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71.
张莉 《海洋与湖沼》2007,38(1):62-68
采用凝胶过滤层析、SDS-PAGE电泳、Bradford法和苯酚-硫酸法等生物化学方法对菲律宾蛤仔中的蛋白聚糖(PG1和PG2)进行分离纯化,研究其理化性质。采用MTT方法研究蛋白聚糖对人肝癌细胞SMMC-7721和人正常肝细胞HL-7702生长的影响。通过小鼠体内实验研究蛋白聚糖的抗肿瘤活性和对荷瘤小鼠免疫功能的影响。结果表明,PG1分子量大约为20kDa,多糖含量为70.09%,蛋白质含量为15.4%。PG2的多糖含量为82.53%,蛋白质含量为7.26%。PG1在200μg/ml浓度时对SMMC-7721的生长抑制率为73.30%,随浓度的升高,抑制率并未发生明显改变。PG2对SMMC-7721的生长抑制作用呈剂量依赖性,在500μg/ml的浓度下,其抑制效果与PG1的抑制效果相当。在同样浓度下,PG1对人正常肝细胞的生长和功能没有明显影响。PG1呈剂量-效应关系明显增加荷瘤小鼠脾指数,促进荷瘤小鼠脾淋巴细胞转化,且没有降低体重及其他毒副作用。PG1对小鼠S180肉瘤的抑制作用可能是通过直接杀伤肿瘤细胞的细胞毒作用和提高小鼠细胞免疫水平来实现。  相似文献   
72.
The characteristics of the ratios between cadmium (Cd) and phosphorus (P) in settling particles collected from the Okinawa Trough in the East China Sea were examined using a sediment trap, moored at a depth of 811 m for one year. The Cd/P ratios varied within a narrow range throughout the year, in spite of the large seasonal change in the total dry mass, Cd, and P fluxes. The average Cd/P ratio of settling particles was 0.062 (nmol/μmol), which was obviously lower than that of surface seawater around the study site (0.16). This lower ratio in the Okinawa Trough particles collected using the 811 m-moored trap certainly reflected the mixture of biologically produced organic matter around the study site and other components that were mainly transported as lateral flux from the shelf edge and slope area of the East China Sea.  相似文献   
73.
Japanese fisheries production in the Japan/East Sea between 1958 and 2003 increased to their peak (1.76 million tons) in the late 1980s and decreased abruptly with the collapse of Japanese sardine. Catch results for 58 fisheries and various environmental time-series data sets and community indices, including mean trophic level (MTL) and Simpson’s diversity index (DI), were used to investigate the impacts of fishing and climate changes on the structure of the fish community in the Tsushima warm current (TWC) region of the Japan/East Sea. The long-term trend in fisheries production was largely dependent on the Japanese sardine that, as a single species, contributed up to 60% of the total production in the Japanese waters of the Japan/East Sea during the late 1980s. Excluding Japanese sardine, production of the small pelagic species was higher during 1960s and 1990s but lower during 1970s and 1980s. This variation pattern generally corresponds with the trend in water temperature, warmer before early 1960s and after 1990s but colder during 1970s and 1980s. The warm-water, large predatory fishes and cold water demersal species show opposite responses to the water temperature in the TWC region, indicating the significant impact of oceanic conditions on fisheries production of the Japan/East Sea. Declines in demersal fishes and invertebrates during 1970s and 1980s suggested some impact of fishing. MTL and DI show a similar variation pattern: higher during 1960s and 1990s but lower during 1970s and 1980s. In particular, the sharp decline during the 1980s resulted from the abundant sardine catches, suggesting that dominant species have a large effect on the structure of the fish community in the Japan/East Sea. Principal component analysis for 58 time-series data sets of fisheries catches suggested that the fish community varied on inter-annual to inter-decadal scales; the abrupt changes that occurred in the mid-1970s and late 1980s seemed to correspond closely with the climatic regime shifts in the North Pacific. These results strongly suggest that the structure of the fish community in the Japan/East Sea was largely affected by climatic and oceanic regime shifts rather than by fishing. There is no evidence showing “fishing down food webs” in the Japan/East Sea. However, in addition to the impacts of abrupt shifts that occurred in the late 1980s, the large predatory and demersal fishes seem to be facing stronger fishing pressure with the collapse of the Japanese sardine.  相似文献   
74.
海浪日最大波高序列的一种标度性质   总被引:1,自引:0,他引:1  
应用重标度分析方法研究小麦岛海洋观测站1961-1980年二十年海浪日最大波高序列时发现,该序列并不是相互独立的,而是具有记忆性和持久性,详细的论证表明分式布朗运动模型是描述海浪日最大波高序列的一个较好的模型,同时,应用分式布朗运动模型我们找到了存在于海浪日最大波高序列中的一种标度性质-累积离差(t)的统计自仿射性。  相似文献   
75.
76.
Yeli Yuan  C.C. Tung   《Ocean Engineering》1984,11(6):593-607
This paper discusses the use of Hermite polynomial in the derivation of statistical properties of waves, wave field kinematics and dynamics and wave forces under various conditions. Specifically, covariance functions and approximate spectra are obtained for (1) wave force on vertical cylinder according to Morison's formula, (2) horizontal fluid particle velocity considering the effects of free surface fluctuations, and (3) elevation of breaking waves.  相似文献   
77.
