Investigation of antibacterial and cytotoxic potential of phenolics derived from Cistus incanus L. by means of thin-layer chromatography-direct bioautography and cytotoxicity assay

Cistus incanus L. (hairy rockrose) is a medicinal plant which belongs to the Cistaceae family and the Cistus genus, with a well established position in traditional medicine of the Mediterranean basin and the Middle East. It was the aim of this study to compare antibacterial activity of the phenolics derived from fourteen C. incanus samples of different origin (Turkey, Albania, Greece, and an unknown geographical location) obtained as herbal teas from a local market of diet supplements. This activity was assessed with the use of thin-layer chromatography–direct bioautography (TLC-DB) applied to crude extracts against the Gram negative naturally luminescent marine bacterium Aliivibrio fischeri and the Gram positive soil bacterium Bacillus subtilis as the test microorganisms. It was established that in spite of different origin of the investigated herbal samples, in qualitative terms their antibacterial activity was closely comparable and more strongly pronounced against the Gram positive than the Gram negative bacterium. Crude extract originating from one herbal specimen labelled A3 (sample no. 3 from Albania) underwent selective multi-step extraction of the phenolics, dividing them into six fractions (I to VI) that expectedly contain flavonoid aglycons, free phenolic acids, non-polar flavonoid glycosides, polar flavonoid glycosides, and phenolic acids obtained through the acidic and basic hydrolysis from the respective glycosides. Antibacterial activity of each A3 fraction was then assessed with the use of the same TLC-DB approach and it was established that the strongest effect was exerted by fractions I and II (flavonoid aglycons and free phenolic acids). Moreover, cytotoxic assay was performed for the crude C. incanus extracts against the human colon adenocarcinoma cells and a moderate yet well measurable cytotoxic effect was observed with all investigated C. incanus samples. In analogy to antibacterial activity, also in this case cytotoxic potential of all investigated crude C. incanus extracts was similar.     

Mesomorphic properties of cyanobiphenyl dimers with a central malonate unit

A series of cyanobiphenyl dimers attached via alkoxy spacers to a central malonate were prepared, and the mesomorphic behaviour was studied by differential scanning calorimetry (DSC), polarised optical microscopy and X-ray diffraction (Wide-angle X-ray scattering and Small-angle X-ray scattering). Depending on spacer lengths and substitution of the malonate, nematic and smectic A mesophases with pronounced odd–even effect were observed. C-2-unsubstituted malonates formed nematic phases for chain lengths C₆–C₁₄, while C₁₂ and C₁₄ homologues displayed additional smectic A phases. In contrast, malonates with fluorinated tails at C-2 displayed exclusively smectic A phases. Remarkably, the X-ray diffraction profile of the smectic A phase of the C-2-unsubstituted C₁₂ malonate showed a fundamental (001) and the corresponding third-order (003) diffraction peak, but no (002) reflection. Using Fourier analysis, the diffraction pattern was converted to an electron density profile, which was in good agreement with the proposed packing model of the SmA mesophase based on a horseshow- or hairpin-like conformation of the malonate.     

扫描定点法在Si/Mo多层膜材料深度剖面分析中的应用

用对比方式对分割成二等分的同一Ｓｉ／Ｍｏ多层非晶薄膜样品分别作了ＲＡＳ－ＰＯＩＮＴ ＭＯＤＥ和ＰＯＩＮＴ ＭＯＤＥ的二次离子质谱深度剖面分析,前者是把ＲＡＳ ＭＯＤＥ（扫描法）与ＰＯＩＮＴ ＭＯＤＥ（定点法）有效结合起来的一种方法,即所谓扫描一定点法。实验证明,扫描一定点法有效地克服了弹坑效应（Ｃｒａｔｅｒ ｅｆｆｓｃｔｓ）。     

A STUDY ON SNOW PROFILES AND SURFACE CHARACTERISTICS ALONG 6000km TRANSANTARCTIC ROUTE (Ⅰ)——THE "1990 INTERNATIONAL TRANS-ANTARCTIC EXPEDITION" GLACIOLOGICAL RESEARCH

Along a 5986 km route on Antarctic ice sheet from west to east, 106 snow pits with a depth ranging from 1.0—2.0 m have been dug by the first author of this paper, the Chinese member of the "1990 International Trans-Antarctic Expedition". The basic physical characteristics of the surface layer of the ice sheet on a large scale are obtained through the observations of snow profiles at these snow pits. The sastrugi shapes and major axis azimuths have also been observed or measured on the way. Analysis for these observation data shows that in West Antarctica the meltwater infiltration-congelation is obvious and the annual precipitation is larger than that in East Antarctica, which implies that climate in West Antarctica is warmer, more humid and influenced more greatly by the South Ocean than that in East Antarctica. Radiation ice-glazes frequently found in snow profiles indicate that even in East Antarctica under very low temperatures, surface "melting" occurs in summer due to the long-time solar radiatio     

