Color holographic display based on azo-dye-doped liquid crystal (Invited Paper)

A multiplexed holographic display video has been achieved by using a passive azo-dye-doped liquid crystal （LC） cell. Holograms formed in this cell can be refreshed in the order of several milliseconds. By angular multiplexing technique, dynamically multiplexed holographic videos are realized. Moreover, the reconstructed RGB images are merged into a color image, which illustrates the possibility of a color holographic three-dimensional （3D） display by holographic multiplexing of the LC cell.     

One-pot synthesis,characterization, and drug loading of polysaccharide-based nanoparticles with carboxy functional groups

Herein, various polysaccharide-based nanoparticles were synthesized from dextran, hydroxypropyl cellulose, and hydroxyethyl cellulose, respectively, by a self-assembly assisted approach. This approach enables us to prepare stable polysaccharide-based nanoparticles with carboxy functional groups directly from monomers without using any surfactant and organic solvent. The existence of abundant carboxyls in these polysaccharide-based nanoparticles provides them obvious pH sensitivity as verified by ¹H nuclear magnetic resonance as well as the potential in loading cationic drug.     

纳米尺度超声显影微囊的制备及性能表征简

采用双乳液-溶剂挥发法制备了内部包封氟碳液体的聚乳酸-甲氧基聚乙二醇两嵌段共聚物(MePEG-b-PLA)基超声显影纳米微囊;用2种不同嵌段比的MePEG-b-PLA共聚物研究共聚物组成与纳米囊性能的关系;选用聚乙烯醇(PVA)、羧甲基葡聚糖(CMG)和壳聚糖(CS) 3种乳化剂对纳米囊表面进行亲水性修饰. 对所制备纳米囊的粒径、Zeta电位、形貌和水溶液稳定性进行了表征. 结果表明,利用质量分数为1%的PVA和质量分数为1%的CMG组成的复配乳化剂和m(MePEG)：m(PLA)= 1：3的聚合物制得的纳米囊的平均粒径为432.9 nm,水溶液稳定性优良. 利用超声仪对纳米囊体外超声显影性能进行研究,结果表明,所得聚乳酸-甲氧基聚乙二醇纳米囊具有更好的中心成像区域灰度值和更持久的体外超声显影效果. 结合3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)比色法研究证实该纳米囊具有低细胞毒性. 在超声影像学领域具有良好的应用前景.     

Facile synthesis of magnetic microcapsules by synchronous formation of magnetite nanoparticles

Magnetite/poly (lactic acid) (PLA) composite microcapsules with controllable composition and magnetic property were synthesized by a facile interfacial coprecipitation joint double emulsion–solvent evaporation process. In this method, the interfacial coprecipitation was performed at the water-in-oil (W₁/O) interface and the generated Fe₃O₄ nanoparticles were incorporated into PLA microcapsules simultaneously. The magnetite content of the resultant composite microcapsules can be controlled as high as 38 wt.%. This novel method not only simplifies the fabrication process but also improves the magnetic property of composite microcapsules.     

Rapid Analysis of Nitrate and Nitrite by Ion-Interaction Chromatography on a Monolithic Column

Ion-interaction chromatography with direct conductivity detection has been used for analysis of nitrate and nitrite. Chromatographic separation was performed on a monolithic silica-based C₁₈ column dynamically modified with tetrabutylammonium (TBA⁺). Using the optimized mobile phase, containing 2.0 mmol L^?1 TBA⁺ and 0.8 mmol L^?1 citrate (pH 6.0), delivered at a flow rate of 6.0 mL min^?1, separation of five anions (chloride, nitrite, bromide, nitrate, and sulfate) was achieved in only 40 s at a column temperature of 30 °C. The detection limits for nitrate and nitrite were 0.74 and 0.92 mg L^?1, respectively. The relative standard deviation (RSD, n = 5) of the retention times of nitrate and nitrite was 0.1% and RSD of chromatographic peak areas were 0.4 and 0.2%, respectively. The method was successfully used for analysis of the anions in groundwater. Recovery of nitrate and nitrite was 99.1 and 105%, respectively.     

