Multinuclear NMR and FTIR studies of new polyoxaalkyl esters of lasalocid and their complexes with lithium and sodium cations

Three new polyoxaalkyl esters of lasalocid are synthesized. Their ability to form complexes with Li(+) and Na(+) cations is studied using multinuclear NMR methods, FTIR spectroscopy in the middle and far IR regions, and mass spectrometry. It is found that lasalocid esters form only 1:1 complexes with the metal cations. The results of the NMR study in pyridine show that the polyoxaalkyl chain of the ester does not influence the complex formation of the lasalocid part of the esters. The reason for this is the competition of the pyridine molecules in the complexation process of metal cations. In chloroform the properties of the complex formation have changed and the oxaalkyl chain plays an important role within the complexation process, as demonstrated by the dependence of the respective continuous absorptions in the far IR region on the length of the oxaalkyl chain (i.e., on the number of the oxygen atoms in the chain). The modifications of the lasalocid molecule influences the complexation of the metal cation and probably the interactions with the membrane. An increase in antibiotic activity is found as a consequence of these changed interactions.     

五峰尖贝原植物形态及有效成分研究

通过对湖北民间常用中药——五峰尖贝的产地调查,系统地对其原植物及药用器官(鳞茎)的形态及有效成分进行了研究。确定五峰尖贝为百合科(Liliaceae)植物太白贝母(Fritilliaria taipaiensis P.V.Li)。     

清胆颗粒利胆作用的实验研究

目的：通过研究清胆颗粒对正常大鼠及模型动物胆汁及病理组织的影响,确定其利胆功效,为临床应用提供依据.方法：采用胆管引流法测定清胆颗粒对正常大鼠胆汁量的影响;应用石胆酸（lithocholic acid,LCA）造成豚鼠胆囊炎模型,测定其对模型动物肝重、肝指数、胆囊容积及胆囊病理组织的影响.结果：清胆颗粒能显著增加正常大鼠胆汁流量,明显减轻模型动物肝湿重和肝指数,缩小胆囊容积,能明显降低胆汁中TB、DB及UCB/TB含量,对Ca^2＋增高有明显的抑制作用,对模型动物胆囊粘膜上皮增生有明显的抑制作用.结论：清胆颗粒具有显著的利胆作用.     

Tunable white light emission from single‐phased Li2SrSiO4:Dy3+ phosphors by co‐doping with Eu3+

A series of single‐phase full‐color emitting Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ phosphors were synthesized by solid‐state reaction and characterized by X‐ray diffraction and photoluminescence analyses. The samples showed emission peaks at 488 nm (blue), 572 nm (yellow), 592 nm (orange) and 617 nm (red) under 393 nm excitation. The photoluminescence excitation spectra, comprising the Eu–O charge transfer band and 4f–4f transition bands of Dy³⁺ and Eu³⁺, range from 200 to 500 nm. The Commission Internationale de I'Eclairage chromaticity coordinates for Li₂Sr_0.98−xSiO₄:0.02Dy³⁺,xEu³⁺ phosphors were simulated. By manipulating Eu³⁺ and Dy³⁺ concentrations, the color points of Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ were tuned from the greenish‐white region to white light and eventually to reddish‐white region, demonstrating that a tunable white light can be obtained by Li₂Sr_1−x−ySiO₄:xDy³⁺,yEu³⁺ phosphors. Li₂Sr_0.98−xSiO₄:0.02Dy³⁺, xEu³⁺ can serve as a white‐light‐emitting phosphor for phosphor‐converted light‐emitting diode. Copyright © 2014 John Wiley & Sons, Ltd.     

Insight into the Electrode Mechanism in Lithium‐Sulfur Batteries with Ordered Microporous Carbon Confined Sulfur as the Cathode

In lithium‐sulfur batteries, small S_2–4 molecules show very different electrochemical responses from the traditional S₈ material. Their exact lithiation/delitiation mechanism is not clear and how to select proper electrolytes for the S_2–4 cathodes is also ambiguous. Here, S_2–4 and S₈/S_2–4 composites with highly ordered microporous carbon as a confining matrix are fabricated and the electrode mechanism of the S_2–4 cathode is investigated by comparing the electrochemical performances of the S_2–4 and S_2–4/S₈ electrodes in various electrolytes combined with theoretical calculation. Experimental results show that the electrolyte and microstructure of carbon matrix play important roles in the electrochemical performance. If the micropores of carbon are small enough to prevent the penetration of the solvent molecules, the lithiation/delithiation for S_2–4 occurs as a solid‐solid process. The irreversible chemically reactions between the polysulfudes and carbonates, and the dissolution of the polysulfides into the ethers can be effectively avoided due to the steric hindrance. The confined S_2–4 show high adaptability to the electrolytes. The sulfur cathode based on this strategy exhibits excellent rate capability and cycling stability.     

