlorophyll a (Chl-a), accessory pigments (fucoxanthin, peridinin and 19-hexanoyloxyfucoxanthin), and bacterial production (BP) were measured in the surface layer (0–100 m) of the subarctic North Pacific, including the Bering Sea, during summer (14 July–5 September, 1997). In surface sewater, the concentrations of DMS and Chl-a varied widely from 1.3 to 13.2 nM (5.1 ± 3.0 nM, mean ± S.D., n = 48) and from 0.1 to 2.4 µg L^–1 (0.6 ± 0.6 µg L^–1, n = 24), respectively. In the subarctic North Pacific, DMS to Chl-a ratios (DMS/Chl-a) were higher on the eastern side than the western side (p < 0.0001). Below the euphotic zone, DMS/Chl-a ratios were law and the correlation between DMS and Chl-a was relatively strong (r ² = 0.700, n = 27, p < 0.0001). In the euphotic zone, DMS/Chl-a ratios were higher and the correlation between DMS and Chl-a was weak (r ² = 0.128, n = 50, p = 0.01). The wide variation in DMS/Chl-a ratios would be at least partially explained by the geographic variation in the taxonomic composition of phytoplankton, because of the negative correlation between DMS/Chl-a and fucoxanthin-to-Chl-a ratios (Fuc/Chl-a) (r ² = 0.476, n = 26, p = 0.0001). Furthermore, there was a positive correlation between DMS and BP (r ² = 0.380, n = 19, p = 0.005). This suggests that BP did not represent DMS and dimethylsulfoniopropionate (DMSP) removal by bacterial consumption but rather DMSP degradation to DMS by bacterial enzyme.     

黄河河流水体二氧化碳分压及其影响因素分析

根据2003年秋季黄河河流水体二氧化碳分压(p(CO2))的实测数据，结合水文、化学和生物等要素的同步观测资料，对河流水体p(CO2)的影响因素进行了探讨。研究结果表明：生物好氧呼吸作用不是影响河流水体p(CO2)的主要因素，黄河河流p(CO2)的高低主要受水体碳酸盐系统的控制。