Simple determination of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) using solid-phase microextraction and gas chromatography-mass spectrometry

Solid-phase microextraction (SPME) is a simple, sensitive and less destructive method for the determination of dimethylsulfide (DMS) in seawater. Combined with detection by gas chromatography-mass spectrometry (GC-MS), the method had sufficient sensitivity (minimum detectable concentration of DMS was 0.05 nM), and practical levels of reproducibility (relative standard deviation ≤7%) and linearity (r ² > 0.995) over a wide concentration range (0.5 to 910 nM). The protocol developed was applied to a Sagami Bay water sample to determine concentrations of DMS and DMSP, and in situ DMSP-lyase activity.     

南极中山站大气气溶胶的化学组成及其来源的判别

从1998年3月7日至1999年11月23日历时21个月，在南极中山站连续采集89个海洋气溶胶样品，本文提供全部样品的13种化学元素Cu、Pb、Zn、Cd、Fe、Al、Mn、Cr、V、K、Na、Ca、Mg含量的实测值．研究表明中山站气溶胶化学成份的含量具有季节性变化的特征．通过相关分析、因子分析、富集因子等方法判别不同时间段中山站气溶胶化学成份的来源。     

钝顶螺旋藻藻蓝蛋白和多糖的抗肿瘤免疫活性研究

对钝顶螺旋藻藻蓝蛋白 (PC)和多糖 (PSP)的抗肿瘤免疫活性进行了研究。采用免疫酶标技术、MTT法及定量溶血分光光度测定法等免疫分析实验 ,从免疫器官、免疫细胞、免疫分子 3个水平上进行藻蓝蛋白和多糖的抗肿瘤免疫活性检测。结果显示 ,藻蓝蛋白和多糖处理组小鼠瘤块直径及瘤体重量均小于对照组 ,T细胞及 B细胞活性明显增强 ,体液抗体量显著提高 ,螺旋藻藻蓝蛋白比多糖抑制肿瘤细胞生长和提高机体免疫力的作用更明显。     

南海西南部晚更新世以来元素地球化学特征的古环境意义

对南海西南部近湄公河三角洲中陆坡上的MD01-2392站样品进行的地球化学分析表明,该站的沉积物主要为湄公河带来的陆源碎屑,并且其物源四十万年来没有发生明显变化。分别用元素TiO2、CaO估算出沉积物中陆源碎屑的含量及CaCO3的含量,结果显示CaCO3在间冰期时高,而在冰期时低,表现出“大西洋旋回”的特征。陆源碎屑含量与CaCO3含量相反,显示出南海CaCO3旋回属于稀释旋回。元素的Ti标准化值表明,该站沉积物源区在冰期时化学风化弱,而在间冰期时相对较强,说明间冰期时物源区存在相对温暖湿润的气候环境。     

Risk assessment of TBT in the Japanese short-neck clam (Ruditapes philippinarum) of Tokyo Bay using a chemical fate model

A risk assessment of Tributyltin (TBT) in Tokyo Bay was conducted using the Margin of Exposure (MOE) method at the species level using the Japanese short-neck clam, Ruditapes philippinarum. The assessment endpoint was defined to protect R. philippinarum in Tokyo Bay from TBT (growth effects). A No Observed Effect Concentration (NOEC) for this species with respect to growth reduction induced by TBT was estimated from experimental results published in the scientific literature. Sources of TBT in this study were assumed to be commercial vessels in harbors and navigation routes. Concentrations of TBT in Tokyo Bay were estimated using a three-dimensional hydrodynamic model, an ecosystem model and a chemical fate model. MOEs for this species were estimated for the years 1990, 2000, and 2007. Estimated MOEs for R. philippinarum for 1990, 2000, and 2007 were approximately 1–3, 10, and 100, respectively, indicating a declining temporal trend in the probability of adverse growth effects.A simplified software package called RAMTB was developed by incorporating the chemical fate model and the databases of seasonal flow fields and distributions of organic substances (phytoplankton and detritus) in Tokyo Bay, simulated by the hydrodynamic and ecological model, respectively.     

乙醇对文昌鱼酸性磷酸酶活力与构象的影响

文昌鱼酸性磷酸酶是一种含有铁离子的金属酶，酶的紫外－可见光谱扫描，２８０ｎｍ，５００ｎｍ有最大吸收峰，３２０ｎｍ有肩峰。荧光扫描：在２８１ｎｍ激发下，３３０ｎｍ有发射峰，在４８０ｎｍ激发下，５１５ｎｍ有一发射峰。     

Locomotor activity rhythm in the Japanese eel Anguilla japonica elvers

Under artificial LD cycles(6,12,18 L),the elvers of Japanese eel,Anguilla japonica,showed a 24 h cycle of locomotor activity rhythm being most active at light transitions:the eels' activity rose to a primary peak after lights-off,followed by a quiescent period during which they buried into the shelters or lying motionlessly on sand for most of the time,and then reached a secondary peak before lights-on.Elvers could resynchronize their activity rhythm with a new photo cycle within 4 d.Moreover,their activity level at dark phase significantly increased as the light period was prolonged:higher activity levels during shorter dark period.However,the elvers did not display clearly the existence of a circadian rhythm under constant light or dark conditions.The timing of daily activity rhythm evidenced in the Japanese eels may occur through the action of the LD cycles with a weak participation of an endogenous circadian system.In all the LD cycles,over 99% of the activity occurred in the dark phase,indicating that the eels were always nocturnally active no matter what time of day it might be.Under 12 L conditions,the eels' activity level and the time outside sand were significantly elevated both at light and dark phases as temperature increased from 10~15 to 20~25 ℃.The activity rhythm pattern(i.e.,two peaks occurring around light transitions) did not apparently change among temperatures.However,in contrast with the primary activity peaks immediately after lights-off at 20 and 25 ℃,the timing of the primary peaks at 10 and 15 ℃ showed a latency of a few hours following lights-off,indicating the inhibiting effect of low temperature on the eels' activity.     

An overview of the Oyashio ecosystem

The Oyashio shelf region and the seasonally ice-covered areas north of Hokkaido are highly productive, supporting a wide range of species including marine mammals, seabirds and commercially important species in the western subarctic Pacific. The fishes include gadids, such as walleye pollock and Pacific cod, and subarctic migratory pelagic fishes such as chum salmon and pink salmon. It is also an important summer feeding ground for subtropical migrants such as the Japanese sardine, Japanese anchovy, Pacific saury, mackerels, Japanese common squid, whales and seabirds. In recent decades, some components of the Oyashio ecosystem (i.e., phytoplankton, mesozooplankton, gadid fish, and subtropical migrants) have shown changes in species abundance or distribution that are correlated with environmental changes such as the 1976/1977 and 1988/1989 regime shifts. The First Oyashio Intrusion moved northward from the mid-1960s until the late 1970s, when it moved southward until the 1980s, after which it returned to the north again after the mid-1990s. The sea-surface temperature in spring decreased after the late 1970s, increased after the late 1980s, and remained high during the 1990s. The extent of ice cover in the Sea of Okhostk also decreased during the latest warming in the 1980–1990s but has increased again since the late 1990s. This and other variabilities affect the Oyashio ecosystem and the surrounding region.     

珠江口水域化学耗氧量、溶解氧、无机磷与有机磷的三维水质数学模拟

珠江沿岸城市排污量大,对污染源治理能力十分有限,大量污染物通过河流或直接排放到珠江口,河口区半封闭的地形及潮水顶托使得污染物不易输送出外海,致使珠江口水质恶化,原有海洋生态环境遭到破坏,反过来制约了经济的发展.