生物检材中乌头类生物碱的检验

 用薄层 (TLC)、高效液相 光电二极管阵列检测器 (HPLC/DAD)、动物实验等方法对生物检材中乌头生物碱进行检验 ,并对这些方法进行比较。结果发现 ,TLC法为此类药物检验筛选的首选方法 ,最小检出量为 0 3μg。在进行HPLC检测时 ,以乌头生物碱的特征紫外吸收光谱和动物实验结果为重要的定性手段 ,其特征吸收波长为 (2 2 8± 2 )nm和 (2 75± 2 )nm。乌头生物碱在 2mg/L～ 5 0mg/L时其峰面积与质量浓度有很好的线性 ,相关系数为 0 9996。经实际案件证明 ,方法准确、灵敏 ,可用于生物检材中乌头类生物碱的检验。     

微型集成化色谱仪

用微制造技术和色谱原理结合，以全新的概念和设计思维研制色谱仪一微型集成化色谱仪。这种仪器的整个色谱部分在基片上制成。集微型进样器，细内径毛细管柱和微型固体检测器于一体，功耗不过几瓦，重不过几百克，而分析速度比现有仪器提高近一个数量级，检测灵敏度可达１０＾－６Ｖ／Ｖ。这种仪器的制作过程类似半导体器件，能大批量，性能高度重复可靠、而成本极为低廉地制造出来，彻底改变传统色谱仪器的生产方式。本文给出这种仪     

A Quantum Chemical Study of N14 Cluster

Ab initio molecular orbital theory and density functional theory have been employed to study N₁₄ cluster with low spin at the HF/6-31G*, B3LYP/6-31G*, B3PW91/6-31G*, BP86/6-31G*, and BHLYP/6-31G* levels of theory. Twelve isomers were studied, including one previously investigated cage molecule. The most stable isomer of N₁₄ is a C _2h -symmetric molecule that contains two separated five-membered nitrogen rings connected by a —N=N—N=N— bridge. The second, third, and fifth most stable isomers each have one five-membered nitrogen ring. The theoretical results suggest that the five-membered nitrogen ring gives rise to a particularly stable structural unit, and the more side chains that the five-membered nitrogen ring links with, the less stable the structure will become.     

Stereoisomerism and complexation behaviour of functionalized p-tert-calix[6]-1,4-2,5-biscrown-4

p-tert-Calix[6]-1,4-2,5-biscrown-4 was subjected to functionalization by benzyl bromide or ethyl bromoacetate. Two pairs of disubstituted calix[6]biscrown stereoisomers were obtained. Their structures had been deduced from ¹H NMR and ESI-MS (electrospray ionization mass spectroscopy). One of the bisethyloxycarbonylmethylated derivatives 3a was further investigated by X-ray crystallographic analysis. Two-phase extraction experiments indicated that bisethyloxycarbonylmethylated derivatives exhibited high Cs⁺/Na⁺ selectivity. By ESI-MS and ¹H NMR experiments it was confirmed that 3a formed 1:1 complex with Cs⁺.     

矩形截面毛细管电泳和二维分离

在石英单晶表面制成矩矩截面毛细管柱中进行电泳实验。由于矩形柱比圆形柱有更大散热侧面积且石英单晶的导热性能远无于熔融石英，所以可施加较高的场强，不仅提高了柱效，而且缩矩了分离时间。两相交的通道之间形成自然连接，可实现二维分离，并消除死体积。     

Multi-focus optical fiber lens based on all-dielectric metasurface

A multi-focus optical fiber lens is numerically demonstrated based on an all-dielectric metasurface structure. The metasurface consists of an array of rectangular silicon resonators with varying widths in order to obtain the required phase distribution. The core diameter of the multimode fiber is large enough to contain sufficient resonance units. The spatial distribution of the dielectric resonators is dictated by spatial multiplexing, including interleaving meta-atoms and lens aperture division, to achieve multi-focus properties. The proposed optical fiber metalens can produce two or three focal points along the longitudinal direction with high focusing efficiency. The size of every focal point is close to the diffraction limit, and the relative intensity on each focus can be controlled by adjusting the number of the respective resonators. The proposed optical fiber lens will have a great potential in the fields of integrated optics and multifunctional micro/nano devices.     

