用星点设计-效应面法优化锥栗总黄酮超声提取工艺

为了优选锥栗中总黄酮的超声提取工艺条件,以乙醇体积分数、提取时间、液固比为试验因素,以锥栗总黄酮的提取率为考察指标,在单因素试验的基础上,采用星点设计–效应面法(CCD-RSM),对锥栗总黄酮的提取工艺条件进行了优化试验。结果表明,锥栗总黄酮的最佳提取工艺条件为:80%乙醇,超声提取20min,固液比为24,提取温度为50℃。按此工艺提取,总黄酮的提取率为0.0685%;且此方法操作简便,结果稳定,预测性良好。     

南极磷虾渔船船速对科学探鱼仪有效探测深度的影响

渔业资源声学调查评估的基本条件之一是科学探鱼仪的有效探测深度可以覆盖目标的主要分布水层.针对利用渔船采集声学数据开展南极磷虾资源调查评估,本研究基于后处理方法获得声学数据背景噪声强度,建立一种科学探鱼仪有效探测深度的评估方法,并以南极磷虾渔船"福荣海"轮为例,评估船速变化对该船船载Simrad EK60型科学探鱼仪(3...     

An enrichment microsphere immunoassay for the detection of <Emphasis Type="Italic">Pectobacterium atrosepticum</Emphasis> and <Emphasis Type="Italic">Dickeya dianthicola</Emphasis> in potato tuber extracts

An enrichment microsphere immunoassay (MIA) was developed, based on the Luminex xMAP® technology, for the simultaneous (duplex) detection of Pectobacterium atrosepticum (former name Erwinia carotovora subsp. atroseptica) (Pca) and Dickeya dianthicola (former name Erwinia chrysanthemi) (Dcd) in potato plant extracts. Target bacteria in the extracts were enriched for 48 h in a semi-selective broth containing polypectate under low oxygen conditions. Samples were subsequently incubated with antibody-coated colour-coded microspheres (beads) and with secondary antibodies conjugated with Alexa Fluor® 532, a reporter dye. Samples were analyzed with the Luminex analyzer, in which one laser identified each microsphere and another laser the reporter dye conjugated to the secondary antibodies. The assay required minimal sample preparation, could be completed in 1 h, was performed in 96 wells microtitreplates and required no wash steps. The limit of detection for the duplex enrichment MIA was 100–1000 cfu ml^?1, which was a hundred times lower than of an enrichment-ELISA. Without enrichment, the sensitivity of MIA and ELISA was largely similar and ranged between 10⁶ and 10⁷ cells ml^?1. No difference in sensitivity was found between a MIA in a single or duplex format. In a comparative test with non-infected potato plant extracts and extracts from plants infected with Pca or Dcd, results of the enrichment MIA correlated well with those of the enrichment ELISA and enrichment PCR. These results indicate that MIA can be reliably used for multiplex detection of soft rot Enterbacteriaceae in crude potato plant extracts. The technology is an attractive and cost-effective alternative to other detection methods, including ELISA.     

Establishment of a Method to Measure Length of the Ulnar Nerve and Standardize F-wave Values in Clinically Normal Beagles

We designed a new method of measuring the length of the ulnar nerve and determining standard values for F-wave parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely measured to determine F-wave latency and conduction velocity. The length of the forelimb has served as the length of the ulnar nerve for F-wave assessments, but report indicates that F-wave latency is proportional to the length of the pathway traveled by nerve impulses. Therefore, we measured the surface distance from a stimulus point to the spinous process of the first thoracic vertebra (nerve length 1) and the anterior horn of the scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade acromion. The correlation coefficients between the shortest F-wave latency and the length of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the highest value. Furthermore, the anterior horn of the scapula was easily palpated in any dog regardless of well-fed body. We concluded that nerve length 2 was optimal for measuring the length of the ulnar nerve.     

Physical and biological consequences of a climate event in the central North Pacific

Climatic changes over the North Pacific which began in the mid 1970s, peaked in the early 1980s, and ended by the late 1980s, appear to have altered productivity at various trophic levels in the marine ecosystem in the central North Pacific. The climatic change resulted in increased mixed layer depth and the frequency of deep mixing events, particularly during January-March. A number of biological time series for species ranging from primary to apex levels in the North-western Hawaiian Islands, show corresponding declines in productivity of 30–50% from the early 1980s to the present. We hypothesize that during the early 1980s, increased mixing due to the climate event resulted in greater nutrient input into the euphotic zone and ultimately increased ecosystem productivity. Productivity over a range of trophic levels declined when the climate event ended.     

