(−)-Naringenin 4′,7-dimethyl Ether Isolated from Nardostachys jatamansi Relieves Pain through Inhibition of Multiple Channels

(−)-Naringenin 4′,7-dimethyl ether ((−)-NRG-DM) was isolated for the first time by our lab from Nardostachys jatamansi DC, a traditional medicinal plant frequently used to attenuate pain in Asia. As a natural derivative of analgesic, the current study was designed to test the potential analgesic activity of (−)-NRG-DM and its implicated mechanism. The analgesic activity of (−)-NRG-DM was assessed in a formalin-induced mouse inflammatory pain model and mustard oil-induced mouse colorectal pain model, in which the mice were intraperitoneally administrated with vehicle or (−)-NRG-DM (30 or 50 mg/kg) (n = 10 for each group). Our data showed that (−)-NRG-DM can dose dependently (30~50 mg/kg) relieve the pain behaviors. Notably, (−)-NRG-DM did not affect motor coordination in mice evaluated by the rotarod test, in which the animals were intraperitoneally injected with vehicle or (−)-NRG-DM (100, 200, or 400 mg/kg) (n = 10 for each group). In acutely isolated mouse dorsal root ganglion neurons, (−)-NRG-DM (1~30 μM) potently dampened the stimulated firing, reduced the action potential threshold and amplitude. In addition, the neuronal delayed rectifier potassium currents (I_K) and voltage-gated sodium currents (I_Na) were significantly suppressed. Consistently, (−)-NRG-DM dramatically inhibited heterologously expressed Kv2.1 and Nav1.8 channels which represent the major components of the endogenous I_K and I_Na. A pharmacokinetic study revealed the plasma concentration of (−)-NRG-DM is around 7 µM, which was higher than the effective concentrations for the I_K and I_Na. Taken together, our study showed that (−)-NRG-DM is a potential analgesic candidate with inhibition of multiple neuronal channels (mediating I_K and I_Na).     

水包油包固体乳化法制备蛋白药物缓释微球

以牛血清白蛋白(BSA)为模型药物, 研究了一种新型载药微球的水包油包固体(S/O/W)乳化法. 用纳米尺寸的SiO2吸附溶液中的BSA, 得到粒径约为30 nm的含药粒子, 再用PLGA包裹含药粒子. 考察不同制备条件对载药量和包封率的影响, 并与传统的双乳法(W/O/W)进行了对比, 发现该制备方法提高了药物的载药量(由2.5%到3.1%)和包封率(由72%到90%以上), 同时提高了药物活性.     

表面电荷与体陷阱对GaN基HEMT器件热电子和量子效应的影响研究

研究了GaN基HEMT器件表面电荷和体陷阱的变化对输出特性的影响.通过分析表面电荷与体陷阱对电流坍塌效应、饱和电流和膝点电压的影响,初步确定了其变化关系.研究结果显示表面电荷的增加能够耗尽二维电子气,减弱电流坍塌效应,降低饱和电流,使膝点电压非正常后移.同时,体陷阱的减小可以有效减弱电流坍塌效应,增大饱和电流,且膝点电压基本保持不变.晶格温度较低时,热电子效应和量子隧穿效应对电流坍塌效应影响显著.采用流体动力学模型,分析了引起电流坍塌效应的内在物理机制,并获得了器件设计和制备的优化方案. 关键词： GaN-HEMT器件 电流坍塌效应 热电子效应 表面电荷     

A Decoherence-Reduction Scheme by Waveguides in Quantum Information Processing

Based on the result of cavity quantum electrodynamics, we suggest a method, in which the Fabry-Perot cavity or the confocal cavity is replaced by a waveguide with the size comparable to the wavelength of the photon, to reduce decoherence caused by spontaneous emission in quantum information processing, especially in the realization of quantum computation. Since a waveguide has a lowest cutoff frequency while a Fabry-Perot cavity or a confocal cavity has none, the spontaneous emission of excited atoms will be forbidden in an ideal waveguide with an appropriate size. To avoid the influence of the non-ideal conducting walls on the atom in a realistic waveguide, which will lead to decoherence, we suggest that the waveguide should be coated by a thin film of transparent insulating medium. In our method, the quantum information is represented by a multi-level atom or molecule; any two of its levels can be used to represent a qubit in principle. Our method greatly extends the choice of the material to be used in the realization of quantum computation, and it can be used in most schemes to reduce the decoherence caused by spontaneous emission.     

