龙须菜(Gracilariopsis lemaneiformis)海藻糖-6-磷酸合成酶(TPS)对逆境胁迫的响应

非还原性二糖海藻糖及其代谢物是调控植物生长发育和逆境响应的信号分子。本研究以大型海藻龙须菜(Gracilariopsis lemaneiformis)为对象,从基因转录、蛋白和酶活性3个水平探讨了海藻糖合成酶——海藻糖-6-磷酸合成酶(TPS)对高温、高盐及渗透胁迫的响应。龙须菜中4条TPS序列均具有TPS家族保守结构域(Glyco-transf-20)和TPP家族保守结构域(Trehalose-PPase),且属于Class I亚家族。在转录水平上,高盐胁迫主要促进了TPS1、TPS2和TPS4基因的表达,而渗透胁迫则总体抑制了TPS1、TPS2和TPS3基因的表达。在高盐胁迫48 h时, TPS1蛋白含量升高到对照组的2.03倍。在高温和高盐胁迫24 h时, TPS活性升高,而在高盐胁迫48 h及渗透胁迫条件下酶活性降低。可见海藻糖-6-磷酸合成酶参与了龙须菜抗高温和高盐胁迫的应答,但对渗透胁迫不敏感。该研究为提高龙须菜抗逆性及培育抗逆龙须菜品种提供了参考。     

全基因表达谱分析回神颗粒对app/ps1小鼠认知功能障碍的影响

目的：探讨回神颗粒对app/ps1双转基因小鼠脑组织全基因表达谱的影响。方法：对阿尔茨海默病模型小鼠应用回神颗粒,用小鼠全基因芯片分析脑组织基因表达谱,并进行通路分析。结果：全基因组芯片分析表明,共有300个基因同时在模型组和回神颗粒治疗组中发生变化。荧光信号比值大于2.0的基因有25个,其中下表达基因5个,上表达基因20个。该变化与细胞内信号传导通路、脂代谢、调控细胞凋亡、调控炎症反应等相关。结论：回神颗粒可以通过调节代谢、凋亡相关基因而有效改善阿尔茨海默病模型小鼠的痴呆程度,发挥抗痴呆的作用。     

一株大西洋深海酵母菌MAR-MC(3)的鉴定及生理特征分析

从大西洋中脊的深海底质中分离到一株酵母菌MAR-MC(3).该菌细胞为卵圆形,单端芽殖;在温度和NaCl浓度分别为35℃、3.4%条件下生长良好;能利用木糖、麦芽糖、半乳糖、蔗糖以及纤维二糖、阿拉伯糖、棉子糖、肌醇、木醇,但不能利用海藻糖;根据表型特征及rDNA序列分析鉴定为季也蒙毕赤酵母(Pichia guilliermondii).     

1987—2010年PN、TK断面黑潮流场的时空变化

基于1987-2010年PN断面和TK断面长期水文调查资料,使用逆方法计算了黑潮在这两个断面的流场,进而分析了其时空变化.结果表明,黑潮流量变化的主要周期为准4年和1年,季节变化呈夏强秋弱.两个断面流场的EOF分解的主模态表明:在PN断面,流场变化主要是同位相的,说明了黑潮流量的变化对流场起调控作用;而在TK断面,南北两个海沟中流场呈反位相变化,说明黑潮的路径变化是影响流场变化的主要因素.     

天然来源的α-葡萄糖苷酶抑制剂的研究进展

<正>α-葡萄糖苷酶(α-glucosidase,EC3.2.1.20)是一类能够催化碳水化合物非还原末端的α-1,4-糖苷键水解并释放出葡萄糖的酶,包括麦芽糖酶、异麦芽糖酶、蔗糖酶和海藻糖酶等。它在动物体内许多代谢途径中有重要意义,包括糖蛋白和糖脂的合成后加     

5-羟基川陈皮素对肿瘤细胞糖胺聚糖含量和结构的影响

糖胺聚糖(GAGs)位于细胞膜及胞外基质,它通过与多种生长因子受体结合来介导细胞内的信号转导,进而调控细胞的增殖与分化。研究表明,GAGs结构或含量变化在肿瘤发生和发展中发挥了重要作用。黄酮类化合物可影响肿瘤细胞表面GAGs合成,前期研究发现,5-羟基川陈皮素(5HPMF)可通过干预细胞内多种信号通路进而抑制肺癌和结肠癌细胞增殖,然而,5HPMF如何影响GAGs结构和含量的变化进而介导信号转导通路的机制还不清楚。基于此,本研究利用BaF3细胞模型,流式细胞仪及HPLC技术,首次探讨了5HPMF对肺癌和结肠癌细胞GAGs含量和结构的影响。结果表明,来源于HT29和A549细胞的GAGs可增强FGF1介导的BaF3细胞生长而5HPMF(10μmol·L-1)则显著地抑制其生长作用,且5HPMF可显著地降低HCT116和A549细胞表面FGF2或FGF8介导的GAGs·FGF·FGFR三元复合物的荧光强度,但是5HPMF对GAGs中葡萄糖胺和半乳糖胺的含量及两者比例无明显影响,由此可推断5HPMF可能通过影响肺癌和结肠癌细胞表面GAGs结构而介导细胞内部信号转导。本研究为进一步探讨5HPMF对肺癌和结肠癌细胞表面GAGs二糖结构的变化与活性之间的相关性奠定了实验基础。     

