同步辐射(软X射线)辐照玉米的细胞学效应研究

利用同步辐射(软X射线)辐照玉米自交系H65和H14D种子,研究其M1代的细胞学效应,并以60Co-γ射线作对照。结果表明,软X射线辐照处理后,不仅能够诱发玉米M1代根尖细胞内核畸变和染色体畸变,而且还能够诱发染色体多种类型的变异,其变异频率随辐照剂量的增加而增大,辐照剂量与细胞总畸变率呈正相关。软X射线对玉米根尖细胞的有丝分裂具有明显地抑制作用,辐照剂量与细胞分裂指数呈负相关。软X射线辐照的细胞学效应与γ射线基本相似,但在诱发的细胞畸变率和染色体变异类型上存在一定的差异。两个供试品系对辐射的敏感性为H14D>H65。     

同步辐射软X射线对枯草杆菌的诱变效应

采用同步辐射软X射线对枯草芽孢杆菌(Bacillus subtilis)1831菌株进行辐照处理,研究了不同剂量下3．1nm的软X射线对其芽孢的失活和诱变作用。结果表明：同步辐射软X射线对枯草杆菌芽孢的剂量存活曲线表现为典型的“肩型”,对芽孢的失活作用属于“单靶多击”方式,失活击中数等于3。根据脱脂牛奶平板上蛋白酶活力大小的测量统计,以变异系数作为诱变效应指标,软X射线对芽孢具有一定的诱变作用。     

热胁对海藻作用的荧光研究

本文用荧光方法研究了不同海藻对热胁的反应。在40℃的热处理下,红藻海膜（Halymenia Sinensis)的叶绿素荧光动力学曲线随时间呈规律性的变化,荧光强度先下降后上升,并有荧光的聚升现象,在达到最大值后,荧光就逐步跌落且不可逆转,此时藻体的荧光发射光谱发生了显著变化,藻红朊的荧光发射峰增高,蓝藻朊的发射下降,表明激发能由前者向后者的传递受阻,对绿藻孔石莼（Ulva pertusa)的比较研究表明,未见有荧光的聚升现象,且在受热过程中藻体的荧光光谱没有显著的变化,因而热胁对两类海藻的作用机制可能不全相同。     

药物设计与同步辐射

当代药物设计是通过阐明药物与靶标相互作用的机理,对药物先导化合物进行改造和优化。利用晶体X射线衍射的方法获得药物与靶标复合物的结构,为药物设计提供最直接有力的依据。同步辐射凭借其高强度、低发散性、波长可调谐性等得天独厚的优势,实现了对药物与靶标复合物结构的高通量测定,大大提高了基于结构的药物设计效率。     

培养液中钙对碳纳米材料细胞毒性作用机制的同步辐射初步研究

本工作研究了细胞培养液中钙离子和多壁碳纳米管,以及纳米碳黑的相互作用,采用钙荧光标记的显微成像技术和同步辐射X射线荧光技术,研究了HeLa细胞内钙离子浓度的增高及其相关机制。实验结果指出,细胞培养介质中的钙能被碳纳米颗粒(CNPs)大量吸附并载带进入细胞内,因此,CNPs向细胞内输送过量的钙离子可能是造成CNPs细胞毒性的重要原因。本工作为正确检测和评估碳纳米材料细胞毒性提供了新思路。     

同步辐射在显微CT中的应用

计算机X射线断层成像技术（CT）是利用X射线的穿透能力对物体进行扫描,所得信号经过反投影的算法而得到物体二维分布的一种成像方法,已经在医学诊断、工业探伤等领域广泛应用。但是由于实验室光源的低通量,光源点大小及其单色性等限制了其向高分辨发展,通常其分辨率在0．5mm左右。利用微焦点X射线源作为光源的显微CT分辨率可以达到微米量级,但是由于其光通量低且为非单色光,对不同样品有不同程度的束线硬化,影响了其真实分辨率。同步辐射作为一种新兴的光源有高亮度、高光子通量、高准直性、高极化性、高相干性及宽的频谱范围的特点,配合高分辨的X射线探测器,可以发展同步辐射显微CT,其分辨率可达10μm以下。利用同步辐射的高空间相干性开展位相衬度显微CT的研究,对低吸收物质也可以清晰三维成像。新建的上海光源的X射线成像及生物医学应用线站开展了三维显微CT方面的研究,经过初步试验,得到了较好的结果。     

安徽琅琊山铜矿蝶类重元素X荧光分析

为了研究安徽琅琊山铜矿环境中重元素污染的状况,利用同步辐射X射线荧光,对于采自安徽安徽琅琊山铜矿的9种蝴蝶的翅样品进行重元素分析。结果显示,9种蝴蝶体内重元素含量的差别变化明显,蝴蝶可以富集重元素Hg和Pb,其Cu、Zn元素的比值与环境污染程度相关。结果表明该方法样品处理简便,灵敏度高。     