色谱分析中校准曲线制作的探讨

利用实验数据探讨了色谱分析中校准曲线制作过程中线性范围、浓度设置和原点处理方式对分析精确度的影响。     

Unimolecular artificial transmembrane channel with terminal dihydrogen phosphate groups showing transport selectivity for ammonium

A new artificial transmembrane channel molecule bearing dihydrogen phosphate groups has been synthesized.The terminal dihydrogen phosphate groups enable the channel to be highly negatively charged at both ends of the channel structures.The artificial channel could incorporate into the lipid bilayer efficiently under low concentration.The channel displays high NH4+/K+selectivity due to the electrostatic interaction and hydrogen bonding between NH4+and the terminal dihydrogen phosphate groups.     

电子碰撞下氢原子单离化反应三重微分散射截面的计算

在共面非对称几何条件下，利用能壳上跃迁矩阵元的后滞形式和双势公式，对快电子碰撞下氢原子的单离化，提出了一个新的计算方法.通过分解动能算符，并且略去两电子的质心运动和相对运动的指数因子，对快电子采用平面波的近似形式，得到了库仑三体问题的近似解.散射振幅可以表示成两个因子乘积的形式，即结构散射因子T₂和关联因子T12.采用渐近级数展开和最佳截断的方法讨论了T₂和T₁₂对三重微分散射 截面的影响. 关键词： （e;2e）反应 三重微分截面 二体峰值 反冲峰值     

具有单分子磁行为的二维Dy(Ⅲ)-配合物

在水热条件下,利用刚性配体Hapca(3-氨基吡嗪-2-羧酸)合成了一例基于双核镝结构基元的二维网格配合物[Dy₂(apca)₄(OH)₂(H₂O)₂]_n(1)。磁性研究表明：该配合物显示铁磁耦合,并具有典型的慢弛豫行为,其弛豫时间τ₀=9.47×10^-7 s,各向异性能垒U_eff/k_B=73.7 K,是一例少见的具有单分子磁行为的镧系二维网格配合物。     

飞秒光纤激光相干合成技术最新进展

飞秒光纤激光器具有平均功率高、散热性能佳、光束质量好和空间体积小等优势,在基础研究、工业加工、生物医疗等方面得到越来越广泛的应用.相干合成技术能够有效克服光纤中有害的非线性效应和热效应的影响,进一步提高飞秒光纤激光器输出的脉冲能量和平均功率.本文介绍高功率飞秒光纤激光器相干合成的基本技术路线,重点阐述相干合成技术中关于填充孔径相干合成与平铺孔径相干合成的最新研究进展,并详细介绍相干合成技术中不同类型主动相位锁定技术的基本原理.相信在不远的将来,飞秒光纤激光相干合成系统的单脉冲能量和平均功率将不断攀升,从而开创许多崭新的研究领域.     

Screening prolyl hydroxylase domain 2 inhibitory activity of traditional Chinese medicine by CZE-UV

Prolyl hydroxylase domain 2 (PHD2) is a key enzyme regulating the expression of hypoxia inducible factor (HIF). Its inhibitors can improve the expression of HIF and downstream genes, which can treat hypoxia-related diseases. Therefore, the establishment of a reliable PHD2 inhibitors screening method is of great significance for the drug development of hypoxia-related diseases. In this work, an accurate, rapid, and simple screening method for PHD2 inhibitors was introduced by capillary zone electrophoresis (CZE). In order to improve the detection sensitivity, the derivative reaction of α-ketoglutaric acid (α-OG) and 1,2-diaminobenzene (OPD) was used to enhance the UV absorption of α-OG (the substrate in the enzymatic reaction). The CZE method selected 20 mM Na₂B₄O₇ buffer (pH 9.0) as the separation buffer, +25 kV as the separation voltage, 25°C as the cartridge temperature, and 210 nm as the detection wavelength. Under this condition, the analysis of a single sample can be realized within 9 min. Compared with the existing reported methods, the present work can directly screen the PHD2 inhibitory activity of traditional Chinese medicine (TCM) extracts, which is of significance for the target-purification of bioactive individual compounds from TCMs. Under the optimal conditions, the PHD2 inhibitor screening platform was successfully established, and it was found that 70% methanol/water extracts of Astragali Radix and Codonopsis pilosula had good PHD2 inhibitory activity. Furthermore, the present work provides a novel approach for screening the PHD2 inhibitory activity of TCM extracts and the discovery of anti-hypoxia bioactive compounds.