Mitochondrial citrate accumulation drives alveolar epithelial cell necroptosis in lipopolysaccharide-induced acute lung injury

Necroptosis is the major cause of death in alveolar epithelial cells (AECs) during acute lung injury (ALI). Here, we report a previously unrecognized mechanism for necroptosis. We found an accumulation of mitochondrial citrate (citrate^mt) in lipopolysaccharide (LPS)-treated AECs because of the downregulation of Idh3α and citrate carrier (CIC, also known as Slc25a1). shRNA- or inhibitor–mediated inhibition of Idh3α and Slc25a1 induced citrate^mt accumulation and necroptosis in vitro. Mice with AEC-specific Idh3α and Slc25a1 deficiency exhibited exacerbated lung injury and AEC necroptosis. Interestingly, the overexpression of Idh3α and Slc25a1 decreased citrate^mt levels and rescued AECs from necroptosis. Mechanistically, citrate^mt accumulation induced mitochondrial fission and excessive mitophagy in AECs. Furthermore, citrate^mt directly interacted with FUN14 domain-containing protein 1 (FUNDC1) and promoted the interaction of FUNDC1 with dynamin-related protein 1 (DRP1), leading to excessive mitophagy-mediated necroptosis and thereby initiating and promoting ALI. Importantly, necroptosis induced by citrate^mt accumulation was inhibited in FUNDC1-knockout AECs. We show that citrate^mt accumulation is a novel target for protection against ALI involving necroptosis.Subject terms: Infection, Respiratory tract diseases     

Effect of Co-Existing Cations and Anions on the Adsorption of Antibiotics on Iron-Containing Minerals

The adsorption of antibiotics on minerals is an important process in their environment behavior. The adsorption behavior of antibiotics on iron-containing minerals and the effect of co-existing cations and anions were studied in this work. Magnetite, hematite, goethite and kaolin were selected as the representative minerals and characterized by SEM, XRD and BET. A total of eight antibiotics, including three quinolones, three sulfonamides and two mycins were chosen as the research targets. Results showed a higher adsorption amount of quinolones than that of sulfonamides and mycins on the surface of iron-containing minerals in most mineral systems. The adsorption isotherms of quinolones can be well fitted using the Freundlich models. The effects of five cations and five anions on the adsorption of quinolones were investigated, among which Mg²⁺, Ca²⁺, HCO₃⁻ and H₂PO₄⁻ mainly showed significant inhibition on the adsorption, while the effects of K⁺, Na⁺, NH₄⁺, Cl⁻, NO₃⁻ and SO₄²⁻ showed less. Natural surface water samples were also collected and used as media to investigate the adsorption behavior of quinolones on iron-containing minerals. The buffering capacity of the natural water kept the reaction solution at circumneutral conditions, and the adsorption amount was mostly promoted in the goethite system (from 0.56~0.78 μmol/g to 0.52~1.43 μmol/g), but was inhibited in the other systems (magnetite: from 1.13~1.33 μmol/g to 0.45~0.76 μmol/g; hematite: from 0.52~0.65 μmol/g to 0.02~0.18 μmol/g; kaolin: from 1.98~1.99 μmol/g to 0.90~1.40 μmol/g). The results in this work help to further understand the transportation and fate of antibiotics in an aqueous environment.     

太空育种射干的X射线荧光及X射线衍射分析和表征

联用X射线荧光光谱(XRF)和粉末X射线衍射(PXRD)方法,对我国独创的第4代太空诱变育种射干中多种元素种类和含量及晶态物质进行了研究。结果表明:太空组射干K元素含量比地面组、对照品分别提高了1.03和0.31倍,Mg元素分别提高了1.44和0.06倍,Ca,Mn和Fe元素含量比地面组分别提高了0.95,0.30和0.29倍,Al元素比地面组、对照组分别降低了38.5%和85.5%,并在射干中鉴别出一水草酸钙(CaC2O4.H2O)晶体,晶体含量是地面组<太空组<对照品。从而可得出结论:太空射干中人体必需的矿质元素比地面组都更接近或优于对照品。文章研究结果和方法对筛选品质优良的太空药材籽种和推广种植太空药材以及建立中药材质量评价标准,有积极的作用和重要意义。     

TEM喇叭馈源与共面馈源脉冲辐射天线性能比较

在反射面尺寸一定的情况下,优化设计了 TEM喇叭馈源与共面馈源脉冲辐射天线,并对比了两种天线的辐射性能。分析了反射面型脉冲辐射天线的工作机理,通过准静态近似,分别得到了两种天线的远区辐射场解析解。通过理论求解,得到了两种馈源在反射面口径造成的场分布,为天线结构设计提供参考。通过分析不同脉冲宽度时两种天线的辐射情况,比较了这两种馈源性能的优劣。完成了上述两种GW级高功率高效率馈源的研制,并开展了对比实验,实验结果与理论分析相吻合。