活性X-3B红染料的生物富集因子及在作物体内的分配

有机染料已成为中国地表环境中重要的一大类有机污染物.采用水培和土培两种微宇宙生态试验方法,对活性X-3B红染料的生物富集因子(BCF)及在作物体内的分配进行了研究.结果表明,在试验浓度范围内,该化合物BCF为252.1～409.4根据这一数值和有关评判依据,可知一般生物体对该有机染料具有中等水平的富集能力,各试验作物地下部分对活性X-3B红染料的积累比地上部分至少超出10倍,尤其以根部作为食物的萝卜更为明显从土壤-作物系统的完整性进行比较和以地上籽实为粮食的作物来看,各作物及其不同部位对活性X-3B红染料的积累浓度大致为大豆(棕壤)＞小麦(褐土)＞水稻(水稻土),根>茎秆＞叶＞籽实(不含壳);而从这些作物在其籽实中积累活性X-3B红染料来看,以累积量为最低的水稻籽实中的最大浓度也可达到23.33μg·lg^-1.可见,该有机染料对环境污染的生态风险不容忽视.     

活性X—3B红染料的生物富集因子及在作物体内的分配

有机染料已成为中国地表环境中重要的一大类有机污染物,采用水培和土壤两种微宇宙生态试验方法,对活性X－3B红染料的生物富集因子（BCF）及在作物体内的分配进行了研究,结果表明,在试验浓度范围内,该化合物BCF为252．1－409．4,根据这一数值和有关评判依据,可知一般生物体对该有机染料具有中等水平的富集能力,各试验作物地下部分对活性X－3B红染料的积累比地上部分至少超出10倍,尤其以根部作为食物的萝卡更为明显,从土壤－作物系统的完整性进行了比较和以地上籽实为粮食的作物来看,各作物及其不同部位对活性X－3B红染料的积累浓度大致为大豆（棕壤）＞小麦（褐土）＞水稻（水稻土）,根＞＞茎秆＞叶＞籽实（不含壳）;而从这些作物在其籽实中积累活性X－3B红染料来看,以累积量为最低的水稻籽实中的最大浓度也可达到23．33μg.kg^-1,可见,该有机染料对环境污染的生态风险不容忽视。     

FISH probes for the detection of the parasitic dinoflagellate Amoebophrya sp. infecting the dinoflagellate Akashiwo sanguinea in Chesapeake Bay

A comparison of the small subunit rRNA sequences of a Chesapeake Bay strain of the dinoflagellate Akashiwo sanguinea and the dinoflagellate Amoebophrya sp. parasitizing it revealed several potential target sites that could be used to detect the parasite through in situ hybridization. The fluorescence of probed cells under various conditions of hybridization was measured by using a spot meter on a Nikon UFX-II camera attachment so that the effect of various hybridization parameters on probe binding could be determined. Probes directed against both the junction between helices 8 and 11 and helix 46 could detect the parasite, although the helix 8/11 probe produced a stronger signal under the conditions tested. The fluorescence of the probed cells increased with increasing hybridization time up to approximately twelve hours. The background fluorescence was lower at the wavelengths used to detect Texas Red than at those used to detect fluorescein, so probed cells were more distinct when Texas Red was used as the label. Cells stored in cold paraformaldehyde for a year still bound the probes. Young stages of the parasite could be seen more readily after in situ hybridization than after protargol impregnation.     

Pathology of skeletal muscle in mitochondrial disorders

Muscle histology is an essential component of the diagnostic work-up for mitochondrial cytopathies and is very important in both ruling in disease as well as ruling out the disease (i.e., alternate diagnoses). A muscle biopsy method must provide tissue for histology, electron microscopy, enzymes and DNA and this can be obtained with a suction-modified 5 mm needle. Proper embedding and processing is important for optimal diagnostic yield. The essential stains for mitochondrial histology remain the modified Gomori trichrome, cytochrome oxidase, succinate dehydrogenase, and NADH. Electron microscopy can be helpful in selected cases, however, the decision to perform this on all samples remains a contentious issue. Some cases of mitochondrial cytopathy may show no abnormalities on histology or electron microscopy (i.e., LHON), whereas, other conditions can mimic mitochondrial disease through secondary mitochondrial changes (i.e., inclusion body myositis). Athletes show evidence of increased mitochondrial numbers but do not normally develop ragged red fibers or paracrystalline inclusions. Aging is associated with an accumulation of mitochondrial abnormalities and is an important factor to consider in the interpretation of the sample. For example, biopsies in young children with mitochondrial disease may be normal at the histological level and otherwise healthy older adults can show mitochondrial changes such as ragged red and COX-negative fibers.     

Use of serially coupled capillary columns with different polarity of stationary phases for the separation of the natural complex volatile mixture of the marine red alga Corallina elongata

Separation of a complex of natural volatile compounds using serially coupled capillary columns with different polarity of stationary phases by gas chromatography–mass spectrometry from the medicinal marine red alga Corallina elongata is reported. Nearly 200 hydrocarbons, halogen compounds, fatty acids, and other metabolites were found. Using this gas chromatography procedure we demonstrate the successful separation of different volatile organic compounds.     