聚丙烯酰胺电泳法测定小麦种子纯度方法的改进

使用SE-2000A型对小麦、玉米专用的电泳仪，对GB/T3543.5-1995聚丙烯酰胺电泳法测定小麦种子纯度方法的样品提取、点样量及电泳条件进行了改进，结果表明：改进后使麦醇蛋白溶蛋白电泳图谱的蛋白质区带界限更明显，公共带和特征带清晰、可靠，且样品提取时间缩短了23.5h。     

Comparative plasma SNMS and AES measurements on ceramic powders and fibres

SNMS depth profiles of layers of 0.4–0.8 m sized Si₃N₄, BN and partly SiC-coated B₄C powder particles and of 10 m sized SiC fibres are obtained without great expenditure on time and specimen preparation. Close contact with Au foil provides for electrical conductivity. Averaged depth profiles of a great number of particles or fibres are obtained. AES serves as a comparative method; the carrier-gas heat extraction (inert gas fusion) technique is used for the semiquantification of OH signals in SNMS. Esterification of surface OH with ethanol during suspension is not detectable. Hydrolyzation or oxidation reactions having penetrated through the bulk of BN particles cause qualitatively different depth profiles than found on Si₃N₄ particles carrying a nm thin natural (hydr-)oxidic layer. The effects of preparative surface reactions like additive coating (SiC on B₄C particles), etching and oxidation (of SiC fibres) can be monitored. Quantification attempts yield standard deviations between 10 and 50%.Presented on the 15. Kollquium über Werkstoffanalytik, Vienna, May 27–29, 1991     

佛克脱光谱线型干涉图的理论及其应用研究

在一般压强的条件下,佛克脱光谱线型(高斯光谱线型和洛伦兹光谱线型的卷积)是最接近实际的光谱线型,但由于其没有具体的表达式,所以在实际应用中常采用各种近似来表示佛克脱光谱线型。文章未采用任何近似,计算了佛克脱光谱线型干涉图的具体表达式,表明虽然佛克脱光谱线型没有具体表达式,但其干涉图是可以严格求解的。而且其变换结果为一实函数,与高斯光谱线型和洛伦兹光谱线型的变换结果的表达式非常相似,因而可以进行谱线综合展宽的各种计算,而不是像有的文献所预言的有实部和虚部两部分,给计算带来困难。计算结果与实验结果一致。作为应用的一个实例,作者指出了其在大气风场测量中的重要应用。此计算对气体展宽在傅里叶变换光谱仪中的应用方面具有非常重要的意义。     

佛克脱线型HeⅠ 1 083.0 nm的有效后向散射截面的理论研究

考虑到碰撞展宽导致的洛伦兹线型,理论上研究了佛克脱线型(高斯线型和洛伦兹线型的卷积)HeⅠ 1 083.0 nm辐射线的后向散射截面和有效后向散射截面,HeⅠ 1 083.0 nm辐射线实际上由三条非常接近的1 083.034,1 083.025和1 082.908 nm辐射线组成,文章给出了此3条辐射线的有效后向散射截面的曲线及其峰值,得到的10-16数量级与预言的数量级相一致。此研究比以前假定HeⅠ 1 083.0 nm辐射线为高斯线型更接近实际,从而为共振雷达探测热成层亚稳态He提供了更全面翔实的理论基础。文章还给出了HeⅠ 388.9 nm和HeI 318.8 nm辐射线的有效后向散射截面的曲线及其峰值,得到它们的有效后向散射截面比HeI 1 083.0 nm辐射线的小,此结论与实验结果相一致。     

Ratio of Real to Imaginary for pp and (p)p Elastic Scatterings in QCD Inspired Model

We use the QCD inspired model to analyze the ratio of the real to the imaginary for pp and pp elastic scatterings. A calculation for the ratio of the real to the imaginary is performed in which the contributions from gluongluon interaction, quark-quark interaction, quark-gluon interaction, and odd eikonal profile function are included. Our results show that the QCD inspired model gives a good fit to the LHC experimental data.     

Blow-up rate and profile for a class of quasilinear parabolic system

This paper deals with positive solutions to a class of nonlocal and degenerate quasilinear parabolic system with null Dirichlet boundary conditions. The blow-up rate and blow-up profile are gained if the parameters and the initial data satisfy some conditions.