几种海藻和赤潮藻的DCMU增益荧光比率及其与增殖速率的关系

本文研究了红藻海膜(Halymenia sinensis)，绿藻孔石莼(Ulva pertusa)，褐藻裙带(Underia pinnatifida)及蓝藻钝顶螺旋藻(Spirulina platersis)的DCMU增益荧光比率(FD／FN)。其中海膜的比率最高(3．9)，石莼及螺旋藻次之(2．5和2．8)，裙带(采自夏季)的比率最低(1.7)。脱水及热处理下和藻体老化时，FD／FN值显著下降。在实验室条件下分批培养的两种赤潮藻海洋原甲藻(Prorocertrum micans)和微小角毛藻(Chaetoceras minutissmus)，其增殖过程中最大增益荧光比率较最大增殖速率出现早，这一结果为赤潮的预报提供了依据。     

团头鲂成熟卵的超微结构和X射线微区分析研究

本文应用扫描电镜、透射电镜及X射线微分析技术,对团头鲂成熟卵的超微结构和离子元素含量进行了研究.结果表明,在团头鲂成熟卵的卵膜上具有许多卵膜孔,胞质内有丰富的管状嵴线粒体和游离核糖体;在质膜下的皮质区内有皮质小泡、微管和微丝结构.卵的表面含有Na、Mg、Al,Si、S、Cl、K和Ca,含量分别为6.65±0.47,0.39±0.06,5.51±0.83,0.51±0.01,76.41±0.94,9.24±1.39,0.71±0.24和0.96±0.05.卵的胞质内含有Na、Mg、Si、P、S、Cl、K、Ca和Fe,其含量分别为10.26±0.15,3.04±0.12,19.48±1.23,1.17±0.32,13.42±1.59,14.83±2.32,20.26±3.15,10.02±1.69和7.52±1.83.     

对X射线在医学影像中的影响研究

人们利用X线穿透能力强的特点,根据人体不同的组织对X线的吸收程度不同,均匀的X线穿透人体组织后,其不均匀的分布其实就是人体组织的投影。把这种成像技术应用在医学上,就可以得到患病处的位置信息。文章介绍了X线的原理及在医学影像上的作用。     

Preliminary Study of the Benthic Marine Algae on the Northern Bohai Sea Coast

The composition, distribution and seasonal variation of the benthic marine algae in the northern Bohai Sea coast were studied. 119 species of benthic marine algae were found in the northern Bohai Sea coast. They belong respectively to Cyanophyta, Thodophyta, Phaeophyta and Chlorophyta. The study showed that the marine algae flora of the northern Bohai Sea coast belongs to warm temperate in nature with considerable subtropical composition. There were 57 species of economic algae in the northern Bohai Sea coast and 7 newly recorded species.     

Investigation of elemental content distribution in femoral head slice with osteoporosis by SRXRF microprobe

A synchrotron radiation X-ray fluorescence microprobe analysis technique was used to scan a slice of the femoral head from its periphery to its center, via cartilage, compact, and spongy zones in order to determine the distribution and the way inorganic substances are lost in bone tissue. The sample preparation and experimental apparatus are described in detail. The quantitative computerized tomography of elemental distribution, such as Ca, P, K, Fe, Zn, Sr, and Pb in bone slice tissue, including cartilage, substantial compact, and substantial spongy, is investigated. Combined with the correlation among, P, K, Zn, Sr, and Ca, the route of loss of minerals and the physiological functions of some metal elements in bone are also discussed.     

Content of bioelements in the lungs and liver in rats with alimentary obesity

The synchrotron radiation X-ray fluorescence technique (SRXRF) was applied to the determination of K, Ca, Mn, Fe, Cu, Zn, Se, Br, Rb, and Sr concentrations in the liver and lungs in Wistar rats. The animals in the experiment included (1) healthy rats, (2) rats with alimentary obesity (AO), and (3) rats with alimentary obesity that were being given zinc sulphate with water for a long time (АО + Zn). Each group was divided into two subgroups. The experiment with the first subgroup was terminated with the animals in the state of physiological hunger and subsequent retrieval of liver and lung tissue, while the animals of the second subgroup were sacrificed two hours after ingestion of lard. The rats in physiological hunger manifested intergroup differences in the content of the bioelements (BEs) neither in the liver nor in the lungs. The rats with AO, as compared with the healthy animals, demonstrated in physiological hunger redistribution of inter-element correlations (IECs), which is an indirect reflection of sustained metabolic disorder. Additional zinc in the rats’ ration did not affect their body weight and the concentration of the BEs (including zinc) in the liver and the lungs. However, the IECs in the tissues of these animals in physiological hunger also changed. This redistribution differed from that in the rats with AO. The IECs soon after ingestion of lard also changed, which also reflects sustained changes in the metabolism in the animals.     