比较染色体涂色显示小熊猫(Ailurus fulgens)具有高度保守的核型

以狗的整条染色体特异探针,通过比较染色体涂色（Comparative Chromosome Painting）,建立了小熊猫和狗的比较染色体图谱。狗的38条常染色体探针在小熊猫染色体上共检出71个同源片段。其中狗的18条常染色体每一条在小熊猫染色全上各有1个同源片段,其余的20条常染色体每一条在小熊猫染色体上各有2至5个同源片段。广泛的染色体结构重排造成了小熊猫与狗的核型差异：至少需要经过28次断裂,49次融合,4次倒位才能将狗的核型（2n=78）“转变”为小熊猫的核型（2n=36）。结合已发表的狗与家猫的比较染色体图谱,我们推测：小熊猫与家猫之间共存在26个同源片段,二者的核型之间显示了较高的同源性。通过比较分析狗的染色体同源片段在小熊猫与家猫染色体上的分布和排列,可以看出：4次染色体易拉,2次倒位造成了小熊猫与家猫的核型差异。我们的工作进一步证实了利用基因组高度重排的物种（如：狗）的染色体特异探针与核型保守的物种（如：家猫、水貂、小熊猫）进行比较染色体涂色研究,不但可以准确快速地鉴别物种进化过程中所发生的染色体间的结构重排,而且还可揭示染色体内的结构重组。     

Antiviral effect of red microalgal polysaccharides on Herpes simplex and Varicella zoster viruses

The cell-wall sulphated polysaccharide of the red microalga Porphyridium sp. has impressive antiviral activity against Herpessimplex viruses types 1 and 2 (HSV 1, 2) and Varicella zoster virus(VZV). Treatment of cells with 1 g mL^-1 polysaccharideresulted in 50% inhibition of HSV-infection as measured by the plaqueassay. Inhibition of the production of new virus particles was also shownwhen pre-infected cell cultures were treated with the polysaccharide. Inaddition, there was indirect evidence for a strong interaction between thepolysaccharide and HSV and a weak interaction with the cell surface.Depending on the concentration, the polysaccharide completely inhibitedor slowed down the development of the cytopathic effect in HSV or VZVpreinfected cells, but did not show any cytotoxic effects on Vero cells evenwhen a concentration as high as 250 g mL^-1 was used. Itseems therefore that the polysaccharide is able to inhibit viral infection bypreventing adsorption of virus into the host cells and/or by inhibiting theproduction of new viral particles inside the host cells. Thus, this alga seems tobe a good candidate for the development of an antiviral drug.     

南方红壤丘陵区油桐人工林土壤水分动态

利用时域反射仪(TDR)定位监测方法,研究了南方红壤丘陵区油桐人工林土壤水分动态规律.结果表明:不同月份间土壤蓄水量差异达极显著水平,研究时段内土壤水分动态变化可划分为土壤水分积累期、土壤水分消耗期和土壤水分稳定期3个时期;油桐人工林土壤水分垂直变化显著,且不同季节的变化规律各异;土壤蓄水量与大气相对湿度(RH)、大气温度(t)、饱和水汽压差(VPD)、降雨量(R)等气象因子显著相关(P<0.05); 次降雨后,土壤水分损失率与干旱天数呈显著的双曲函数关系,土壤蓄水量与雨后干旱天数呈显著的线性负相关(P<0.05);在次降雨后的持续干旱条件下,土壤水分损失随着土层深度的增加逐渐趋于平缓.     

华南赤红壤无机复合肥氮磷淋失特征

采用室内土柱淋溶模拟试验,研究了不同施肥水平下无机复合肥中氮和磷在华南赤红壤中的淋失特征.结果表明: 铵态氮、硝态氮和总氮淋失量均随施肥量增加而提高;肥料中氮的淋失率在36.8%～49.2%之间,总氮淋失量（y）与施肥量（x）之间的回归方程为y=0.3667x+66.483（R²=0.992）;铵态氮和总氮的淋失主要集中在前5次淋洗,硝态氮的淋失持续时间更长.施肥量对可溶性磷淋失量无显著影响,但颗粒磷和总磷淋失量均随施肥量增加呈上升趋势;肥料磷淋失率在0.002%～0.010%之间,总磷淋失量（y）与施肥量（x）之间的回归方程为y=7e^-5x+0.0538（R²=0.931）;磷的淋失动态与氮显著不同,为缓慢的持续累积过程.硝态氮与铵态氮淋失量比值和可溶性磷与颗粒磷淋失量比值均随施肥量增加呈下降趋势.     

大鹏湾维生素B1、B12与赤潮

海湾及近海水域 ,因某些浮游生物爆发性繁殖引起的赤潮异常现象时有发生 ,已构成水产资源的严重破坏。为弄清赤潮发生的机理 ,已有许多作者进行过研究 ,现已知水温、盐度、溶解氧、ｐＨ、Ｎ、Ｐ ,以及Ｆｅ、Ｍｎ、Ｓｅ等微量元素都是发生赤潮的重要环境因子[1 ]。近年来通过生态实验研究 ,发现维生素Ｂ1 、Ｂ1 2 (以下简称Ｂ1 、Ｂ1 2 )亦有促进赤潮生物生长繁殖的作用[2 ]。本文报道 1 991年对大鹏湾海域水样中Ｂ1 、Ｂ1 2 含量的测定结果 ,并对赤潮发生与其相关性进行探讨。1　采样布点和分析方法1 .1　采样布点大鹏湾盐田海域的Ｓ0 、Ｓ1…