Correlation Between Atomic Structure and Electrochemical Performance of Anodes Made from Electrospun Carbon Nanofiber Films

A systematic study is made of the effect of the nitrogen species on the performance of Li‐ion storage and the capacities of carbon‐based anodes in Li‐ion batteries (LIBs). Electrospun carbon nanofiber (CNF) films are fabricated for use as binder‐free electrodes using a polyacrylonitrile precursor. When the CNF films are subjected to carbonization, transformation occurs from an amorphous to a graphitic structure with associated reduction of nitrogen‐containing functional groups. The structural change strongly affects where the Li ions are stored in the CNF electrodes. It is revealed that Li ions can be stored not only between the graphene layers, but also at the defect sites created by nitrogen functionalization. The latter is mainly responsible for the widely reported improved electrochemical performance of LIBs due to N‐doping of carbon materials. An optimized carbonization temperature of 550 °C is identified, which gives rise to a sufficiently high nitrogen content and thus a high capacity of the electrode.     

A Combination of X‐Ray Tomography and Carbon Binder Modeling: Reconstructing the Three Phases of LiCoO2 Li‐Ion Battery Cathodes

X‐ray tomography allows the active‐material domain (LiCoO₂) of Li‐ion battery cathodes to be imaged, but it is unable to resolve the carbon‐binder domain (CBD). Here, a new method for creating a complete 3D representation (virtual design) of all three phases of a cathode is provided; this includes the active‐material domain, the CBD, and the electrolyte‐filled pore space. It combines X‐ray tomographic data of active material with a statistically modeled CBD. Two different statistical CBD morphology models are compared as examples: i) a random cluster model representing a standard mixture of carbon black and polyvenylidene fluoride (PVDF) and ii) a fiber model. The transport parameters are compared in a charged and a discharged cathode. The results demonstrate that the CBD content and morphology changes the ionic and electronic transport parameters dramatically and thus cannot be neglected. Calculations yield that the fiber model shows up to three times higher electrical conductivity at the same CBD content (discharged case) and better ionic diffusion conditions for all CBD contents. In the charged case, the morphology impact on electrical conduction is small. This effective method to generate transport parameters for different CBDs can be transferred to other CBD morphologies and electrodes.     

安立泽联合胰岛素治疗单独胰岛素降糖欠佳的高龄2型糖尿病患者临床观察

目的：观察安立泽应用于单独胰岛素治疗血糖控制欠佳的高龄2型糖尿病患者的疗效及安全性。方法：200例高龄2型糖尿病胰岛素降糖欠佳的患者（空腹血糖控制在7．8．13．9mmol／L范围内）,随机分成对照组和治疗组,对照组采用胰岛素加安慰剂治疗80例;治疗组120例,分为A、B、c三组,每组40例,A、B、c三组分别在继续应用胰岛素治疗的基础上加服安立泽4mg／d、5mg／d、6mg／d,疗程三个月。观测治疗组和对照组治疗前后FPG及PPG、HbAlC、BMI和胰岛素用量的改变及治疗的安全性。结果：对照组和治疗组治疗前的各指标无明显差异（P〉0．05）;A、B、c三组在治疗后1个月和3个月FPG、PPG、H1）A1C均有明显的下降（P〈0．05,P〈0．01）,而对照组治疗前后FIG、PPG、HbAlC略有下降,差异不明显（P〉0．05）;A、B、c三组胰岛素的用量及体重指数较治疗前均略有下降,三组间无显著性差异;对照组和治疗组的不良反应发生率无显著差异。结论：对高龄2型糖尿病单用胰岛素治疗血糖控制欠佳的患者,加用安立泽治疗,可使糖尿病相关指标得以良好的控制,减少糖尿病患者每日胰岛素用量,临床毒副作用较小。