The influence of electrical stimulation of vagus nerve on elemental composition of dopamine related brain structures in rats

Recent studies of Parkinson's disease indicate that dorsal motor nucleus of nerve vagus is one of the earliest brain areas affected by alpha-synuclein and Lewy bodies pathology. The influence of electrical stimulation of vagus nerve on elemental composition of dopamine related brain structures in rats is investigated. Synchrotron radiation based X-ray fluorescence was applied to the elemental micro-imaging and quantification in thin tissue sections. It was found that elements such as P, S, Cl, K, Ca, Fe, Cu, Zn, Se, Br and Rb are present in motor cortex, corpus striatum, nucleus accumbens, substantia nigra, ventral tectal area, and dorsal motor nucleus of vagus. The topographic analysis shows that macro-elements like P, S, Cl and K are highly concentrated within the fiber bundles of corpus striatum. In contrast the levels of trace elements like Fe and Zn are the lowest in these structures. It was found that statistically significant differences between the animals with electrical stimulation of vagus nerve and the control are observed in the left side of corpus striatum for P (p = 0.04), S (p = 0.02), Cl (p = 0.05), K (p = 0.02), Fe (p = 0.04) and Zn (p = 0.02). The mass fractions of these elements are increased in the group for which the electrical stimulation of vagus nerve was performed. Moreover, the contents of Ca (p = 0.02), Zn (p = 0.07) and Rb (p = 0.04) in substantia nigra of right hemisphere are found to be significantly lower in the group with stimulation of vagus nerve than in the control rats.     

南海七种海藻多糖的抗病毒活性初步研究

采用体外细胞培养技术,对南海7种海藻多糖体外抗单纯疱疹Ⅰ型病毒(HSV-1)和柯萨奇B组3型病毒(CoxB3)活性进行研究。7种海藻多糖均表现出良好的抗病毒活性。其中,孔石莼多糖、蜈蚣藻多糖可明显抑制HSV-1,细胞病变半数抑制浓度(IC50)均为3.90μg/mL,选择指数(SI)分别达363和296.4。孔石莼多糖、小石花菜多糖可明显抑制CoxB3,IC50分别为1.95μg/mL和7.81μg/mL,SI分别为>1 025.6和212。同时理化实验结果表明,多糖样品均为硫酸酯多糖,其硫酸基和岩藻糖的含量与多糖的抗病毒效果密切相关。     

Inhibition of Icosanoid Production in MC/9 Mouse Mast Cells by n-3 Polyunsaturated Fatty Acids Isolated from Edible Marine Algae

The effects of two polyunsaturated fatty acids, 18:4n-3 and 16:4n-3 purified from the marine algae, Undaria pinnatifida and Ulva pertusa, on icosanoid production in MC/9 mouse mast cells were assessed. Both fatty acids suppressed the production of leukotriene B₄ (LTB₄), leukotriene C₄ (LTC₄), and 5-hydroxyeicosatetraenoic acid (5-HETE). The order of the suppressive activity for the two marine algae-derived fatty acids and three other common polyunsaturated fatty acids was as follows; 22:6n-3=18:4n-3=18:3n-3>20:5n-3=16:4n-3 for LTB₄; 22:6n-3=18:4n-3=18:3n-3>16:4n-3>20:5n-3 (no suppression) for LTC₄; 22:6n-3=18:4n-3>18:3n-3>20:5n-3=16:4n-3 for 5-HETE.     

The role of trace elements in the pathogenesis and progress of pilocarpine-induced epileptic seizures

X-ray fluorescence microscopy was applied for topographic and quantitative elemental analysis within the areas of the rat brain that undergo neurodegenerative changes in consequence of pilocarpine-induced seizures. Significant changes in levels of selected elements were observed in epileptic animals. They included an increased tissue content of Ca in the CA1 and CA3 regions of the hippocampus and in the cerebral cortex. The opposite relation was observed for the Cu level in the dentate gyrus and for Zn in the CA3 region of the hippocampus and in the dentate gyrus.     

底栖藻类对氮、磷去除效果研究

通过模拟实验探讨了污水处理中底栖藻类的群落结构、生长状况及其对氮(N)、磷(P)的去除能力。实验期间,被试藻类(丝状绿藻占优势)在污水中生长良好,培养5 d后收获的藻类生物量可达14.36±0.72 g;污水总氮(TN)、总磷(TP)含量分别由36.97±0.26 m g.L-1、2.88±0.02 m g.L-1降至1.44±0.09 m g.L-1、0.07±0.01 m g.L-1,对氨氮(NH4-N)和硝氮(NO3-N)的去除率亦达95%以上;藻体总凯氏氮(TKN)和TP含量分别为5.75±0.20%和1.5±0.22%。实验证明,底栖藻类对污水中的N、P营养有明显的去除效果,在污水的三级处理以及水体富营养化的防治方面具有较大的应用潜力。     

中国东海海洋微生物种群多样性初步研究

以东海海洋微生物群落为研究对象,用稀释平板分离法,从海泥和海水中得到542株分离物。随机选取58株发酵培养,将所有发酵菌株的16S rDNA基因扩增,并用限制性内切酶HinfI对PCR产物进行ARDRA(Amplified rDNA restriction analysis)多态性分析,共得到16种不同的操作分类单元(Operational Taxonom ic Un it,OTU)。其中OTU5和OTU7所包含的菌株分别占总分离物的32.7%和19.0%,为优势分离物。优势分离物的ER IC-PCR基因组指纹图分析表明,前者的19株分离物共有12种不同的指纹图类型,而后者的11株分离物有4种。结果显示,东海海域的海水和底泥具有明显的微生物种群多样性特征。