贻贝对麻痹性贝类毒素的蓄积代谢研究进展

麻痹性贝类毒素（paralytic shellfish toxins,PSTs）能够导致贝类、鱼类等海洋生物染毒或死亡,危害海洋生态安全及人类健康。其中,贻贝具有强蓄积性特点,在国外可作为PSTs的指示性生物。近年来,我国因食用贻贝造成多起PSTs中毒事件成为安全关注重点,因此急需弄清其风险形成机理。本文通过综述我国近海贻贝等贝类中PSTs的风险程度、贻贝对不同产毒藻来源的PSTs的蓄积作用,分析环境因子对于蓄积代谢的影响,深入挖掘贻贝蓄积代谢特异性。进而聚焦贻贝代谢阶段的表达调控过程、影响因素、转化作用及方式等。未来应侧重于摸清我国目标区域贻贝等海洋贝类中PSTs基础风险规律和变化过程,并据此建立区域性PSTs风险防控技术,提高我国贻贝中PSTs风险的主动防控能力,对于保障消费者健康和海洋生态安全具有积极意义。     

红藻中红藻糖苷的研究进展

红藻糖苷是红藻中主要的光合作用同化产物。近年来发现,红藻中红藻糖苷的生理作用与蔗糖在高等植物中的作用类似,它们不仅是红藻中主要的小分子糖类物质,还在调控红藻中的渗透压等方面发挥着重要作用。红藻糖苷在细胞中的合成和代谢受到各因素的影响,其含量和结构也受到环境因素和来源地及红藻种类的影响。本文总结了近年来红藻中红藻糖苷的相关研究成果,分别对红藻糖苷的构型、生物合成、代谢、影响因素及生理作用等进行了阐述,从而为全面认识红藻糖苷在红藻中的生理作用提供参考。     

嗜冷酵母菌在低温下生长和适应及可能的机理

地球表面的许多地方温度都低于5℃,如海洋和两极地区。嗜冷微生物在这些地区大量存在。近年来,研究人员从不同的低温环境分离到多种嗜冷酵母菌,并且发现酵母菌比细菌适应低温环境的能力更强。嗜冷酵母菌在低温环境下的适应和生长机理已经成为研究热点。最新研究情况表明,脂类、酶、海藻糖、热激蛋白和抗冷冻蛋白等均与嗜冷酵母适应低温的机制相关。了解嗜冷酵母菌在低温下生长和适应的机理有助于发现低温环境的生命新现象和发现嗜冷酵母的用途。     

利用酒精酵母细胞表面展示技术制备活疫苗及其潜在应用

最近几年,出现把有关的基因在宿主表达之后的目的蛋白分泌并固定在细菌、病毒和酵母菌细胞表面上的技术一表面展示技术。在这些宿主中,酒精酵母菌是最佳的微生物。本文对利用酒精酵母细胞表面展示技术制备活疫苗的基本原理,在酵母细胞表面展示蛋白质的优点,以及哈维氏弧菌溶血素蛋白在酵母菌细胞表面上展示及其作为活疫苗的潜在应用作了综述。研究结果表明在酒精酵母菌细胞表面上展示的哈维氏弧菌溶血素蛋白在海洋动物中具有很好的免疫原性和免疫保护性。     

Multi-technique approach to characterise the effects of cryopreservation on larval development of the Pacific oyster (Crassostrea gigas)

Cryopreservation experiments were conducted on D-stage larvae of the Pacific oyster (Crassostrea gigas) to investigate the effects of two cryoprotectant solutions and three cooling rates on larval development from 1 to 22 days post-fertilisation. Cryoprotectant solutions were made up to final concentrations (after 1:1 dilution with larvae) of 10% ethylene glycol, 1% polyvinylpyrrolidone and either 0.2 or 0.4 M trehalose. Three cooling rates (0.5, 1 and 2 °C min^?1 between ?10 and ?35 °C post-holding) were tested in an orthogonal design with the two cryoprotectants. Results indicate that control larvae out-performed all cryopreservation treatments for survival, feeding consumption and shell length parameters. However, larvae exposed to 0.4 M trehalose did considerably better than those exposed to 0.2 M trehalose, regardless of cooling rate conditions. Scanning electron and light microscopy observations were used to assess larval morphology and organogenesis, indicating that treatments with surviving larvae were morphologically and developmentally similar to control larvae.     