The production and distribution of biological material in wind-driven coastal upwelling systems are of global importance, yet they remain poorly understood. Production is frequently presumed to be proportional to upwelling rate, yet high winds can lead to advective losses from continental shelves, where many species at higher trophic levels reside. An idealized mixed-layer conveyor (MLC) model of biological production from constant upwelling winds demonstrated previously that the amount of new production available to shelf species increased with upwelling at low winds, but declined at high winds [Botsford, L.W., Lawrence, C.A., Dever, E.P., Hastings, A., Largier, J., 2003. Wind strength and biological productivity in upwelling systems: an idealized study. Fisheries Oceanography 12, 245–259]. Here we analyze the response of this model to time-varying winds for parameter values and observed winds from the Wind Events and Shelf Transport (WEST) study region. We compare this response to the conventional view that the results of upwelling are proportional to upwelled volume. Most new production per volume upwelled available to shelf species occurs following rapid increases in shelf transit time due to decreases in wind (i.e. relaxations). However, on synoptic, event time-scales shelf production is positively correlated with upwelling rate. This is primarily due to the effect of synchronous periods of low values in these time series, paradoxically due to wind relaxations. On inter-annual time-scales, computing model production from wind forcing from 20 previous years shows that these synchronous periods of low values have little effect on correlations between upwelling and production. Comparison of model production from 20 years of wind data over a range of shelf widths shows that upwelling rate will predict biological production well only in locations where cross-shelf transit times are greater than the time required for phytoplankton or zooplankton production. For stronger mean winds (narrower shelves), annual production falls below the peak of constant wind prediction [Botsford et al., 2003. Wind strength and biological productivity in upwelling systems: an idealized study. Fisheries Oceanography 12, 245–259], then as winds increase further (shelves become narrower) production does not decline as steeply as the constant wind prediction.  相似文献   
78.
Abundance and distribution of phytoplankton in seawater at southwestern East/Japan Sea near Gampo were investigated by HPLC analysis of photosynthetic pigments during summer of 1999. Detected photosynthetic pigments were chlorophyll a, b, c1+2 (Chl a, Chl b, Chl c1+2), fucoxanthin (Fuco), prasinoxanthin (Pras), zeaxanthin (Zea), 19’-butanoyloxyfucoxanthin (But-fuco) and beta-carotene (β-Car). Major carotenoid was fucoxanthin (bacillariophyte) and minor carotenoids were Pras (prasinophyte), Zea (cyanophyte) and But-fuco (chrysophyte). Chl a concentrations were in the range of 0.16-8.3/land subsurface chlorophyll maxima were observed at 0-10m at inshore and 30–50 m at offshore. Thermocline and nutricline tilted to the offshore direction showed a mild upwelling condition. Results from size-fraction showed that contribution from nano+picoplankton at Chl a maximum layer was increased from 18% at inshore to 69% at offshore on average. The maximum contribution from nano+picoplankton was found as 87% at St. E4. It was noteworthy that contribution from nano+picoplanktonic crysophytes and green algae to total biomass of phytoplankton was significant at offshore. Satellite images of sea surface temperature indicated that an extensive area of the East/Japan Sea showed lower temperature (<18 °C) but the enhanced Chl a patch was confined to a narrow coastal region in summer, 1999. Exceptionally high flux of low saline water from the Korea/Tsushima Strait seemed to make upwelling weak in summer of 1999 in the study area. Results of comparisons among Chl a from SeaWIFs, HPLC and fluorometric analysis showed that presence of Chl b cause underestimation of Chl a about 30% by fluorometric analysis but overestimation by satellite data about 30-75% compared to HPLC data.  相似文献   
79.
Mesoscale features in the eastward extension of the Kuroshio were investigated using assimilation of TOPEX/POSEIDON (T/P) data into a three-layer quasi-geostrophic model. The T/P data exhibited an elongated state of the southern recirculation gyre in 1993–95 and 1997, between whose two periods the gyre had a contracted state in 1995–96. A few stationary eddies were located in the southern gyre during the contracted state. The baroclinic instability, which was indicated by the phase shift from the uppermost-to the lowest-layer anomalies toward the downstream side, was evident near the Kuroshio Extension (KE) path. Since the instability never appeared in the artificial model without bottom topography, the topographic barrier for the eastward flow in the lowest layer was a necessary condition for the instability. The instability synchronized with the transition in the western region of the KE axis from the elongated to the contracted states. This evolution was interpreted as if the baroclinic instability played some part in the KE states and was a trigger for the transition from the elongated to the contracted states.  相似文献   
80.
用16S rRNA基因的内切酶图谱快速鉴别几种对虾病原菌   总被引:4,自引:0,他引:4  
坎普氏弧菌是青岛海洋大学生物系微生物实验室于1989-1990年自对虾养殖场中国对虾红腿病心脏及血淋巴中分离并鉴定的菌株,副溶血菌和溶藻胶弧菌两菌株于1994年9月得自中国科学院微生物研究所,为建立快速、准确的中国对虾病原菌的诊断技术,根据几种细菌的16SrRNA基因的序列,设计并合成该基因的多聚酶反应的引物PL1和PL2。并用该对引物分别从坎普氏弧菌、副溶血弧菌和溶藻胶弧菌的DNA要品中扩增出分  相似文献   
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