池塘投饵机控制系统

根据北方池塘投铒的实际要求，结合电路控制的各项性能，研制开发了一种新型的投铒机控制系统。应用逻辑电路和定时器电路进行控制，使用拨码开关技术设置定时时间、自动重复启动的间隔时间和投铒的各项参数，并具有延时投铒功能。操作简单直观、定时准确、抗干扰能力强，解决了定时定量、准确投喂的问题，避免了铒料投喂的浪费。     

Spillover effects of a Mediterranean marine protected area on the European spiny lobster Palinurus elephas (Fabricius, 1787) resource

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Site of acid-base relevant ion transfer in the gills of rainbow trout (Oncorhynchus mykiss) exposed to environmental hypercapnia

In order to delineate the contribution of primary vs. secondary circulatory circuits in the gill for acid-base and ionic regulation, the flow and composition of the fluids in the central venous sinus (CVS) and the systemic circuit of rainbow trout were studied by application of a previously developed microcannulation technique during normocapnic and hypercapnic conditions. The average haematocrit (Hct) of blood from dorsal aorta (DA) and sinus venosus (SV) ranged from 20.1 to 26.7%, whereas average Hct in the fluid from the branchial vein (BV), representing drainage from the central venous sinus (CVS), was in the range of 4.2 to 7.0%. Under normocapnic conditions, the largest fraction of cardiac output, 92.9%, was directed through the systemic vascular circuit, whereas the CVS circuit was perfused with 7.1 % of cardiac output. Hypercapnia did not significantly affect the blood flow distribution between the two circuits. The pattern of acid-base regulation in dorsal aortic blood reflected the characteristic response of fish exposed to environmental hypercapnia. Upon initiation of environmental hypercapnia (2% CO₂), plasma P_{CO 2} was elevated in all three flow compartments (CVS, DA, SV), inducing an extracellular respiratory acidosis of about 0.4 pH units. pH and [HCO₃ ^-] values in the DA were consistently lower, than those for both CVS and SV sites throughout the hypercapnic period. During the 8h of exposure plasma bicarbonate concentration was elevated by about 12 mM, complemented by a fall in extracellular [Cl^-] of about 10 mM in all three compartments. The amount of HCO₃ ^- gained at the CVS site during 8h of hypercapnia (3.3 mmol · kg^-1) exceeds the amount accumulated in the extracellular space (2.1 mmol·kg^-1), suggesting the CVS as the main site of ionic acid-base regulation in trout.     

黄海中部小黄鱼的食物组成和摄食习性的季节变化

根据2001年3月至2002年1月在黄海中部海域进行的4个季节的定点底拖网调查,应用聚类分析、单因素方差分析和列联表检验等方法,对小黄鱼(Pseudosciaena polyactis Bleeker)的食物组成和摄食的季节变化进行研究.结果表明,小黄鱼摄食的饵料种类有30余种,甲壳类(磷虾类和虾类)和鱼类是其主要的饵料类群,二者在食物中所占的重量百分比之和为97.45%.优势饵料种类有太平洋磷虾(Euphausia pacifica)、脊腹褐虾(Crangon affinis)、细螯虾(Leptochela gracilis)和赤鼻棱鳀(Thryssa kammalensis).小黄鱼的摄食强度有显著的季节变化,秋季最高,春季和冬季较低.食物组成也随季节的不同而有所变化,夏季主要以虾类为食,其它季节则主要以磷虾类为食.聚类分析的结果表明,小黄鱼春、夏季的食物组成与秋、冬季相比,存在较大差异.通过与历史资料进行比较发现,黄海小黄鱼的食物组成发生了较大的变化,其中鳀鱼(Engraulis japonicus)在食物中所占的比例有明显的下降.     

耦合MOP-FLUS模型的滇中城市群“三生”空间格局优化

生产空间、生活空间、生态空间之间联系紧密,决定国土空间的最高演化目标,为了协调区域经济社会的发展,通过构建符合城市群发展实际的“三生”空间分类体系划定国土空间; 基于目标条件与情景设定,通过MOP模型实现“三生”空间综合效益最大化; 利用FLUS模型优化“三生”空间布局,并采用景观格局指数对其优化结果进行了分析评价。结果表明:优先满足生产和生活空间发展情景的生态效益最低,城镇化进程加快的同时生态空间发展受到抑制,生态环境脆弱; 优先满足生态空间发展情景的经济效益最低,生态环境虽然得到良好保护,但同时生产与生活空间面积占比较小,分布破碎,不利于区域经济发展; “三生”空间均衡协调发展情景的经济效益提高4.46%,生态效益提高1.87%,空间布局均衡统一。因此该情景能够合理平衡生态建设与经济发展,在丰富生态过程和格局结构上具有优越性,可为滇中城市群国土空间资源配置、“三生”空间优化等决策提供一定的参考和借鉴。