Robust sliding mode control of a mini unmanned underwater vehicle equipped with a new arrangement of water jet propulsions: Simulation and experimental study

This paper presents dynamical modeling and robust control of a Mini Unmanned Underwater Vehicle (MUUV) equipped with a new arrangement of water jet propulsion. The water jet propulsion includes some advantages comparing with a propeller one, such as, reducing the number of required motors, desired number and arrangement of the propulsions, removing adverse torque and cavitation due to propeller rotation and etc. In order to model the proposed MUUV, the gray box method is used in such a way that the dynamical equation of motion is derived analytically by Euler-Lagrangian method, and then the hydrodynamic coefficients (such as added mass and drag coefficients) are derived by performing some tests in a Computational Fluid Dynamic (CFD) software. The dynamical model is used to simulate the MUUV system and also to design the proposed controllers, which are Feedback Linearization Controller (FLC) and Sliding Mode Controller (SMC). In order to investigate and compare the performance of the MUUV and the applied controllers, three types of tests including a desired signal tracking case and two desired path tracking cases are designed. To do so, a method is presented to obtain the desired signals from a desired path under predetermined conditions. Then, an MUUV prototype is designed and constructed in order to investigate the performance of the proposed water jet propulsions and controllers for regulation and tracking desired signal purpose, experimentally. As it is expected, the simulation and experimental results show better performance of the SMC compared to FLC. Furthermore, the experimental results reveal that the water jet propulsion is implementable to practical prototypes and also can be produced in an industrial level.     

Experience in measuring the wind-velocity profile in an urban environment with a Doppler sodar

The experience of long-term acoustic remote measurements of vertical wind-velocity profiles at two sites in Moscow is reported. Equipment performances and measurement conditions are described. Acoustic measurement features characteristic of a large city with high traffic noise and spurious reflections from buildings are discussed. Criteria and techniques of rejecting noisy and false signals are described as well as the methods of statistical data processing suitable in the case of a signal-to-noise ratio rapidly varying in time and a significant number of rejected signals. Preliminary results of measurements are given.     

Macrobenthic invertebrate responses to prolonged drought in South Africa's largest estuarine lake complex

St Lucia, the largest estuarine lake complex of its type in Africa, is characterised by natural physico-chemical spatial and temporal fluctuations. This estuary functions as an important nursery area making use of a number of different habitat types and associated environmental conditions. The system has been subject to a number of natural episodic events such as cyclonic flooding and cyclical droughts, the most current has persisted since 2001, resulting in almost permanent mouth closure. Furthermore, high levels of evaporation have reduced lake levels and resulted in compartmentalisation of the system for up to several years at a time. St Lucia is sensitive to evaporation and therefore to vast salinity fluctuations and hypersaline conditions. The upper reaches in North Lake are particularly sensitive to drying out and extended hypersaline events. The macrobenthos has been well studied, but no studies have concentrated on the entire system for such an extent of time. Macrobenthic samples were initially collected in 2004, again in 2005 and biannually from 2006 to 2008. This study was part of a larger multidisciplinary programme aimed at determining the effects of long term drought conditions on the ecology of the St Lucia system, and increasing current understanding of the system response to future catastrophic climatic events. Three areas were sampled (North and South Lake and Estuary) at five sites per area, over five years. Data were analysed by representing communities through time series depictions and discriminating sites and sampling periods to test multidimensional relationships. Linkages between biological distribution and selected environmental forcing variables were investigated. The system was found to be highly variable and supporting a large number of different habitats and co-occurring environmental conditions. This variability makes it difficult to discern spatial or temporal patterns in environmental conditions and macrobenthic ecology. However, some level of resilience to wide ranging environmental changes associated with drought is maintained. This study was able to determine that there exists a core of taxa able to persist even under shallow depth conditions and prolonged hypersalinity. These taxa clearly have a self recruiting strategy and are therefore not reliant on mouth opening to re-establish local populations. This finding alone has important bearing for future studies and management of the system under similar adverse conditions.     

Preparation of pure gum raw materials-low brown algae application

Octenylsuccinate starch ester,also called pure gum,is non-toxic and odourless modified starch which is widely used in many food fields.This study synthesized pure gum in a reaction kettle using the low molecular weight trehalose and octenyl succinic acid.An orthogonal test was carried out to find how the reaction factors aff ect the synthetization of octenylsuccinic acid polysaccharide ester and to optimize the reaction at single factor level.The optimal products were obtained using 1:2 of octenylsuccinic acid:alginic acid,catalysed by 0.1% p-toluenesulfonic acid catalyst for 1.5h at 200℃ under vacuum conditions.The gained product contains up to 46%of seaweed gel monoesters.The degree of esterification of the polysaccharide is controlled by the use of the small-molecule trehalose.Compared with the traditional methods,our process can reduce raw material cost and improve emulsification stability of pure gum.These all can significantly improve the market competitiveness of pure gum products.     