纳微尺度层状MgAl固体碱催化解聚木质素磺酸钙制取含氧化合物的研究

在水热合成体系中引入羟基化合物制备纳微尺度层状镁铝水滑石前驱体(MgAl-LDHs), 通过正交实验优化合成工艺参数, 焙烧后得到固体碱氧化物(MgAlO_x); 采用X射线衍射(XRD)、 扫描电子显微镜(SEM)和二氧化碳程序升温脱附(CO₂-TPD)对水滑石前驱体及固体碱氧化物进行晶相、 形貌和碱度表征, 对MgAlO_x解聚木质素磺酸钙(CLS)的催化性能进行评价, 采用气相色谱(GC)、 气相色谱-质谱联用(GC-MS)和凝胶渗透色谱(GPC)对反应后气、 液和固三相产物组成规律进行分析. 结果表明, 在n(Mg)/n(Al)=3, pH=12, 180 ℃, 24 h条件下, 添加15%(体积分数)C₂H₅OH时, 可以制备晶粒尺寸140~230 nm的层状MgAl-LDHs, 在空气气氛下于600 ℃焙烧6 h得到MgAlO_x. 水热体系下固体碱氧化物对木质素磺酸钙解聚的优化条件为270 ℃, 4 h, 65% C₂H₅OH, m(MgAlO_x)/m(CLS)=1/2, 此时其气、 液和固三相产物的产率分别为4.50%, 58.30%和37.20%, 其中液相产物收率比纯木质素磺酸钙解聚提高了13.30%, 液相产物主要组成为酚类、 芳香类、 酯类和其它化合物, 含氧化合物总选择性为79.05%(酚类66.06%, 酯类12.99%), 反应后的MgAlO_x经焙烧氧化再生后, 循环使用4次仍具有较高的活性和稳定性.     

Effect of inorganic salt on partition of high‐polarity parishins in two‐phase solvent systems and separation by high‐speed counter‐current chromatography from Gastrodia elata Blume

Parishins are high‐polarity and major bioactive constituents in Gastrodia elata Blume. In this study, the effect of several inorganic salts on the partition of parishins in two‐phase solvent systems was investigated. Adding ammonium sulfate, which has a higher solubility in water, was found to significantly promote the partition of parishins in the upper organic polar solvents. Based on the results, a two‐phase solvent system composed of butyl alcohol/acetonitrile/near‐saturated ammonium sulfate solution/water (1.5:0.5:1.2:1, v/v/v/v) was used for the purification of parishins by high‐speed counter‐current chromatography. Fractions obtained from high‐speed counter‐current chromatography were subjected to semi‐preparative high‐performance liquid chromatography to remove salt and impurities. As a result, parishin E (6.0 mg), parishin B (7.8 mg), parishin C (3.2 mg), gastrodin (15.3 mg), and parishin A (7.3 mg) were isolated from water extract of Gastrodia elata Blume (400 mg). These results demonstrated that adding inorganic salt that has high solubility in water to the two‐phase solvent system in high‐speed counter‐current chromatography was a suitable approach for the purification of high‐polarity compounds.     

A Mesoporous Nanorattle‐Structured Pd@PtRu Electrocatalyst

Pt‐based nanomaterials play important roles in the catalytic process toward oxygen reduction reaction (ORR). Rationally regulating the composition and morphology of the catalysts could enhance the catalytic performance effectively. In this work, an effective method is presented to synthesize Pd@ mesoporous PtRu nanorattles (Pd@mPtRu NRs) containing a Pd core and a mesoporous PtRu shell. Owing to the unique structure and PtRu alloy composition, the prepared Pd@mPtRu NRs exhibit an enhanced catalytic performance and durability toward ORR relative to mesoporous PtRu hollow nanoparticles (mPtRu HNs) and commercial Pt/C. The proposed approach may provide a general way to synthesize Pt‐based yolk‐shell structures with different compositions.     

IDUS、CT和MRCP对胆道恶性梗阻的诊断价值

目的探讨腔内超声（IDUS）、CT和磁共振胰胆管造影（MRCP）和对胆道恶性梗阻的诊断价值。方法回顾性分析53例胆道恶性梗阻患者的IDUS、CT和MRCP检查结果,比较3种影像学检查方法对胆道恶性梗阻的图像特征和诊断情况。结果IDUS、CT和MRCP对胆道恶性梗阻定位诊断准确率分别为65.31%、82.98%和82.93%,差异有统计学意义（P＜0.05）;而定性诊断准确率分别为63.27%、74.47%和75.61%,差异无统计学意义（P＞0.05）。3种影像学检查方法均能显示胆道恶性梗阻的部位、数量和回声/密度/信号特征：CT和MRCP对壶腹癌定位诊断、胰头癌定性诊断均有较高符合率。IDUS对胆管狭窄性质的阴性预测能力明显高于CT和MRCP（P＜0.05）。结论IDUS、CT和MRCP均能清晰显示胆道恶性梗阻的特征,各有优势,具有较高的应用价值。     

高效凝胶过滤色谱法（光电二极管阵列检测器）分离、测定巴豆毒蛋白

巴豆毒蛋白粗提液在高效蛋白柱上分离，用光电二极管阵列检测器给出光谱信号，判断所需蛋白的峰，并利用光谱图和反相高效液相色谱来确认分离峰的纯度；在高效蛋白柱上测定了巴豆毒蛋白的分子量；利用离子交个邻苯二甲醛柱后衍生法测定了巴豆毒蛋白的氨基酸含量。