测量型GNSS接收机在海洋控制测量中的性能评估

在沿岸及海岛(礁)测量区域,利用TEQC软件,对几种常用测量型接收机采集的控制测量数据进行质量分析。通过从观测时间长度、卫星信号的信噪比、观测卫星总数、多路径效应、数据可利用率和周跳值等几个方面进行比较,选取了多路径效应值较大的观测数据进行了PPP解算,得出了一些有益结论,为今后的海洋控制测量作业提供良好的建议。     

光纤光谱仪的研制及其在海水营养要素检测中的应用

基于交叉非对称的czerny-Turner结构, 研制了一种微型光纤光谱仪, 采用光栅分光、线阵CCD探测光, 基于复杂可编程逻辑器件及PC104设计CCD数据采集电路, 采样结果通过PC104总线上传至PC104工控机, 光谱仪及数据采集电路集成为一光谱仪模块, 约为96mm(宽)×104mm(长)×18mm(高), 该模块与PC104工控机之间通过PC104总线以“针”和“孔”形式层叠连接, 在具有体积小、功耗低、采样速度快等优点的同时还具有极好的抗震性, 非常适合于野外恶劣工作环境下的在线使用。将其应用于海水中铁等痕量元素及营养盐在线检测仪, 试验结果良好。     

热带外太平洋通过海洋过程对热带太平洋的影响

利用MOM2海洋环流模式分别研究了年际和年代际尺度上热带外太平洋通过海洋过程对热带太平洋的影响.利用1945~1993年COADS资料的表面通量强迫海洋模式,积分46 a作为模式控制试验.取热带外太平洋海表面强迫为气候值做敏感性试验.将控制试验结果减去敏感性结果就可以得到热带外太平洋通过海洋过程对热带太平洋的影响.结果表明,年际尺度上,主要是海洋波动过程起作用,但总的海洋过程的影响较小.年代际尺度上,主要是副热带环流输送起作用,其中包括平均环流输送的温度异常以及异常环流输送的平均温度,并且后者贡献相对较大.年际和年代际尺度上,热带太平洋的温度异常主要发生在密度跃层附近.研究发现热带外南太平洋对热带和热带外太平洋之间的水量交换有影响,而热带外北太平洋的影响较弱.     

伊洛瓦底海豚被追逐时回声定位信号特征变化的初步分析

本文的研究基于文莱湾浅水域的一头野生伊洛瓦底海豚水声定位信号的调查数据。在记录期间,有一艘渔船突然开启发动机,惊扰了其附近的一头伊洛瓦底海豚,接着渔船开始两次连续追逐海豚。这期间海豚回声定位信号的变化情况被记录下来。当伊洛瓦底海豚受惊吓被追逐时,信号的声压级、每分钟嘀嗒声信号串的发生次数、每个嘀嗒声信号串中的脉冲个数和平均脉冲间隔都发生了相应的变化。平均的脉冲间隔在事件发生的瞬间立即增大,并在追逐期间呈现轻微下降趋势。脉冲间隔的增大对应着探测距离的增加,代表着海豚对未知区域的探索能力,制约着它的逃离速度。数据记录结果的分析表明,伊洛瓦底海豚会根据外界干扰对发出的回声定位信号进行调整,改变自己对潜在危险的探查能力。分析结果同时提醒我们需要随海豚生存环境的噪声进行管理,避免突然的发动机操作或者追逐它们。     

Use of the kurtosis statistic in the frequency domain as an aid in detecting random signals

Power spectral density estimation is often employed as a method for signal detection. For signals which occur randomly, a frequency domain kurtosis estimate supplements the power spectral density estimate and, in some cases, can be employed to detect their presence. This has been verified from experiments with real data of randomly occurring signals. In order to better understand the detection of randomly occurring signals, sinusoidal and narrow-band Gaussian signals are considered, which when modeled to represent a fading or multipath environment, are received as non-Ganssian in terms of a frequency domain kurtosis estimate. Several fading and muitipath propagation probability density distributions of practical interest are considered, including Rayleigh and log-normal. The model is generalized to handle transient and frequency modulated signals by taking into account the probability of the signal being in a specific frequency range over the total data interval. It is shown that this model produces kurtosis values consistent with real data measurements. The ability of the power spectral density estimate and the frequency domain kurtosis estimate to detect randomly occurring signals, generated from the model, is compared using the deflection criterion. It is shown, for the cases considered, that over a large range of conditions, the power spectral density estimate is a better statistic based on the deflection criterion. However, there is a small range of conditions over which it appears that the frequency domain kurtosis estimate has an advantage. The real data that initiated this analytical investigation are also presented.